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Publisher: Elsevier   (Total: 3185 journals)

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Showing 1 - 200 of 3185 Journals sorted alphabetically
Academic Pediatrics     Hybrid Journal   (Followers: 37, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 26, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 100, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 28, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 40, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 6)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 7)
Acta Astronautica     Hybrid Journal   (Followers: 433, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 28, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 3)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 11, SJR: 0.18, CiteScore: 1)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 308, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 12, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1, SJR: 1.793, CiteScore: 6)
Acta Poética     Open Access   (Followers: 4, SJR: 0.101, CiteScore: 0)
Acta Psychologica     Hybrid Journal   (Followers: 25, SJR: 1.331, CiteScore: 2)
Acta Sociológica     Open Access   (Followers: 1)
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.052, CiteScore: 2)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3, SJR: 0.374, CiteScore: 1)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.344, CiteScore: 1)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 7, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 8)
Acute Pain     Full-text available via subscription   (Followers: 15, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 18, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 9, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 11, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 23)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 182, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 12, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 17, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 29, SJR: 0.126, CiteScore: 0)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 11, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 11, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 24, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 15, SJR: 0.572, CiteScore: 2)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.61, CiteScore: 7)
Advances in Botanical Research     Full-text available via subscription   (Followers: 2, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 33, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 1.453, CiteScore: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 1.992, CiteScore: 5)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 5)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 29, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 26, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20, SJR: 1.977, CiteScore: 8)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.205, CiteScore: 1)
Advances in Dermatology     Full-text available via subscription   (Followers: 15)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 13)
Advances in Digestive Medicine     Open Access   (Followers: 12)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Ecological Research     Full-text available via subscription   (Followers: 44, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 29, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 8)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 51, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 66, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Genetics     Full-text available via subscription   (Followers: 21, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 10, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 7, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 26, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 24)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 3, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 10, SJR: 1.163, CiteScore: 2)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.938, CiteScore: 3)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6, SJR: 0.176, CiteScore: 0)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 9, SJR: 0.682, CiteScore: 2)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 21, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 12, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 8, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 5, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 24)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.182, CiteScore: 0)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 5)
Advances in Oncobiology     Full-text available via subscription   (Followers: 2)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18, SJR: 1.875, CiteScore: 4)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.174, CiteScore: 0)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 27, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 18)
Advances in Pharmacology     Full-text available via subscription   (Followers: 17, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 0.574, CiteScore: 1)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.109, CiteScore: 1)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 10)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 6)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 0.791, CiteScore: 2)
Advances in Psychology     Full-text available via subscription   (Followers: 66)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (Followers: 1, SJR: 0.263, CiteScore: 1)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.101, CiteScore: 0)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 6)
Advances in Space Research     Full-text available via subscription   (Followers: 418, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 13, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 37, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 20)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
Advances in Virus Research     Full-text available via subscription   (Followers: 6, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 53, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 381, SJR: 0.796, CiteScore: 3)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.42, CiteScore: 2)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.296, CiteScore: 0)
Ageing Research Reviews     Hybrid Journal   (Followers: 12, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 471, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 18, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 45, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 4)
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 58, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 7, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 12, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 11)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 2, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 11, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 10, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 54, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 6, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 6, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 58, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 63, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 46, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 12)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 37, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 29, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 36, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 50)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3, SJR: 1.967, CiteScore: 2)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 250, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 66, SJR: 3.184, CiteScore: 4)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 5, SJR: 0.265, CiteScore: 0)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.289, CiteScore: 1)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, CiteScore: 1)
American J. of Pathology     Hybrid Journal   (Followers: 32, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 28, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 39, SJR: 1.141, CiteScore: 2)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.767, CiteScore: 1)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 7)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.144, CiteScore: 3)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 66, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 24, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription   (Followers: 1)
Anales de Pediatría     Full-text available via subscription   (Followers: 3, SJR: 0.277, CiteScore: 0)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription  
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 5, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 44, SJR: 1.512, CiteScore: 5)
Analytica Chimica Acta : X     Open Access  
Analytical Biochemistry     Hybrid Journal   (Followers: 209, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 13, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 14)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 25, SJR: 0.683, CiteScore: 2)
Angiología     Full-text available via subscription   (SJR: 0.121, CiteScore: 0)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1, SJR: 0.111, CiteScore: 0)
Animal Behaviour     Hybrid Journal   (Followers: 217, SJR: 1.58, CiteScore: 3)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6, SJR: 0.937, CiteScore: 2)
Animal Reproduction Science     Hybrid Journal   (Followers: 7, SJR: 0.704, CiteScore: 2)

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Similar Journals
Journal Cover
Academic Radiology
Journal Prestige (SJR): 1.015
Citation Impact (citeScore): 2
Number of Followers: 26  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1076-6332
Published by Elsevier Homepage  [3185 journals]
  • Developing and Evaluating a Simulator for Complex IVC Filter Retrieval
    • Abstract: Publication date: Available online 20 September 2019Source: Academic RadiologyAuthor(s): Nam S. Hoang, Benjamin H. Ge, William T. KuoRationale and ObjectivesSimulation models allow trainees to acquire and develop procedural skills without compromising patient safety. Complex inferior vena cava (IVC) filter retrieval requires the operator to be proficient at using devices, such as endobronchial forceps, and advanced techniques to carefully dissect free embedded filter tips encased in fibrous tissue adherent to the IVC. Therefore, it is important to develop an effective, inexpensive model to simulate tip-embedded IVC filter retrieval.Materials and MethodsSilicone tubes (Flexi-Seal SIGNAL, ConvaTec Inc., Skilman, NJ), IVC filters (Cook Günther Tulip Vena Cava Filter, Cook Medical, Bloomington, IN), and endobronchial forceps (Lymol Medical, Woburn, MA) were obtained to assemble the model. A total of 12 combinations of adhesive binding methods were used to adhere IVC filter fragments to the silicone tubes, and these were blind tested. A single operator with over 10 years of experience using forceps scored the adhesives subjectively on a three-point scale for adherence, elasticity, and tactile feel. The adhesive most similar to IVC fibrous tissue was selected to assemble the final tip-embedded IVC filter model. 20 trainees were then assigned to practice on the model. A 3-point scale scoring metric objectively measured confidence before and after training on the model.ResultsSil-poxy Silicone Adhesive (Smooth-On, Macungie, PA) was found to be the most similar to human IVC fibrous tissue with an average score of 3 of 3 on all metrics. Comparing scores from before and after use of the model, trainee confidence improved significantly (p < 0.1) in all three categories from 1.20 to 2.10 (handling forceps), 1.05 to 2.15 (understanding tactile feel of fibrous tissue), and 1.05 to 1.70 (overall confidence).ConclusionThe development of a low-cost simulator for embedded IVC filters is feasible and can be used to improve trainee confidence and skill for complex IVC filter retrieval.
  • Medical 3D Printing Cost-Savings in Orthopedic and Maxillofacial Surgery:
           Cost Analysis of Operating Room Time Saved with 3D Printed Anatomic Models
           and Surgical Guides
    • Abstract: Publication date: Available online 18 September 2019Source: Academic RadiologyAuthor(s): David H. Ballard, Patrick Mills, Richard Duszak, Jeffery A. Weisman, Frank J. Rybicki, Pamela K. WoodardRATIONALE AND OBJECTIVEThree-dimensional (3D) printed anatomic models and surgical guides have been shown to reduce operative time. The purpose of this study was to generate an economic analysis of the cost-saving potential of 3D printed anatomic models and surgical guides in orthopedic and maxillofacial surgical applications.MATERIALS AND METHODSA targeted literature search identified operating room cost-per-minute and studies that quantified time saved using 3D printed constructs. Studies that reported operative time differences due to 3D printed anatomic models or surgical guides were reviewed and cataloged. A mean of $62 per operating room minute (range of $22–$133 per minute) was used as the reference standard for operating room time cost. Different financial scenarios were modeled with the provided cost-per-minute of operating room time (using high, mean, and low values) and mean time saved using 3D printed constructs.RESULTSSeven studies using 3D printed anatomic models in surgical care demonstrated a mean 62 minutes ($3720/case saved from reduced time) of time saved, and 25 studies of 3D printed surgical guides demonstrated a mean 23 minutes time saved ($1488/case saved from reduced time). An estimated 63 models or guides per year (or 1.2/week) were predicted to be the minimum number to breakeven and account for annual fixed costs.CONCLUSIONBased on the literature-based financial analyses, medical 3D printing appears to reduce operating room costs secondary to shortening procedure times. While resource-intensive, 3D printed constructs used in patients’ operative care provides considerable downstream value to health systems.
  • Seeing With Sound: Educational Insights of the 200th Anniversary of
           Laennec's Magnum Opus
    • Abstract: Publication date: Available online 17 September 2019Source: Academic RadiologyAuthor(s): Amer M. Mohiuddin, Richard B. Gunderman
  • Essential Elements of Natural Language Processing: What the Radiologist
           Should Know
    • Abstract: Publication date: Available online 17 September 2019Source: Academic RadiologyAuthor(s): Po-Hao ChenNatural language is ubiquitous in the workflow of medical imaging. Radiologists create and consume free text in their daily work, some of which can be amenable to enhancements through automatic processing. Recent advancements in deep learning and “artificial intelligence” have had a significant positive impact on natural language processing (NLP). This article discusses the history of how researchers have extracted data and encoded natural language information for analytical processing, starting from NLP's humble origins in hand-curated, linguistic rules. The evolution of medical NLP including vectorization, word embedding, classification, as well as its use in automated speech recognition, are also explored. Finally, the article will discuss the role of machine learning and neural networks in the context of significant, if incremental, improvements in NLP.
  • Technical and Clinical Factors Affecting Success Rate of a Deep Learning
           Method for Pancreas Segmentation on CT
    • Abstract: Publication date: Available online 16 September 2019Source: Academic RadiologyAuthor(s): Mohammad Hadi Bagheri, Holger Roth, William Kovacs, Jianhua Yao, Faraz Farhadi, Xiaobai Li, Ronald M. SummersPurposeAccurate pancreas segmentation has application in surgical planning, assessment of diabetes, and detection and analysis of pancreatic tumors. Factors that affect pancreas segmentation accuracy have not been previously reported. The purpose of this study is to identify technical and clinical factors that adversely affect the accuracy of pancreas segmentation on CT.Method and MaterialsIn this IRB and HIPAA compliant study, a deep convolutional neural network was used for pancreas segmentation in a publicly available archive of 82 portal-venous phase abdominal CT scans of 53 men and 29 women. The accuracies of the segmentations were evaluated by the Dice similarity coefficient (DSC). The DSC was then correlated with demographic and clinical data (age, gender, height, weight, body mass index), CT technical factors (image pixel size, slice thickness, presence or absence of oral contrast), and CT imaging findings (volume and attenuation of pancreas, visceral abdominal fat, and CT attenuation of the structures within a 5 mm neighborhood of the pancreas).ResultsThe average DSC was 78% ± 8%. Factors that were statistically significantly correlated with DSC included body mass index (r = 0.34, p < 0.01), visceral abdominal fat (r = 0.51, p < 0.0001), volume of the pancreas (r = 0.41, p = 0.001), standard deviation of CT attenuation within the pancreas (r = 0.30, p = 0.01), and median and average CT attenuation in the immediate neighborhood of the pancreas (r = −0.53, p < 0.0001 and r = -0.52, p < 0.0001). There were no significant correlations between the DSC and the height, gender, or mean CT attenuation of the pancreas.ConclusionIncreased visceral abdominal fat and accumulation of fat within or around the pancreas are major factors associated with more accurate segmentation of the pancreas. Potential applications of our findings include assessment of pancreas segmentation difficulty of a particular scan or dataset and identification of methods that work better for more challenging pancreas segmentations.
  • Comparison of Mass Size Measurements: Synthesized Mammography Versus
           Full-Field Digital Mammography
    • Abstract: Publication date: Available online 16 September 2019Source: Academic RadiologyAuthor(s): Halit Nahit Şendur, Mahi Nur Cerit, Serap Gültekin, Emetullah Cindil, Pınar KılıçObjectivesTo compare mass size measurements between synthesized mammography (SM) and full-field digital mammography (FFDM), and to assess interobserver agreement for those measurements.Materials and MethodsOne hundred and forty-three patients who underwent FFDM and digital breast tomosynthesis acquisitions during the same compression session were included in the study. Two observers with four-and 1-year experience with digital breast tomosynthesis and SM images, respectively, measured mass sizes independently in two different sessions that were 2 weeks apart, and were blinded to each other. The first session included only FFDM images, and the second session included only SM images. Largest dimension of masses was measured in millimeters. Paired t test was used to compare differences in size measurements between FFDM and SM images. Intraclass correlation coefficient test was used to analyze interobserver agreement. Bland-Altman analyses were performed to evaluate agreements between the imaging techniques and between the observers.ResultsThe mean mass sizes on FFDM and SM images were 20.27 ± 14.10 and 18.50 ± 13.05 mm, respectively, for the first observer and 21.56 ± 14.84 and 19.89 ± 13.68 mm, respectively, for the second observer. The mass size measurements were significantly different between FFDM and SM for both observers (p
  • Prospective Comparison of 70-kVp Single-Energy CT versus Dual-Energy CT:
           Which is More Suitable for CT Angiography with Low Contrast Media
    • Abstract: Publication date: Available online 16 September 2019Source: Academic RadiologyAuthor(s): Morikatsu Yoshida, Takeshi Nakaura, Takada Sentaro, Shota Tanoue, Hatsuki Inada, Daisuke Utsunomiya, Naritsugu Sakaino, Kazunori Harada, Yasuyuki YamashitaRationale and ObjectivesTo compare the objective and subjective image qualities between single-energy computed tomography (CT) at 70 kVp and virtual monoenergetic imaging (VMI) of dual-source dual-energy CT for CT angiography with 180 mgI/kg.Materials and MethodsTotal 63 patients scanned with 180 mgI/kg were randomly divided into two groups: Group A (32 patients) underwent CT angiography at 70-kVp, and Group B (31 patients) underwent dual-energy CT. VMI sets were generated at 10-keV increments between 40 and 100 keV. We calculated aortic attenuation, contrast-to-noise-ratio (CNR), signal-to-noise-ratio, figure of merit of CNR, and effective dose for each protocol. Three radiologists scored overall image quality and various arteries’ visibility using a four-point scale. Quantitative and qualitative comparisons between 70 kVp and VMI with the highest CNR were performed with the two-tailed t test or Kruskal–Wallis test.ResultsThe 40-keV images offered the highest CNR among VMIs. Aortic attenuation at 70 kVp was significantly lower than that at 40 keV (p < 0.001). However, the signal-to-noise-ratio, CNR, and figure of merit of CNR were significantly higher at 70 kVp than those at 40-keV (p < 0.001, p < 0.05, and p < 0.05, respectively). The effective dose of each group was almost equal. The qualitative visibility scores for various arteries, except the ascending and upper-abdominal aorta, were also better at 70 kVp than those at 40 keV.ConclusionAortic attenuation at 70 kVp with 180 mg I/kg was lower than that of VMI at 40 keV, and the objective and subjective image qualities were higher at 70 kVp than those at 40 keV.
  • Coronary Artery Plaque Burden in Smokers and Never-Smokers: Quantification
           With Cardiac CT
    • Abstract: Publication date: Available online 14 September 2019Source: Academic RadiologyAuthor(s): Felix G. Meinel
  • Potential Role of Convolutional Neural Network Based Algorithm in Patient
           Selection for DCIS Observation Trials Using a Mammogram Dataset
    • Abstract: Publication date: Available online 14 September 2019Source: Academic RadiologyAuthor(s): Simukayi Mutasa, Peter Chang, Eduardo P. Van Sant, John Nemer, Michael Liu, Jenika Karcich, Gita Patel, Sachin Jambawalikar, Richard HaRationale and ObjectivesWe investigated the feasibility of utilizing convolutional neural network (CNN) for predicting patients with pure Ductal Carcinoma In Situ (DCIS) versus DCIS with invasion using mammographic images.Materials and MethodsAn IRB-approved retrospective study was performed. 246 unique images from 123 patients were used for our CNN algorithm. In total, 164 images in 82 patients diagnosed with DCIS by stereotactic-guided biopsy of calcifications without any upgrade at the time of surgical excision (pure DCIS group). A total of 82 images in 41 patients with mammographic calcifications yielding occult invasive carcinoma as the final upgraded diagnosis on surgery (occult invasive group). Two standard mammographic magnification views (CC and ML/LM) of the calcifications were used for analysis. Calcifications were segmented using an open source software platform 3D Slicer and resized to fit a 128 × 128 pixel bounding box. A 15 hidden layer topology was used to implement the neural network. The network architecture contained five residual layers and dropout of 0.25 after each convolution. Five-fold cross validation was performed using training set (80%) and validation set (20%). Code was implemented in open source software Keras with TensorFlow on a Linux workstation with NVIDIA GTX 1070 Pascal GPU.ResultsOur CNN algorithm for predicting patients with pure DCIS achieved an overall diagnostic accuracy of 74.6% (95% CI, ±5) with area under the ROC curve of 0.71 (95% CI, ±0.04), specificity of 91.6% (95% CI, ±5%) and sensitivity of 49.4% (95% CI, ±6%).ConclusionIt's feasible to apply CNN to distinguish pure DCIS from DCIS with invasion with high specificity using mammographic images.
  • Evaluation of Postoperative Changes in Patellar and Quadriceps Tendons
           after Total Knee Arthroplasty–A Comprehensive Analysis by Shear Wave
           Elastography, Power Doppler and B-mode Ultrasound
    • Abstract: Publication date: Available online 14 September 2019Source: Academic RadiologyAuthor(s): Valentin Quack, Marcel Betsch, Julian Hellmann, Jörg Eschweiler, Simone Schrading, Matthias Gatz, Björn Rath, Markus Tingart, Markus Laubach, Christiane K. Kuhl, Timm DirrichsRationale and ObjectivesUp to now, the diagnosis of tendinopathies is based on conventional B-mode-ultrasound (B-US), Power Doppler-ultrasound (PD-US), and magnetic resonance imaging. In the past decade, Shear Wave Elastography (SWE) has been introduced in tendon imaging, for example in athletes or patients suffering from tendinopathy. SWE allows real-time quantification of tissue stiffness, and, by this, the assessment of the mechanical properties of a tendon and its changes during acute disease and tendon healing. So far there are no ultrasound-based studies that have evaluated postoperative tendon changes, anatomical and mechanical properties and tendon healing of the patellar, and quadriceps tendon following Total Knee Arthroplasty (TKA). The purpose of this prospective study was two-fold: first to analyze morphologic, vascular, and mechanical properties of patellar and quadriceps tendons in patients following TKA; and, second to evaluate possible changes thereof and their visibility in the course of time.Materials and MethodsObservational cross-sectional, IRB-approved study in 63 postoperative patients with a total of 76 total knee arthroplasties (50 unilateral, 13 bilateral) and 50 nonoperated knees for comparison, resulting in 152 postoperative patellar- and quadriceps and 100 nonoperated patellar- and quadriceps-tendons for comparative analysis. For further examination, we divided the 63 patients into two groups according to the duration since surgery (group A < 24 months; group B> 24 months). All patients completed a standardized questionnaire, furthermore the Knee Society score and the Knee Society function score. The amount of experienced pain was assessed using the ordinal numeric rating scale and the presence of anterior knee pain was examined. Subsequently every participant underwent a standardized multimodal ultrasound protocol consisting of B-US, PD-US, and SWE of the left and right patellar and quadriceps tendons.ResultsUsing the different US-modalities, operated patellar, and quadriceps tendons (n = 152) were significantly more frequent classified as pathological (B-US) (p < 0.001), the mean Ohberg score was significantly higher (PD-US) (p < 0.001), and the tendons were significantly softer (SWE) than their nonoperated counterparts (n = 100). Mean SWE-value of postoperative patellar tendons was 45.66 ± 14.84 kPa versus 60.08 ± 19.13 kPa in nonoperated knees (p < 0.001). Mean SWE-value of postoperative quadriceps tendons was 35.73 ± 15.66 kPa versus 52.69 ± 16.20 kPa in nonoperated knees (p < 0.001). Comparing the two postoperative groups (group A and B), we recognized a significant decrease of pathologically classified patellar and quadriceps tendons (B-US and PD-US) in group B. The early postoperatively reduced SWE values slightly increased during the course of time.ConclusionAfter TKA, patellar, and quadriceps tendons show significant measurable alterations in B-US, PD-US, and SWE. Especially a significant decrease of tendon stiffness in operated knees, as assessed by SWE, might be a surrogate marker for changed mechanical properties. These alterations improve, the longer ago the surgery was. The quantitative information obtained by SWE could be of particular interest in follow-up and therapy monitoring after TKA. Knowledge about tendon stiffness and it's varieties in different population groups (e.g. athletes, elderly, postoperative patients) is crucial to sonographically rate a tendon as “healthy” or “diseased.”
  • Preoperative Evaluation of Peritoneal Disease in Ovarian Cancer: Balancing
           Accuracy and Clinical Utility
    • Abstract: Publication date: Available online 12 September 2019Source: Academic RadiologyAuthor(s): Molly E. Roseland, Katherine E. Maturen
  • Adaptive Tutorials Versus Web-Based Resources in Radiology: A Mixed
           Methods Analysis of Efficacy and Engagement in Senior Medical Students
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Stuart W.T. Wade, Michelle Moscova, Nicodemus Tedla, Daniel A. Moses, Noel Young, Merribel Kyaw, Gary M. VelanRationale and ObjectivesRadiology education is suited to delivery via e-learning which may be used to fill gaps in knowledge and help prepare medical students for internship. There is limited evidence of effectiveness of adaptive tutorials, a form of e-learning in a senior medical student cohort.Materials and MethodsA randomized mixed methods crossover trial was performed to assess effectiveness of adaptive tutorials on engagement and understanding of appropriate use and interpretation of basic imaging studies. Eighty-one volunteer medical students from years 5 and 6 of a 6-year program were randomly allocated to one of two groups. In the first phase of the trial on head CT, one group received access to adaptive tutorials and the other to peer-reviewed web-based resources. A cross over was performed and the second phase of the trial addressing chest CT commenced. Examination style assessments were completed at the end of each phase. At the trial's conclusion, an online questionnaire was provided to evaluate student perceptions of engagement and efficacy of each educational resource.ResultsAdaptive tutorial groups in both phases achieved higher mean scores than controls which were statistically significant in the first phase only. Students reported higher engagement and overall perceived value of the adaptive tutorials than controls.ConclusionAdaptive tutorials are overwhelmingly supported by senior medical students. Questionnaire responses suggest the engaging nature of the tutorials efficiently aids participation and knowledge retention which is in principle supported by test results.
  • Impact of Effective Detector Pixel and CT Voxel Size on Accurate
           Estimation of Blood Volume in Opacified Microvasculature
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Mahya Sheikhzadeh, Andrew J. Vercnocke, Shengzhen Tao, Kishore Rajendran, Shuai Leng, Erik L. Ritman, Cynthia H. McColloughRationale and ObjectivesThe purpose of this study was to determine the impact of effective detector-pixel-size and image voxel size on the accurate estimation of microvessel density (ratio of microvascular lumen volume/tissue volume) in an excised porcine myocardium specimen using microcomputed tomography (CT), and the ability of whole-body energy-integrating-detector (EID) CT and photon-counting-detector (PCD) CT to measure microvessel density in the same ex vivo specimen.Materials and MethodsPorcine myocardial tissue in which the microvessels contained radio-opaque material was scanned using a micro-CT scanner and data were generated with a range of detector pixel sizes and image voxel sizes from 20 to 260 microns, to determine the impact of these parameters on the accuracy of microvessel density estimates. The same specimen was scanned in a whole-body EID CT and PCD CT system and images reconstructed with 600 and 250 micron slice thicknesses, respectively. Fraction of tissue volume that is filled with opacified microvessels was determined by first subtracting the mean background attenuation value from all voxels, and then by summing the remaining attenuation.ResultsMicrovessel density data were normalized to the value measured at 20 µm voxel size, which was considered reference truth for this study. For emulated micro-CT voxels up to 260 µm, the microvessel density was underestimated by at most 11%. For whole-body EID CT and PCD CT, microvessel density was underestimated by 9.5% and overestimated by 0.1%, respectively.ConclusionOur data indicate that microvessel density can be accurately calculated from the larger detector pixels used in clinical CT scanners by measuring the increase of CT attenuation caused by these opacified microvessels.
  • To Score or Not to Score—The USMLE Debate Continues
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Priscilla J. Slanetz
  • The USMLE Step 1 Pass/Fail Reporting Proposal: Another View
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): J. Bryan Carmody, David Sarkany, Darel E. HeitkampThe Association of Program Directors in Radiology recently issued a statement endorsing continued reporting of results of the United States Medical Licensing Examination (USMLE) as a three-digit score. While this position was approved by the Association of Program Directors in Radiology Board of Directors, it does not reflect the opinions of all radiology program directors. Here, we present an argument in support of reporting USMLE results as pass/fail.As a psychometric instrument, the USMLE Step 1 is designed to assess basic science knowledge and intended to inform a binary decision on licensure. Due to a steadily-increasing burden of applications to review, program directors have increasingly relied upon scores for candidate screening. Such use has multiple adverse consequences. Student focus on Step 1 systematically devalues educational content not evaluated on the exam, and the reliance on Step 1 scores almost certainly works against efforts to increase workforce diversity. Moreover, the increasing pressure of “Step 1 Mania” has negative consequences for trainee mental health and wellness.Despite the widespread use of Step 1 scores to select applicants, there are little data to correlate scores to meaningful outcomes related to patient care or clinical practice. We find the current situation untenable, and believe a necessary first step toward reform is making Step 1 a pass/fail only examination.
  • Machine Learning to Differentiate T2-Weighted Hyperintense Uterine
           Leiomyomas from Uterine Sarcomas by Utilizing Multiparametric Magnetic
           Resonance Quantitative Imaging Features
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Masataka Nakagawa, Takeshi Nakaura, Tomohiro Namimoto, Yuji Iyama, Masafumi Kidoh, Kenichiro Hirata, Yasunori Nagayama, Hideaki Yuki, Seitaro Oda, Daisuke Utsunomiya, Yasuyuki YamashitaRationale and ObjectiveUterine leiomyomas with high signal intensity on T2-weighted imaging (T2WI) can be difficult to distinguish from sarcomas. This study assessed the feasibility of using machine learning to differentiate uterine sarcomas from leiomyomas with high signal intensity on T2WI on multiparametric magnetic resonance imaging.Materials and MethodsThis retrospective study included 80 patients (50 with benign leiomyoma and 30 with uterine sarcoma) who underwent pelvic 3 T magnetic resonance imaging examination for the evaluation of uterine myometrial smooth muscle masses with high signal intensity on T2WI. We used six machine learning techniques to develop prediction models based on 12 texture parameters on T1WI and T2WI, apparent diffusion coefficient maps, and contrast-enhanced T1WI, as well as tumor size and age. We calculated the areas under the curve (AUCs) using receiver-operating characteristic analysis for each model by 10-fold cross-validation and compared these to those for two board-certified radiologists.ResultsThe eXtreme Gradient Boosting model gave the highest AUC (0.93), followed by the random forest, support vector machine, multilayer perceptron, k-nearest neighbors, and logistic regression models. Age was the most important factor for differentiation (leiomyoma 44.9 ± 11.1 years; sarcoma 58.9 ± 14.7 years; p < 0.001). The AUC for the eXtreme Gradient Boosting was significantly higher than those for both radiologists (0.93 vs 0.80 and 0.68, p = 0.03 and p < 0.001, respectively).ConclusionMachine learning outperformed experienced radiologists in the differentiation of uterine sarcomas from leiomyomas with high signal intensity on T2WI.
  • A Call to Action – Our Radiology Chairs Are Burning Out
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Jonathan B. Kruskal, Alexander Norbash
  • Burnout in Chairs of Academic Radiology Departments in the United States
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Dhakshinamoorthy Ganeshan, Wei Wei, Wei YangObjectiveWe aimed to estimate the self-reported prevalence of burnout in chairs of academic radiology departments in the United States and identify factors associated with high burnout in chairs.Materials and MethodsAn anonymous cross-sectional online survey was conducted of members of the Society of Chairs of Academic Radiology Departments. Burnout was measured using the abbreviated Maslach Burnout Inventory Human Services Survey. Associations between survey participants’ characteristics and burnout were tested using Fisher's exact test and Wilcoxon rank sum test.ResultsOf the 123 chairs invited to complete the survey, 87 responded (response rate, 71%). The mean age of the participants was 58 years. The survey respondents had an average of 9 years of experience as department chair. The average number of work hours per week was 62 hours. Four participants (5%) of the academic chairs met all three criteria for high burnout including high emotional exhaustion, high depersonalization, and low personal accomplishment. Thirty-three participants (38%) had high emotional exhaustion and/or high depersonalization score. Low professional satisfaction score, low work-life balance satisfaction score, and low chair effectiveness score were significantly associated with high burnout. High emotional exhaustion and/or high depersonalization were significantly associated with numerous professional stressors. Lack of an institutional support group for chairs and lower number of faculty members in the department were significantly associated with burnout.ConclusionA significant proportion of chairs of academic radiology departments are experiencing 1 or more symptoms of burnout. Efforts to address burnout in radiology chairs should be initiated promptly at the national, institutional, and departmental levels.
  • Initial Clinical Experience with Stationary Digital Breast Tomosynthesis
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Yueh Z. Lee, Connor Puett, Christina R. Inscoe, Beilin Jia, Connie Kim, Ruth Walsh, Sora Yoon, Suk Jung Kim, Cherie M. Kuzmiak, Donglin Zeng, Jianping Lu, Otto ZhouRationale and ObjectivesA linear array of carbon nanotube-enabled x-ray sources allows for stationary digital breast tomosynthesis (sDBT), during which projection views are collected without the need to move the x-ray tube. This work presents our initial clinical experience with a first-generation sDBT device.Materials and MethodsFollowing informed consent, women with a “suspicious abnormality” (Breast Imaging Reporting and Data System 4), discovered by digital mammography and awaiting biopsy, were also imaged by the first generation sDBT. Four radiologists participated in this paired-image study, completing questionnaires while interpreting the mammograms and sDBT image stacks. Areas under the receiver operating characteristic curve were used to measure reader performance (likelihood of correctly identifying malignancy based on pathology as ground truth), while a multivariate analysis assessed preference, as readers compared one modality to the next when interpreting diagnostically important image features.ResultsFindings from 43 women were available for analysis, in whom 12 cases of malignancy were identified by pathology. The mean areas under the receiver operating characteristic curve was significantly higher (p < 0.05) for sDBT than mammography for all breast density categories and breast thicknesses. Additionally, readers preferred sDBT over mammography when evaluating mass margins and shape, architectural distortion, and asymmetry, but preferred mammography when characterizing microcalcifications.ConclusionReaders preferred sDBT over mammography when interpreting soft-tissue breast features and were diagnostically more accurate using images generated by sDBT in a Breast Imaging Reporting and Data System 4 population. However, the findings also demonstrated the need to improve microcalcification conspicuity, which is guiding both technological and image-processing design changes in future sDBT devices.
  • Shear Wave Elastography (SWE) of Asymptomatic Achilles Tendons: A
           Comparison Between Semiprofessional Athletes and the Nonathletic General
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Timm Dirrichs, Simone Schrading, Matthias Gatz, Markus Tingart, Christiane K. Kuhl, Valentin QuackRationale and ObjectivesIt has been shown that Shear Wave Elastography (SWE) is a useful tool to evaluate tendon stiffness, e.g. in diagnosing tendinopathies, as diseased or injured tendons are intra-individually softer than healthy ones. But reference values between different population groups are still missing. The purpose of this prospective clinical study was two-fold: First, to comparatively analyse Achilles tendon stiffness between asymptomatic semiprofessional athletes and an asymptomatic nonathletic control group. Second, to evaluate specificity, with which SWE is able to predict absence of clinical symptoms in asymptomatic individuals, compared to B-mode-Ultrasound (B-US) and Power Doppler-Ultrasound (PD-US).Materials and MethodsProspective clinical study in 68 asymptomatic healthy participants, 33 (48.5%) of them semiprofessional athletes with at least five training units of running per week and 35 (51.5 %) normal nonathletic persons, asymptomatic respectively. A consecutive of 136 Achilles tendons underwent standardized multi-modal ultrasound, consisting of B-US, PD-US, and SWE (Aixplorer, Supersonic). Pathologic structural changes at B-US, increased Doppler signal PD-US and quantitative ROI-based-analysis of tendon elasticity in kilopascal (kPa) were performed in all participants. Tendon stiffness was compared intra-individually between right and left side in each participant. SWE values between athletes and nonathletes were compared by using student's t test (p < 0.05). To evaluate the ability of different sonographic modalities in predicting "absence of clinical symptoms”, specificities of B-US, PD-US, and SWE were calculated and compared among each other.ResultsMean SWE-value for Achilles tendon was 183.8 kPa (± 98 kPa) in athletes and 103.6 kPa (± 30.5 kPa) in the nonathletic control group. The difference between athletes and non-athletes was statistically significant (p < 0.001). No significant differences were found intra-individually between right and left side: athlete mean: right: 187.2 kPa (SD ± 45.2 kPa)/left: 180.4 kPa (SD 39.7 kPa); nonathlete mean: right: 105.4 kPa (SD 34.9 kPa)/left: 101.8 kPa (SD 28.9 kPa). Specificity with which asymptomatic tendons were rated as “inconspicuous” was 60.6% for B-US, 93.9% for PD-US and 96.3% for SWE.ConclusionHealthy athletes exhibit significantly higher SWE-values in Achilles tendons than healthy nonathletic participants, which means that they have significantly stiffer tendons, possibly caused by repeated training. SWE is able to measure and display these effects. These interindividual differences should be taken into consideration, especially when rating a tendon as “healthy” or “diseased”, because a “softer” tendon does not necessarily mean to be affected.
  • Image Quality and ADC Assessment in Turbo Spin-Echo and Echo-Planar
           Diffusion-Weighted MR Imaging of Tumors of the Head and Neck
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Wannakamon Panyarak, Toru Chikui, Yasuo Yamashita, Takeshi Kamitani, Kazunori YoshiuraRationale and ObjectivesWe aimed to compare the distortion ratio (DR), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) between turbo spin-echo (TSE)-diffusion-weighted imaging (DWI) and echo-planar imaging (EPI)-DWI of the orofacial region and prove the usefulness of TSE-DWI for the differential diagnosis of orofacial lesions.Materials and methodsThe DR, SNR, and CNR of both sequences were compared in 42 cases. Then, the apparent diffusion coefficient (ADC) of various orofacial lesions obtained by TSE-DWI was investigated in 143 lesions.ResultsIn the first study, 38 of 42 cases were analyzed. TSE-DWI showed a significantly lower DR (p < 0.05) and higher SNR and CNR than EPI-DWI (p < 0.05), indicating the superiority of TSE-DWI. In the second study, 114 cases (79.3%) were successfully analyzed. When lesions were divided into cysts, benign tumors, squamous cell carcinoma, malignant lymphoma, and other malignant tumors (OT), significant differences were observed in all pairs of lesions (p < 0.05) except squamous cell carcinoma and OT (p = 0.877). The area under the curve for distinguishing benign from malignant tumors was 0.80 with a cutoff ADC of 1.29 × 10-3 mm²/s.ConclusionTSE-DWI produced better quality images than EPI-DWI. TSE-DWI yields the high possibility of obtaining ADC in the orofacial region, and this value was considered useful for the differential diagnosis of orofacial lesions.
  • The Relationship of Arterial Wall Enhancement Ratio on MRI with the Degree
           of Inflammation in a Rabbit Aneurysm Model: A Pilot Study
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Guang-xian Wang, Chao Xia, Jian Liu, Chun Cui, Sheng Lei, Ming-fu Gong, Li Wen, Dong ZhangRationale and ObjectivesTo identify the relationship between enhancement ratio (ER) of aneurysm walls and degrees of inflammation.Materials and MethodsTwenty-five white rabbits were used in this study; all underwent surgery to isolate the right common carotid artery (RCCA). Twenty rabbits underwent an aneurysm creation procedure, and 5 underwent a control procedure. In the aneurysm creation procedure, there was surgical exposure of the origin of RCCA and temporary occlusion with an aneurysm clip. The distal RCCA was ligated, and the trapped segment was infused with elastase for 20 minutes, after which the clip was removed. In the control procedure, the trapped segment was infused with saline. High-resolution magnetic resonance imaging was performed at weeks 2, 3, 4, and 5 after the procedure, and wall ER was calculated. After MRI, aneurysms were harvested and stained with hematoxylin-eosin. Pearson correlation analysis and scatter plots were used to evaluate the relationship between wall ER and the degree of inflammation. The relationships between the wall ER, the number of inflammatory cells and time were analyzed by linear graphs.ResultsWall ER positively correlated with inflammatory cell count of the aneurysm wall (r = 0.877, p < 0.001). The relationships between wall ER, the number of inflammatory cells, and time increased and then decreased according linear graphs.ConclusionIn this study, the aneurysm wall ER was confirmed to be associated with the degree of inflammation on the rabbit aneurysm model.
  • Gadoterate Meglumine Administration in Multiple Sclerosis has no Effect on
           the Dentate Nucleus and the Globus Pallidus Signal Intensities
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Salem Hannoun, Rayane Issa, Nabil K. El Ayoubi, Ribal Haddad, Marwa Baalbaki, Bassem I. Yamout, Samia J. Khoury, Roula HouraniRationale and objectivesPrevious studies on possible accumulation of gadolinium-based contrast agents (GBCA) in the brain suggest that macrocyclic GBCA are less likely to accumulate than linear GBCA. However, conflicting results have been reported, especially in MS. The aim of this study is to investigate retrospectively the correlation between gadoterate-meglumine (macrocyclic GBCA) use and T1 signal intensity changes (SI) in the dentate nucleus and the GP on unenhanced T1-weighted images in a large cohort of MS patients.Materials and methodsUnenhanced T1-weighted images of 232 MS patients who previously received multiple intravenous administrations of 0.1 mmol/kg of gadoterate-meglumine were reviewed. The change in T1 SI ratios of dentate nucleus/central pons (DN/CP) and globus pallidus/centrum semiovale (GP/CSO) was calculated between the first and last MRIs and correlated with age, number of injections, time interval between MRIs, disease duration, activity, and therapy.ResultsDN/CP ratio showed no significant changes whereas the GP/CSO ratio showed a significant decrease (p < 0.0001) between the first and last MRIs. Multivariable analyses of both ratios, controlling for age, disease duration, and time interval between MRIs, showed no significant correlation between the number of gadolinium injections and the differences in DN/CP (standardized beta = −0.018, p = 0.811) or GP/CSO SI ratios (standardized beta = −0.049, p = 0.499).ConclusionRepeated administration of gadoterate-meglumine in MS patients did not result in increased T1 SI in the DN or the GP. The significant decrease of GP/CSO ratio between the first and last MRIs is not due to gadolinium accumulation but rather to varying MR parameters.
  • Detection of Extraprostatic Extension of Cancer on Biparametric MRI
           Combining Texture Analysis and Machine Learning: Preliminary Results
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Arnaldo Stanzione, Renato Cuocolo, Sirio Cocozza, Valeria Romeo, Francesco Persico, Ferdinando Fusco, Nicola Longo, Arturo Brunetti, Massimo ImbriacoRationale and ObjectivesExtraprostatic extension of disease (EPE) has a major role in risk stratification of prostate cancer patients. Currently, pretreatment local staging is performed with MRI, while the gold standard is represented by histopathological analysis after radical prostatectomy. Texture analysis (TA) is a quantitative postprocessing method for data extraction, while machine learning (ML) employs artificial intelligence algorithms for data classification. Purpose of this study was to assess whether ML algorithms could predict histopathological EPE using TA features extracted from unenhanced MR images.Materials and MethodsIndex lesions from biparametric MRI examinations of 39 patients with prostate cancer who underwent radical prostatectomy were manually segmented on both T2-weighted images and ADC maps for TA data extraction. Combinations of different feature selection methods and ML classifiers were tested, and their performance was compared to a baseline accuracy reference.ResultsThe classifier showing the best performance was the Bayesian Network, using the dataset obtained by the Subset Evaluator feature selection method. It showed a percentage of correctly classified instances of 82%, an area under the curve of 0.88, a weighted true positive rate of 0.82 and a weighted true negative rate of 0.80.ConclusionA combined ML and TA approach appears as a feasible tool to predict histopathological EPE on biparametric MR images.
  • Performance of Diffusion Kurtosis Imaging Versus Diffusion Tensor Imaging
           in Discriminating Between Benign Tissue, Low and High Gleason Grade
           Prostate Cancer
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Maria Giovanna Di Trani, Marco Nezzo, Alessandra S. Caporale, Riccardo De Feo, Roberto Miano, Alessandro Mauriello, Pierluigi Bove, Guglielmo Manenti, Silvia CapuaniRationale and ObjectivesTo investigate the performance of diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) in discriminating benign tissue, low- and high-grade prostate adenocarcinoma (PCa).Materials and MethodsForty-eight patients with biopsy-proven PCa of different Gleason grade (GG), who provided written informed consent, were enrolled. All subjects underwent 3T DWI examinations by using b values 0, 500, 1000, 1500, 2000, and 2500 s/mm2 and six gradient directions. Mean diffusivity, fractional anisotropy (FA), apparent kurtosis (K), apparent kurtosis-derived diffusivity (D), and proxy fractional kurtosis anisotropy (KFA) maps were obtained. Regions of interest were selected in PCa, in the contralateral benign zone, and in the peritumoral area. Histogram analysis was performed by measuring mean, 10th, 25th, and 90th (p90) percentile of the whole-lesion volume. Kruskal–Wallis test with Bonferroni correction was used to assess significant differences between different regions of interest. The correlation between diffusion metrics and GG and between DKI and DTI parameters was evaluated with Pearson's test. ROC curve analysis was carried out to analyze the ability of histogram variables to differentiate low- and high-GG PCa.ResultsAll metrics significantly discriminated PCa from benign and from peritumoral tissue (except for K, KFAp90, and FA). Kp90 showed the highest correlation with GG and the best diagnostic ability (area under the curve = 0.84) in discriminating low- from high-risk PCa.ConclusionCompared to DTI, DKI provides complementary and additional information about prostate cancer tissue, resulting more sensitive to PCa-derived modifications and more accurate in discriminating low- and high-risk PCa.
  • The Application of a New Model-Based Iterative Reconstruction in Low-Dose
           Upper Abdominal CT
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Yongjun Jia, Bingying Zhai, Taiping He, Yong Yu, Nan Yu, Haifeng Duan, Chuangbo Yang, Xirong ZhangRationale and ObjectivesTo compare upper abdominal computed tomography (CT) image quality of new model-based iterative reconstruction (MBIR) with low-contrast resolution preference (MBIRNR40), conventional MBIR (MBIRc), and adaptive statistical iterative reconstruction (ASIR) at low dose with ASIR at routine-dose.Materials and MethodsStudy included phantom and 60 patients who had initial and follow-up CT scans. For patients, the delay phase was acquired at routine-dose (noise index = 10 HU) for the initial scan and low dose (noise index = 20 HU) for the follow-up. The low-dose CT was reconstructed with 40% and 60% ASIR, MBIRc, and MBIRNR40, while routine-dose CT was reconstructed with 40% ASIR. CT value and noise measurements of the subcutaneous fat, back muscle, liver, and spleen parenchyma were compared using one-way ANOVA. Two radiologists used semiquantitative 7-scale (−3 to +3) to rate image quality and artifacts.ResultsThe phantom study revealed superior low-contrast resolution with MBIRNR40. For patient scans, the CT dose index for the low-dose CT was 3.00 ± 1.32 mGy, 75% lower than the 11.90 ± 4.75 mGy for the routine-dose CT. Image noise for the low-dose MBIRNR40 images was significantly lower than the low-dose MBIRc and ASIR images, and routine-dose ASIR images (p < 0.05). Subjective ratings showed higher image quality for low-dose MBIRNR40, with lower noise, better low-contrast resolution for abdominal structures, and finer lesion contours than those of low-dose MBIRc and ASIR images, and routine-dose ASIR images (p < 0.05).ConclusionMBIRNR40 with low-contrast resolution preference provides significantly lower noise and better image quality than MBIRc and ASIR in low-dose abdominal CT; significantly better objective and subjective image quality than the routine-dose ASIR with 75% dose reduction.
  • Impact of the Intima Dynamic Motion in Type B Acute Aortic Dissection on
           Renal Injury: Quantificationally Assessed by Dose-Regulated Retrospective
           ECG-Gated Dual-Source CT Angiography
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Shuo Zhao, Hui Gu, Yanhua Duan, Zhaoping Cheng, Baojin Chen, Shifeng Yang, Ximing WangBackgroundLittle is known about the influence of intima dynamic motion on organ ischemia and related outcomes. The purpose of this study is to quantitatively evaluate intima oscillation by CT angiography (CTA), determine its impact on acute kidney injury (AKI) in patients with type B acute aortic dissection (TB-AAD) before thoracic endovascular aortic repair (TEVAR), and further analyze its association with early adverse events postoperatively.MethodsTotally, 108 patients with TB-AAD who underwent retrospective ECG-gated CTA and received TEVAR were enrolled. Patients were divided into AKI and non-AKI groups. Area of the true lumen (TLA) was computed at R–R intervals at the upper level of kidney vessel origin every 5% step from 0% to 95%. Additionally, other morphologic parameters that have been identified as risk predictors for adverse events in uncomplicated TB-AAD were evaluated.ResultsForty-three (39.8%) patients were sorted into the AKI group. Patients with AKI exhibited a larger value for the relative change of TLA (Crel-TLA) than patients in the non-AKI group (p < 0.001), as well as a larger maximum diameter of the descending aorta (p = 0.023) and the primary entry tear (p = 0.012). Crel-TLA and elevated systolic blood pressure were independent predictors of AKI. Patients with Crel-TLA ≥ 42.6% were associated with a high incidence of renal ischemia before TEVAR and early adverse events postoperatively (all p < 0.001).ConclusionIntima dynamic motion, as quantitatively evaluated by CTA, has a significant influence on renal injury before and after the aortic intervention, as well as other adverse events, which might guide clinical therapy in high-risk patients.
  • Comparison of Nongated Chest CT and Dedicated Calcium Scoring CT for
           Coronary Calcium Quantification Using a 256-Dector Row CT Scanner
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Yuhuan Chen, Zhijun Hu, Michelle Li, Yongjun Jia, Taiping He, Zhentang Liu, Donghong Wei, Yong YuBackgroundCoronary artery calcification (CAC) is a marker of atherosclerosis and an independent risk factor for cardiac-related mortality and frequently detected on noncontrast chest CT. We aimed to investigate the reliability and accuracy of determining CAC using noncontrast, nongated chest CT with 256-detector row.Materials and MethodsA total of 1318 patients for chest examination were enrolled to undergo both nongated chest CT and dedicated calcium-scoring CT (CSCT) on a 256-detector row CT scanner. The chest CT was scanned in fast-helical mode with 8 cm collimation, 0.28 second rotation speed and pitch 0.992:1 to cover entire chest. CSCT used single prospective ECG-triggered cardiac axial mode with 0.28 second rotation speed covering only the heart. CAC scores (Agatston, mass, and volume) were determined using both image sets and were statistically compared.ResultsSensitivity and specificity of nongated chest CT for determining positive CAC was 94.8% (182/192) and 100%, respectively. The agreement in assessing the quantitative Agatston, volume, and mass scores between the nongated chest CT and CSCT was almost perfect, with the intraclass correlation coefficient values of 0.998, 0.999, and 0.999, respectively. Additionally, there was a good agreement in CAC quantification between the nongated chest CT and dedicated CSCT with small coefficient of variation: mass score (9.0%), volume score (9.5%), and Agatston score (12.6%).ConclusionNongated chest CT with 256-detector row is a reliable imaging mode for detecting and quantifying calcifications in coronary arteries compared with dedicated calcium-scoring CT.
  • Detection of Pulmonary Embolism Based on Reduced Changes in Radiographic
           Lung Density During Cardiac Beating Using Dynamic Flat-panel Detector: An
           Animal-based Study
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Rie Tanaka, Tohru Tani, Norihisa Nitta, Takahisa Tabata, Noritsugu Matsutani, Shintaro Muraoka, Tsutomu Yoneyama, Shigeru SanadaRationale and ObjectivesTo assess the capacity of dynamic flat-panel detector imaging without the use of contrast media to detect pulmonary embolism (PE) based on temporal changes in radiographic lung density during cardiac beating.Materials and MethodsSequential chest radiographs of six pigs were acquired using a dynamic flat-panel detector system. A porcine model of PE was developed, and temporal changes in pixel values in the imaged lungs were analyzed during a whole cardiac cycle. Mean differences in temporal changes in pixel values between affected and unaffected lobes were assessed using the paired t test. To facilitate visual evaluation, temporal changes in pixel values were depicted using a colorimetric scale and were compared to the findings of contrast-enhanced images.ResultsAffected lobes exhibited a mean reduction of 49.6% in temporal changes in pixel values compared to unaffected lobes within the same animals, and a mean reduction of 41.3% compared to that before vessel blockage in the same lobe. All unaffected lobes exhibited significantly-increased changes in pixel values after vessel blockage (p < 0.01). In all PE models, there were color-deficient areas with shapes and locations that matched well with the perfusion defects confirmed in the corresponding contrast-enhanced images.ConclusionDynamic chest radiography enables the detection of perfusion defects in the lobe unit based on temporal changes in image density, even without the use of contrast media. Quantification and visualization techniques provide a better understanding of the circulation-induced changes depicted in dynamic chest radiographs.
  • Development and Validation of a MRI-Based Radiomics Prognostic Classifier
           in Patients with Primary Glioblastoma Multiforme
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Xin Chen, Mengjie Fang, Di Dong, Lingling Liu, Xiangdong Xu, Xinhua Wei, Xinqing Jiang, Lei Qin, Zaiyi LiuRationale and ObjectivesGlioblastoma multiforme (GBM) is the most common and deadly type of primary malignant tumor of the central nervous system. Accurate risk stratification is vital for a more personalized approach in GBM management. The purpose of this study is to develop and validate a MRI-based prognostic quantitative radiomics classifier in patients with newly diagnosed GBM and to evaluate whether the classifier allows stratification with improved accuracy over the clinical and qualitative imaging features risk models.MethodsClinical and MR imaging data of 127 GBM patients were obtained from the Cancer Genome Atlas and the Cancer Imaging Archive. Regions of interest corresponding to high signal intensity portions of tumor were drawn on postcontrast T1-weighted imaging (post-T1WI) on the 127 patients (allocated in a 2:1 ratio into a training [n = 85] or validation [n = 42] set), then 3824 radiomics features per patient were extracted. The dimension of these radiomics features were reduced using the minimum redundancy maximum relevance algorithm, then Cox proportional hazard regression model was used to build a radiomics classifier for predicting overall survival (OS). The value of the radiomics classifier beyond clinical (gender, age, Karnofsky performance status, radiation therapy, chemotherapy, and type of resection) and VASARI features for OS was assessed with multivariate Cox proportional hazards model. Time-dependent receiver operating characteristic curve analysis was used to assess the predictive accuracy.ResultsA classifier using four post-T1WI-MRI radiomics features built on the training dataset could successfully separate GBM patients into low- or high-risk group with a significantly different OS in training (HR, 6.307 [95% CI, 3.475-11.446]; p < 0.001) and validation set (HR, 3.646 [95% CI, 1.709–7.779]; p < 0.001). The area under receiver operating characteristic curve of radiomics classifier (training, 0.799; validation, 0.815 for 12-month) was higher compared to that of the clinical risk model (Karnofsky performance status, radiation therapy; training, 0.749; validation, 0.670 for 12-month), and none of the qualitative imaging features was associated with OS. The predictive accuracy was further improved when combined the radiomics classifier with clinical data (training, 0.819; validation: 0.851 for 12-month).ConclusionA classifier using radiomics features allows preoperative prediction of survival and risk stratification of patients with GBM, and it shows improved performance compared to that of clinical and qualitative imaging features models.
  • Lung Cancer Screening with Low-Dose CT: Baseline Screening Results in
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Li Fan, Yun Wang, Ying Zhou, Qiong Li, Wenjie Yang, Shengping Wang, Fei Shan, Xingwei Zhang, Jingyun Shi, Wufei Chen, Shi-Yuan LiuObjectiveTo report the initial baseline lung cancer screening results with low dose computed tomography (LDCT) in a multicenter study in Shanghai.MethodsA total of 14,506 subjects underwent LDCT lung cancer screening and completed questionnaires consisting of 13 risk factors for lung cancer in the prospective study. The positive result was defined as any size and density nodule. The nodules were classified into calcified, solid, part-solid, and nonsolid nodules. The positive rate and incidental detection rate of lung cancer and stage I lung cancer were calculated. The proportion of lung nodule and lung cancer with different density and size was analyzed.ResultsThe positive rate and incidental detection rate of lung cancer was 29.89% and 1.23%, respectively. The incidental detection rate of stage I lung cancer was 0.97%. The proportion of lung cancer in lung nodules and stage I in lung cancer was 3.48% and 81.09%, respectively. The ratio of nonsolid nodule, part-solid nodule, and solid nodule in lung cancer was 52.94%, 31.93%, and 15.13%, respectively. 74.88% lung nodules were less than 5 mm and 94.12% lung cancers were larger than 5mm in size.ConclusionThe baseline LDCT lung cancer screening showed subsolid nodules accounted for the majority of lung cancer, and 5 mm in size would be recommended as the positive result threshold.
  • Life Imitates Art
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): N. Reed Dunnick
  • The Power of Design Thinking in Medical Education
    • Abstract: Publication date: October 2019Source: Academic Radiology, Volume 26, Issue 10Author(s): Lori A. Deitte, Reed A. OmaryA goal of medical education should be to optimize educational experiences of our learners. How can we better understand their experiences and design educational activities that inspire them to learn' Design Thinking is a powerful process that consists of five iterative phases: empathize, define, ideate, prototype, and test. Empathy with the user experience is at the core of Design Thinking. This helps define the right problem so that the right solutions can be developed. In this article, we share our experiences with using Design Thinking in radiology education. As educators, we are constantly learning and innovating. Design Thinking provides a powerful process and a growth mindset to help develop creative solutions as we move forward. We invite you to join us in this discovery quest for innovative solutions in medical education through the Design Thinking process.
  • Recruiting Future Radiologists: How Can We Do Better'
    • Abstract: Publication date: Available online 11 September 2019Source: Academic RadiologyAuthor(s): Kara Gaetke-Udager, Donna Magid, Mathew Smith, Vishal Kumar, Minhajuddin Khaja, N. Reed Dunnick
  • Differential Diagnosis of Nonhypervascular Pancreatic Neuroendocrine
           Neoplasms From Pancreatic Ductal Adenocarcinomas, Based on Computed
           Tomography Radiological Features and Texture Analysis
    • Abstract: Publication date: Available online 5 September 2019Source: Academic RadiologyAuthor(s): Haopeng Yu, Zixing Huang, Mou Li, Yi Wei, Lin Zhang, Chengmin Yang, Yongchang Zhang, Bin SongRationale and ObjectivesTo determine computed tomography (CT) radiological features and texture features that are rewarding in differentiating nonhypervascular pancreatic neuroendocrine neoplasms (PNENs) from pancreatic ductal adenocarcinomas (PDACs).Materials and MethodsWe compared patients to pathologically proven nonhypervascular PNENs and age-matched controls with pathologically proven PDACs in a 1:2 ratio. Preoperative CT images in the arterial phase (AP) and portal vein phase (PVP) were obtained. Two radiologists independently reviewed the morphological characteristics of each tumor. Three-dimensional regions of interest (ROIs), drawn using ITK-SNAP software, were input into AK software (Artificial Intelligent Kit, GE) to extract texture features from AP and PVP images. Differences between PNENs and PDACs were analyzed with the chi-squared test, least absolute shrinkage and selection operator, kappa statistics, and uni- and multivariate logistic regression analyses.ResultsIn total, 40 nonhypervascular PNENs and 80 PDACs were evaluated. Maximum diameter on axial section, margin, calcification, vascularity in the tumor, and tumor heterogeneity were significantly different between PDACs and nonhypervascular PNENs. Multivariate analysis showed well-defined tumor margin (odds ratio: 21.0) and presence of calcification (odds ratio: 4.4) were significant predictors of nonhypervascular PNENs. The area under the receiver operating characteristic curve of the radiological feature model, AP texture model, and PVP texture model were 0.780, 0.855, and 0.929, respectively, based on logistic regression.ConclusionA well-defined margin and calcification in the tumor were helpful in discriminating nonhypervascular PNENs from PDACs. Texture analysis of contrast-enhanced CT images could be beneficial in differentially diagnosing nonhypervascular PNENs and PDACs.
  • Contrast Enhanced Digital Mammography (CEDM) Helps to Safely Reduce Benign
           Breast Biopsies for Low to Moderately Suspicious Soft Tissue Lesions
    • Abstract: Publication date: Available online 5 September 2019Source: Academic RadiologyAuthor(s): Margarita L. Zuley, Andriy I. Bandos, Gordon S. Abrams, Marie A. Ganott, Terri-Ann Gizienski, Christiane M. Hakim, Amy E. Kelly, Bronwyn E. Nair, Jules H. Sumkin, Uzma Waheed, David GurRationale and ObjectivesTo preliminarily asses if Contrast Enhanced Digital Mammography (CEDM) can accurately reduce biopsy rates for soft tissue BI-RADS 4A or 4B lesions.Materials and MethodsEight radiologists retrospectively and independently reviewed 60 lesions in 54 consenting patients who underwent CEDM under Health Insurance Portability and Accountability Act compliant institutional review board-approved protocols. Readers provided Breast Imaging Reporting & Data System ratings sequentially for digital mammography/digital breast tomosynthesis (DM/DBT), then with United States, then with CEDM for each lesion. Area under the curve (AUC), true positive rates and false positive rates, positive predictive values and negative predictive values were calculated. Statistical analysis accounting for correlation between lesion-examinations and between-reader variability was performed using OR/DBM (for SAS v.3.0), generalized linear mixed model for binary data (proc glimmix, SAS v.9.4, SAS Institute, Cary North Carolina), and bootstrap.ResultsThe cohort included 49 benign, two high-risk and nine cancerous lesions in 54 women aged 34–74 (average 50) years. Reader-averaged AUC for CEDM was significantly higher than DM/DBT alone (0.85 versus 0.66, p < 0.001) or with US (0.85 versus 0.75, p = 0.001). CEDM increased true positive rates from 0.74 under DB/DBT, and 0.89 with US, to 0.90 with CEDM, (p = 0.019 DM/DBT versus CEDM, p = 0.78 DM/DBT + US versus CEDM) and decreased false positive rates from 0.47 using DM/DBT and 0.61 with US to 0.39 with CEDM (p = 0.017 DM/DBT versus CEDM, p = 0.001 DM/DBT+ US versus CEDM). For an expected cancer rate of 10%, CEDM positive predictive values was 20.5% (95% CI: 16%–27%) and negative predictive values 98.3% (95% CI: 96%–100%).ConclusionAddition of CEDM for evaluation of low-moderate suspicion soft tissue breast lesions can substantially reduce biopsy of benign lesions without compromising cancer detection.
  • Preoperative Ultrasound Radiomics Signatures for Noninvasive Evaluation of
           Biological Characteristics of Intrahepatic Cholangiocarcinoma
    • Abstract: Publication date: Available online 5 September 2019Source: Academic RadiologyAuthor(s): Yu-ting Peng, Chuan-yang Zhou, Peng Lin, Dong-yue Wen, Xiao-dong Wang, Xiao-zhu Zhong, Deng-hua Pan, Qiao Que, Xin Li, Ling Chen, Yun He, Hong YangRationale and ObjectivesThe purpose of this study was to establish and validate radiomics signatures based on ultrasound (US) medicine images to assess the biological behaviors of intrahepatic cholangiocarcinoma (ICC) in a noninvasive manner.Materials and MethodsThis study consisted of 128 ICC patients. We focused on evaluating six pathological features: microvascular invasion, perineural invasion, differentiation, Ki-67, vascular endothelial growth factor, and cytokeratin 7. Region of interest (ROI) of ICC was identified by manually plotting the tumor contour on the grayscale US image. We extracted radiomics features from medical US imaging. Then, dimensionality reduction methods and classifiers were used to develop radiomic signatures for evaluating six pathological features in ICC. Finally, independent validation datasets were used to assess the radiomic signatures performance.ResultsWe extracted 1076 quantitative characteristic parameters on the US medicine images. Based on extracted radiomics features, the best performing radiomic signatures for evaluating microvascular invasion features were produced by hypothetical test + support vector machine (SVM), perineural invasion subgroup were least absolute shrinkage and selection operator + principal component analysis + support vector machine, differentiation subgroup were hypothetical test + decision tree, Ki-67 subgroup were hypothetical test + logistic regression, vascular endothelial growth factor subgroup were hypothetical test + Gradient Boosting Decision Tree (GBDT), and cytokeratin 7 subgroup were hypothetical test + bagging, respectively.ConclusionThrough the high-throughput radiomics analysis based on US medicine images, we proposed radiomics signatures that have moderate efficiency in predicting the biological behaviors of ICC noninvasively.
  • Two-dimensional Shear Wave Elastography with Propagation Maps for the
           Assessment of Liver Fibrosis and Clinically Significant Portal
           Hypertension in Patients with Chronic Liver Disease: A Prospective Study
    • Abstract: Publication date: Available online 4 September 2019Source: Academic RadiologyAuthor(s): Sun Kyung Jeon, Jeong Min Lee, Ijin Joo, Jeong Hee Yoon, Dong Ho Lee, Joon Koo HanObjectivesTo investigate the diagnostic performance of liver stiffness (LS) measurements on two-dimensional (2D) shear wave elastography (SWE) for the assessment of hepatic fibrosis using LS measurements on MR elastography (MRE) as the reference standard and the prediction of clinically significant portal hypertension (CSPH).MethodsIn this prospective study, 101 patients with chronic liver disease or cirrhosis underwent both MRE and SWE. After exclusion of technical failure on MRE (n = 5), technical failure/unreliable measurement on SWE (n = 4), LS measurements obtained on SWE with the aid of propagation maps were correlated with those of the MRE using Pearson's correlation analysis. Diagnostic performances for significant fibrosis (≥F2: MRE of ≥2.99 kPa) or cirrhosis (F4: MRE of ≥3.63 kPa) and for the prediction of CSPH were assessed using receiver operating characteristics (ROC) curve analysis.ResultsLS values on SWE showed a strong correlation with those on MRE (r = 0.846, P < 0.001). For the diagnosis of significant fibrosis or cirrhosis in patients with hepatitis B virus-related liver disease (n = 75), SWE showed areas under the ROC curves (AUC) of 0.975 and 0.912, respectively (95% confidence interval [CI], 0.910–997, and 0.824–0.965). For the prediction of CSPH, the AUC of SWE was 0.818 (95% CI, 0.712–0.898), and when an LS value of 11.5 kPa was applied as a cut-off, SWE showed a sensitivity of 81.5% and a specificity of 72.9%.ConclusionLS measurements on 2D SWE were demonstrated to be well correlated with those obtained with MRE, and thus, may provide good diagnostic performance for the prediction of hepatic fibrosis and the presence of CSPH.
  • CT Boost, an Important Step in Endoleak Diagnosis
    • Abstract: Publication date: Available online 4 September 2019Source: Academic RadiologyAuthor(s): Erica B. Stein, David M. Williams
  • Varicocele Embolization: An assessment of the Quality and Readability of
           Online Patient Information
    • Abstract: Publication date: Available online 4 September 2019Source: Academic RadiologyAuthor(s): J.H. Alderson, D.C. O'Neil, C.E. Redmond, D Mulholland, M.J. LeeAims and ObjectivesVaricocele embolization is a growing treatment modality owing to the safety, efficacy, and quick return to work following the procedure. The internet is the most dominant source of information for many. We aimed to assess the quality of information accessible by patients considering treatment.Materials and MethodsA list of applicable, commonly used searchable terms was generated. Each term was assessed across the five most-used English language search engines to determine the two most commonly used terms. These two terms were then investigated across each search engine, with the first 25 web pages returned by each engine included for analysis. Duplicate web pages, nontext content such as video or audio, and web pages behind paywalls were excluded. Web pages were analyzed for quality and readability using validated tools including DISCERN score, JAMA Benchmark Criteria, HONcode Certification, Flesch Reading Ease Score, Flesch–Kincaid Grade Level, and Gunning–Fog Index. Secondary features including age, rank, author, and publisher were recorded.ResultsThe most common applicable terms were “Testicular embolization” (378,300 results) and “Varicocele embolization” (375,800 results). Mean DISCERN quality of information provided by websites is “fair”; Adherence to JAMA Benchmark Criteria was 13.5%. Flesh–Kincaid readability tests demonstrated an average “9th grade” reading level. Scientific journals showed the highest quality scores, but were least up to date with an average web page age of 11.2 years. Web pages produced by “for-profit” organizations were the second most current (average age 2.7 years), but displayed the lowest quality of information scores.ConclusionWhile quality of online information available to patients is “fair,” adherence to JAMA benchmark criteria is poor. “For-profit” organization websites are far more numerous and significantly more up-to-date, yet showed significantly lower quality of information scores. Scientific journals were unsurprisingly of higher quality, yet more challenging for the general public to read. These findings call for the production of high-quality and comprehensible content regarding interventional radiology, where physicians can reliably direct their patients for information.
  • The Use of a Student Radiology Interest Group to Promote Ultrasound
           Education–A Single Center Experience
    • Abstract: Publication date: Available online 3 September 2019Source: Academic RadiologyAuthor(s): V Linehan, J Ramlackhansingh, A Hartery, R GullipalliRational and ObjectivesDespite the increasing use of point of care ultrasound (POCUS) across many specialities, ultrasound training in Canadian medical schools is limited. At our center, the student Radiology Interest Group (RIG) has addressed this learning need by hosting an annual workshop for diagnostic ultrasound to improve student competency in POCUS.Materials and MethodsThe Ultrasound Workshop is a voluntary event offered to second-year medical students by the RIG. Feedback from each session is collected to continually improve the workshop and inform on teaching strategies. This year, we also provided an online survey to all second-year medical students that compared the competency and confidence of students who did or did not attend the workshop.ResultsStudent feedback from the Ultrasound Workshop was extremely positive. Students believed it was a valuable training experience and should be incorporated into the curriculum. The Ultrasound Workshop increased student's basic understanding of ultrasound but did not affect their confidence in using POCUS compared to students who did not attend. Finally, results from the online survey demonstrated that students believe learning POCUS is necessary for their future career, but there is not enough training in the current curriculum.ConclusionThe Ultrasound Workshop is a useful training exercise to increase student understanding of ultrasound, but more training may be required to increase student confidence and competency. Overall, extracurricular Ultrasound Workshops coordinated by student-led RIGs can serve as successful adjuncts to the curriculum.
  • Radiology Journal Club for Medical Students
    • Abstract: Publication date: Available online 2 September 2019Source: Academic RadiologyAuthor(s): Tushar Garg, Apurva Shrigiriwar
  • Chest X-ray Dose Equivalent Low-dose CT with Tin Filtration: Potential
           Role for the Assessment of Pectus Excavatum
    • Abstract: Publication date: Available online 28 August 2019Source: Academic RadiologyAuthor(s): Olivia Messerli-Odermatt, Bettina Serrallach, Manuel Gubser, Sebastian Leschka, Ralf W. Bauer, Josée Dubois, Hatem Alkadhi, Simon Wildermuth, Stephan L. WaeltiRationale and ObjectivesTo determine the value of chest CT with tin filtration applying a dose equivalent to chest x-ray for the assessment of the Haller index for evaluation of pectus excavatum.Materials and MethodsTwo hundred seventy-two patients from a prospective single center study were included and underwent a clinical standard dose chest CT (effective dose 1.8 ± 0.7 mSv) followed by a low-dose CT (0.13 ± 0.01 mSv) in the same session. Two blinded readers independently evaluated all data sets. Image quality for bony chest wall assessment was noted. Radiologists further assessed (a) transverse thoracic diameter, (b) anteroposterior thoracic diameter, and calculated (c) Haller index by dividing transverse diameter by anteroposterior diameter. The agreement of both readers in standard dose and low-dose CT was assessed using Lin's concordance correlation coefficient (pc).ResultsSubjective image quality was lower for low dose compared to standard dose CT images by both readers (p < 0.001). In total, 99% (n = 540) of low-dose CT scans were rated as diagnostic for bony chest wall assessment by both readers. There was a high agreement for assessment of transverse diameter, anteroposterior diameter and Haller index comparing both readers in standard dose and low-dose CT with pc values indicating substantial agreement (i.e., 0.95> and ≤0.99) in 12/18 (67%) and almost perfect agreement (i.e.,>0.99) in 6/18 (33%).ConclusionOur study suggests that low-dose CT with tin filtration applying a radiation dose equivalent to a plain chest X-ray is excellent for assessing the Haller index.
  • A Program Director's Guide to Cultivating Diversity and Inclusion in
           Radiology Residency Recruitment
    • Abstract: Publication date: Available online 28 August 2019Source: Academic RadiologyAuthor(s): Carolynn M. DeBenedectis, Darel E. Heitkamp, Eric England, Glenn C. Gaviola, Joshua A. Hirsch, Christopher P. Ho, Ann K. Jay, Nolan Kagetsu, Vivek Kalia, James Milburn, Seng Ong, Angelisa M. Paladin, Maitray D. Patel, Jonathan Swanson, David S. Sarkany
  • Quantitative Improvement in Brain Tumor MRI Through Structured Reporting
    • Abstract: Publication date: Available online 27 August 2019Source: Academic RadiologyAuthor(s): James Y. Zhang, Brent D. Weinberg, Ranliang Hu, Amit Saindane, Mark Mullins, Jason Allen, Michael J. HochRationale and ObjectivesDetermine the objective benefits of structured reporting of brain tumors through Brain tumor-RADS (BT-RADS) by analyzing discrete quantifiable metrics of the reports themselves.Materials and MethodsFollowing Institutional Review Board approval, post-treatment glioma reports were acquired from two matched 3-month time periods for pre- and postimplementation of BT-RADS. The reports were analyzed for presence of history words, such as “Avastin” and “methylguanine-DNA methyltransferase,” as well as hedge words, such as “Possibly” and “Likely.” The word counts of the total report and of the impression section were also assessed, as well as whether or not the report contained addenda.ResultsIn total, 211 pre-BT-RADS and 172 post-BT-RADS reports were analyzed. Post-BT-RADS reports demonstrated greater reporting of history words, including “Avastin” (7.6% vs. 20.9%, p < 0.001) and “methylguanine-DNA methyltransferase” (10.9% vs. 31.4%, p < 0.0001). They also demonstrated reduced usage of hedge words, including “Possibly” (3.8% vs. 0.6%, p < 0.05) and “Likely” (49.8% vs. 28.5%, p < 0.01). Furthermore, post-BT-RADS reports possessed fewer words in total report length (389 vs. 245.2, p < 0.001), as well as in the impression section (53.7 vs. 42.6, p < 0.01). Finally, fewer post-BT-RADS reports contained addenda (10% vs. 1.2%, p < 0.01).ConclusionFollowing implementation of BT-RADS, glioma reports demonstrated greater consistency and completeness of clinical history, less ambiguity, and more conciseness.
  • Confronting the US's Highly Uneven State-by-State Distribution of
           Diagnostic Radiology Residency Positions
    • Abstract: Publication date: Available online 27 August 2019Source: Academic RadiologyAuthor(s): Mohsin Mukhtar, Korbin Davis, Aaron P. Kamer, Richard B. Gunderman
  • Ventilation Heterogeneity and Its Association with Nodule Formation Among
           Participants in the National Lung Screening Trial—A Preliminary
    • Abstract: Publication date: Available online 27 August 2019Source: Academic RadiologyAuthor(s): David A. Kaminsky, Nirav Daphtary, Raul S.J. Estepar, Taka Ashikaga, Lukas Mikulic, Jeffrey Klein, C. Matthew KinseyRationale and ObjectivesWe have developed a technique to measure ventilation heterogeneity (VH) on low dose chest CT scan that we hypothesize may be associated with the development of lung nodules, and perhaps cancer. If true, such an analysis may improve screening by identifying regional areas of higher risk.Materials and MethodsUsing the National Lung Screening Trial database, we identified a small subset of those participants who were labeled as having a positive screening test at 1 year (T1) but not at baseline (T0). We isolated the region in which the nodule would form on the T0 scan (“target region”) and measured VH as the standard deviation of the linear dimension of a virtual cubic airspace based on measurement of lung attenuation within the region.ResultsWe analyzed 24 cases, 9 with lung cancer and 15 with a benign nodule. We found that the VH of the target region was nearly statistically greater than that of the corresponding contralateral control region (0.168 [0.110–0.226] vs. 0.112 [0.083–0.203], p = 0.051). The % emphysema within the target region was greater than that of the corresponding contralateral control region (1.339 [0.264–4.367] vs. 1.092 [0.375–4.748], p = 0.037). There was a significant correlation between the % emphysema and the VH of the target region (rho = +0.437, p = 0.026).ConclusionOur study provides the first data in support of increased local VH being associated with subsequent lung nodule formation. Further work is necessary to determine whether this technique can enhance screening for lung cancer by low dose chest CT scan.
  • Use of 3D Printed Models to Create Molds for Shaping Implants for Surgical
           Repair of Orbital Fractures
    • Abstract: Publication date: Available online 27 August 2019Source: Academic RadiologyAuthor(s): William J. Weadock, Curtis J. Heisel, Alon Kahana, John KimRationale and ObjectivesSurgical repair of an isolated orbital fracture requires anatomically accurate implant shape and placement. We describe a three-dimensional (3D) printing technique to customize the shape of commercially available absorbable implants.Materials and MethodsWe reviewed our early experience with three cases in which 3D printed molds were utilized for fracture repair. The institution's medical records were reviewed to assess operative time for orbital floor blow-out fracture repairs. Thin section computed tomography (CT) images were loaded into a clinical 3D visualization software, and stereolithography models were created. The models were loaded into stereolithography editing software in which the nonfractured side was mirrored and overlaid with the fractured side. Sterilizable 3D printed molds were created using the fracture images as well as the virtual mirrored images. The molds were taken to the operating room and used to shape a customized orbital implant for fracture repair, using off-the-shelf bioabsorbable implants.ResultsThe three patients treated using 3D printed molds had excellent outcomes, with decreased postoperative edema and rapid resolution of ocular misalignment/strabismus. Surgical times were decreased from an average of 93.3 minutes using standard implants to 48.3 minutes following adoption of 3D printed molds.ConclusionThree-dimensional printed models can be used to create molds for shaping bioabsorbable implants for customized surgical repair, improving fit, reducing tissue handling and postoperative edema, and reducing surgical times.
  • Corrigendum to “What Program Directors Think IV: Results of the 2017
           Annual Survey of the Association of Program Directors in Radiology”
           [Acad Radiol 2019; 26:1102-1109]
    • Abstract: Publication date: Available online 24 August 2019Source: Academic RadiologyAuthor(s): Anna Rozenshtein, Brent Griffith, T.L. Mohammed, Darel E. Heitkamp, Linda A. Deloney, Angelisa M. Paladin, Stacy E. Smith, Ernest F. Wiggins, Jonathan O. Swanson
  • A Single Enhanced Dual-Energy CT Scan May Distinguish Lung Squamous Cell
           Carcinoma From Adenocarcinoma During the Venous phase
    • Abstract: Publication date: Available online 22 August 2019Source: Academic RadiologyAuthor(s): Zhaotao Zhang, Hongye Zou, Aimei Yuan, Fei Jiang, Baolin Zhao, Yin Liu, Jinghua Chen, Minjing Zuo, Lianggeng GongRationale and ObjectivesTo investigate whether iodine quantification extracted from enhanced dual energy-computed tomography (DE-CT) is useful for distinguishing lung squamous cell carcinoma from adenocarcinoma and to evaluate whether a single scan evaluated during the venous phase (VP) can be substituted for scans evaluated during other phases.Materials and MethodsSixty-two patients with lung cancer (32 squamous cell carcinomas; 30 adenocarcinomas) underwent enhanced dual-phase DE-CT scans, including an arterial phase and VP. The iodine concentration (IC), normalized iodine concentration (NIC), and slope of the curve (K) in lesions were measured during two scanning phases in two different pathological types of lung cancers. The differences in parameters (IC, NIC, and K) between these two types of lung cancers were statistically analyzed. In addition, the receiver operating characteristic curves of these parameters were performed to discriminate squamous cell carcinoma from adenocarcinoma.ResultsThe mean IC, NIC, and K in adenocarcinomas were all higher than those in squamous cell carcinomas during the two scanning phases. However, the differences in these parameters between the two types of cancers were significant only during the VP, not during the arterial phase. Receiver operating characteristic analysis demonstrated that the optimal thresholds of the IC, NIC, and K for discriminating squamous cell carcinoma from adenocarcinoma were 1.550, 0.227, and 1.608, respectively. In addition, the sensitivity, specificity, and area under the curve were 81.2%, 83.3%, and 0.871 for the IC; 56.2%, 93.3%, and 0.800 for the NIC; and 65.6%, 80%, and 0.720 for the K; 81.3%, 83.3%, and 0.874 for the IC + NIC; 68.8%, 93.3%, and 0.891 for the IC + NIC + K, respectively. The “IC + NIC + K” had the highest diagnostic efficiency for discriminating two types of lung cancers, but with low sensitivity. Whereas, “IC”and “IC + NIC” had the similar lower diagnostic efficiency, but with high sensitivity and specificity.ConclusionThe iodine quantification parameters derived from enhanced DE-CT during the VP may be useful for distinguishing lung squamous cell carcinoma from adenocarcinoma.
  • Correlation of Algorithmic and Visual Assessment of Lesion Detection in
           Clinical Images
    • Abstract: Publication date: Available online 22 August 2019Source: Academic RadiologyAuthor(s): Yuan Cheng, Taylor Brunton Smith, Corey T Jensen, Xinming Liu, Ehsan SameiRationale and ObjectivesClinically-relevant quantitative measures of task-based image quality play key roles in effective optimization of medical imaging systems. Conventional phantom-based measures do not adequately reflect the real-world image quality of clinical Computed Tomography (CT) series which is most relevant for diagnostic decision-making. The assessment of detectability index which incorporates measurements of essential image quality metrics on patient CT images can overcome this limitation. Our current investigation extends and validates the technique on standard-of-care clinical cases.Materials and MethodsWe obtained a clinical CT image dataset from an Institutional Review Board-approved prospective study on colorectal adenocarcinoma patients for detecting hepatic metastasis. For this study, both perceptual image quality and lesion detection performance of same-patient CT image series with standard and low dose acquisitions in the same breath hold and four processing algorithms applied to each acquisition were assessed and ranked by expert radiologists. The clinical CT image dataset was processed using the previously validated method to estimate a detectability index for each known lesion size in the size distribution of hepatic lesions relevant for the imaging task and for each slice of a CT series. We then combined these lesion-size-specific and slice-specific detectability indexes with the size distribution of hepatic lesions relevant for the imaging task to compute an effective detectability index for a clinical CT imaging condition of a patient. The assessed effective detectability indexes were used to rank task-based image quality of different imaging conditions on the same patient for all patients. We compared the assessments to those by expert radiologists in the prospective study in terms of rank order agreement between the rankings of algorithmic and visual assessment of lesion detection and perceptual quality.ResultsOur investigation indicated that algorithmic assessment of lesion detection and perceptual quality can predict observer assessment for detecting hepatic metastasis. The algorithmic and visual assessment of lesion detection and perceptual quality are strongly correlated using both the Kendall's Tau and Spearman's Rho methods (perfect agreement has value 1): for assessment of lesion detection, 95% of the patients have rank correlation coefficients values exceeding 0.87 and 0.94, respectively, and for assessment of perceptual quality, 0.85 and 0.94, respectively.ConclusionThis study used algorithmic detectability index to assess task-based image equality for detecting hepatic lesions and validated it against observer rankings on standard-of-care clinical CT cases. Our study indicates that detectability index provides a robust reflection of overall image quality for detecting hepatic lesions under clinical CT imaging conditions. This demonstrates the concept of utilizing the measure to quantitatively assess the quality of the information content that different imaging conditions can provide for the same clinical imaging task, which enables targeted optimization of clinical CT systems to minimize clinical and patient risks.
  • Reply to the USMLE Step 1 Pass/Fail Reporting Proposal: Another Opinion
    • Abstract: Publication date: Available online 22 August 2019Source: Academic RadiologyAuthor(s): J. Bryan Carmody, David S. Sarkany, Darel E. Heitkamp
  • The USMLE Step 1 Pass/Fail Reporting Proposal: Another Opinion
    • Abstract: Publication date: Available online 22 August 2019Source: Academic RadiologyAuthor(s): Absia Jabbar, Shahzaib Nabi, Khurram Shafique, Adeel Arshad
  • MRI Texture Analysis for Differentiating Nonfunctional Pancreatic
           Neuroendocrine Neoplasms From Solid Pseudopapillary Neoplasms of the
    • Abstract: Publication date: Available online 20 August 2019Source: Academic RadiologyAuthor(s): Xudong Li, Hui Zhu, Xiaohua Qian, Nan Chen, Xiaozhu LinRationale and ObjectivesTo evaluate the value of texture analysis on preoperative magnetic resonance imaging (MRI) for identifying nonfunctional pancreatic neuroendocrine neoplasms (NF-PNENs) and solid pseudopapillary neoplasms (SPNs).Materials and MethodsThis retrospective study included 119 patients who underwent MRI, including T2-weighted imaging with fat-suppression, diffusion-weighted imaging (DWI), apparent diffusion coefficient, precontrast T1-weighted imaging with fat-suppression (T1WI+fs), and dynamic contrast-enhanced (DCE)-T1WI+fs. Raw data analysis, principal component analysis, linear discriminant analysis, and nonlinear discriminant analysis (NDA) were used to classify NF-PNENs and SPNs. The results are reported as misclassification rates. The images were simultaneously evaluated by an experienced senior radiologist without knowledge of the pathological results. The misclassification rate of the radiologist was compared to the MaZda (texture analysis software) results. Neural network classifier testing was used for validation. In addition, 30 textures for each MRI sequence were investigated.ResultsThe misclassification rate of NDA was lower than that of other analyses. In NDA, DWI obtained the lowest value of 7.92%, but there was no significant difference among the sequences. The misclassification rate of the radiologist (34.65%) was significantly higher than that of NDA for all sequences. The validation results were good in the arterial phase and delayed phase. In the training set, entropy and sum entropy were optimal texture features on DWI and precontrast T1WI+fs, while the mean and percentile seemed to be the more discriminative features on DCE-T1WI+fs.ConclusionTexture analysis can sensitively distinguish between NF-PNENs and SPNs on MRI, and percentile and mean of DCE-T1WI+fs images were informative for differentiation of neoplasms.
  • Dynamic Contrast-Enhanced MRI Evaluation of Pathologic Complete Response
           in Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Breast Cancer
           After HER2-Targeted Therapy
    • Abstract: Publication date: Available online 20 August 2019Source: Academic RadiologyAuthor(s): Laura Heacock, Alana Lewin, Abimbola Ayoola, Melanie Moccaldi, James S. Babb, Sungheon G. Kim, Linda MoyRationale and ObjectivesPathologic complete response (pCR) in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer after HER2-targeted therapy correlates increased disease-free survival and decreased mastectomy rates. The aim of this study was to explore tumor shrinkage patterns and initial tumor enhancement with pCR in HER2-positive breast cancer.Materials and MethodsThis was an institutional review board-approved retrospective analysis of 51 HER2 positive breast cancer patients with breast MRI both pre- and post-HER2-targeted therapy. Initial enhancement ratio (IER, initial enhancement percentage over baseline at first postcontrast imaging), pattern of tumor shrinkage, and Dynamic contrast enhanced (DCE)-MRI imaging features were assessed. Wilcoxon rank, Spearman correlation, Fisher's exact, and Mann-Whitney tests were used to correlate MRI imaging features with pCR. IER reader agreement was evaluated by intraclass correlation. Binary logistic regression was used to evaluate multivariate associations with pCR.Results56.9% (29/51) of patients had pCR at surgery. Concentric tumor shrinkage pattern was associated with pCR (p = 0.001, Area under the curve (AUC) 0.778): accuracy 80.4%, specificity 96.6%, and sensitivity of 59.1%. There was no association with pCR and imaging response as defined by RECIST criteria (p = 0.169), pretreatment IER (Reader 1 (R1) p = 0.665, Reader 2 (R2) p = 0.766), or lesion size (p = 0.69). IER was associated with axillary metastases (R1 p = 0.016, R2 < 0.001) and ki-67 (R1 r = 0.52, p = 0.008, R2 r = −0.44, p = 0.028).ConclusionThe shrinkage pattern of HER2-positive tumors after targeted therapy may be associated with pCR. There was no association between IER and pCR. Future studies evaluating the correlation of shrinkage patterns to texture radiomics are of interest.
  • Diagnostic Accuracy of Noncontrast Self-navigated Free-Breathing MR
           Angiography Versus CT Angiography: A Prospective Study in Pediatric
           Patients with Suspected Anomalous Coronary Arteries
    • Abstract: Publication date: Available online 19 August 2019Source: Academic RadiologyAuthor(s): Maryam Ghadimi Mahani
  • Parents of Pediatric Radiology Patients Prefer Timely Reporting and
           Discussing Results with Referring Providers
    • Abstract: Publication date: Available online 14 August 2019Source: Academic RadiologyAuthor(s): Emily A. Edwards, Andre Cote, Andrew S. Phelps, David M. NaegerRationale and ObjectivesWith the introduction of new communication channels, such as encrypted messaging and online electronic medical record patient portals, there are ever-increasing ways for patients and their families to access their medical information. While patient preferences regarding how they receive the results of their radiology examinations have been assessed in the adult population, there is limited data on parent preferences for pediatric radiology patients.Materials and MethodsThe aim of this study was to determine how the parents of pediatric radiology patients prefer to receive the results of their child's imaging studies. The study design was an institutional review board-approved anonymous voluntary survey distributed to parents in a pediatric radiology waiting room.ResultsOf the current possible ways to receive radiology results, most parents preferred to receive their child's radiology results from the referring doctor (65%). A minority of parents preferred to receive the results from a radiologist in-person (16%) or via the radiology report (16%). In multiple hypothetical scenarios, parents also preferred to receive radiology results from the referring doctor rather than the radiologist, with the single exception being when no subsequent appointment with the referring doctor was planned. When asked to prioritize the most important aspect of receiving radiology test results, most parents prefer having results available quickly (65%).ConclusionThis survey suggests that in the pediatric radiology realm, efforts toward timely reporting will likely have a greater impact on patient satisfaction than prioritizing more in-person radiologist-patient communication.
  • Educating Learners about the Pros and Cons of Telework
    • Abstract: Publication date: Available online 14 August 2019Source: Academic RadiologyAuthor(s):
  • Automated Segmentation of Tissues Using CT and MRI: A Systematic Review
    • Abstract: Publication date: Available online 10 August 2019Source: Academic RadiologyAuthor(s): Leon Lenchik, Laura Heacock, Ashley A. Weaver, Robert D. Boutin, Tessa S. Cook, Jason Itri, Christopher G. Filippi, Rao P. Gullapalli, James Lee, Marianna Zagurovskaya, Tara Retson, Kendra Godwin, Joey Nicholson, Ponnada A. NarayanaRationale and ObjectivesThe automated segmentation of organs and tissues throughout the body using computed tomography and magnetic resonance imaging has been rapidly increasing. Research into many medical conditions has benefited greatly from these approaches by allowing the development of more rapid and reproducible quantitative imaging markers. These markers have been used to help diagnose disease, determine prognosis, select patients for therapy, and follow responses to therapy. Because some of these tools are now transitioning from research environments to clinical practice, it is important for radiologists to become familiar with various methods used for automated segmentation.Materials and MethodsThe Radiology Research Alliance of the Association of University Radiologists convened an Automated Segmentation Task Force to conduct a systematic review of the peer-reviewed literature on this topic.ResultsThe systematic review presented here includes 408 studies and discusses various approaches to automated segmentation using computed tomography and magnetic resonance imaging for neurologic, thoracic, abdominal, musculoskeletal, and breast imaging applications.ConclusionThese insights should help prepare radiologists to better evaluate automated segmentation tools and apply them not only to research, but eventually to clinical practice.
  • Practical Wisdom and the Program Coordinator
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Richard B. Gunderman
  • Recruiting Medical Students to Interventional Radiology: Current State of
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Juri Bassuner, David Duncan, Chris Molloy, Mina S. Makary, Brycen Bodell, Dylan Assael, Riz Ahmed, Geogy VatakencherryObjectiveInterventional radiology/diagnostic radiology (IR/DR) is the newest primary specialties offered to trainees, one that medical students can now apply to directly out of medical school. However, medical students are disadvantaged in that the integrated IR/DR pathway requires early decision when often radiology rotations are not part of the core clerkship curriculum. Based upon results from a survey to Integrated IR/DR Program Directors, we report strategies being used by programs to introduce and attract medical students to IR.Materials and MethodsA questionnaire was written touching on various aspects of medical student engagement. The questionnaire was sent out electronically to 51 IR/DR Program Directors and answers were collated by the Society of Interventional Radiology Resident Fellow Student Section, IR Residency Training Committee.ResultsEighteen responses were recorded from programs across the country. All programs encouraged applying to both DR and IR programs. All except one offered research opportunities (94%). The majority offered shadowing opportunities, had dedicated IR interest groups, and invited medical students to device workshops (78%). Planned informal opportunities for medical students to meet faculty and a dedicated department website were made available by most (67%). Little more than half invited medical students to journal clubs (59%). Formal medical student-faculty mentorship program and social media outreach initiatives like Facebook, Student Doctor Network, Twitter, LikedIn, Youtube, and podcasts rounded out the bottom two (50%). Importantly, respondents indicated that they were interested in hearing the results of the survey.ConclusionOur survey offers a snapshot of exactly what program directors are doing to address the issue of medical student recruitment.
  • Soft Tissue Sarcomas: Preoperative Predictive Histopathological Grading
           Based on Radiomics of MRI
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Yu Zhang, Yifeng Zhu, Xiaomeng Shi, Juan Tao, Jingjing Cui, Yue Dai, Minting Zheng, Shaowu WangRationale and ObjectivesThe purpose of this study is to develop a radiomics model for predicting the histopathological grades of soft tissue sarcomas preoperatively through magnetic resonance imaging (MRI).Materials and MethodsThirty-five patients who were pathologically diagnosed with soft tissue sarcomas and their histological grades were recruited. All patients had undergone MRI before surgery on a 3.0T MRI scanner. Radiomics features were extracted from fat-suppressed T2-weighted imaging. We used the least absolute shrinkage and selection operator (LASSO) regression method to select features. Then three machine learning classification methods, including random forests, k-nearest neighbor, and support vector machine algorithm were trained using the 5-fold cross validation strategy to separate the soft tissue sarcomas with low- and high-histopathological grades.ResultsThe radiomics features were significantly associated with the histopathological grades. Quantitative imaging features (n = 1049) were extracted from fat-suppressed T2-weighted imaging, and five features were selected to construct the radiomics model. The model that used support vector machine classification method achieved the best performance among the three methods, with areas under the receiver operating characteristic curves Area Under Curve (AUC) values of 0.92 ± 0.07, accuracy of 0.88.ConclusionGood accuracy and AUC could be obtained using only five radiomic features. Therefore, we proposed that three-dimensional imaging features from fat-suppressed T2-weighted imaging could be used as candidate biomarkers for preoperative prediction of histopathological grades of soft tissue sarcomas noninvasively.
  • Radiomics Signature: A Biomarker for the Preoperative Distant Metastatic
           Prediction of Stage I Nonsmall Cell Lung Cancer
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Li Fan, MengJie Fang, WenTing Tu, Di Zhang, Yun Wang, Xiuxiu Zhou, Yi Xia, ZhaoBin Li, ShiYuan LiuObjectivesTo evaluate the predictive value of radiomics features on the distant metastasis (DM) of stage I nonsmall cell lung cancer (NSCLC) preoperatively, by comparing with clinical characteristics and CT morphological features, and to screen the important prognostic predictors.MethodsOne hundred ninety-four stage I NSCLC patients were retrospectively enrolled, DM free survival (DMFS) was evaluated. The consensus clustering analysis was used to build the radiomics signatures in the primary cohort and validated in the validation cohort. The univariate survival analysis was performed in clinical characteristics, CT morphological features and radiomics signatures, respectively. Cox model was performed and C-index was calculated.ResultsThere were 25 patients (12.9%) with DM. The median DMFS was 15 months. Three hundred thirteen radiomics features were selected, then classified into five groups, two subtypes (I and II) with each group. The RS1 showed the best prognostic ability with C-index of 0.355(95% confidence interval [CI], 0.269–0.442; p < 0.001). The histological type exhibited a good prognostic ability with C-index of 0.123 (95% CI, 0.000–0.305; p < 0.001) for DMFS. Cox model showed RS1(hazard ratio [HR] 18.025, 95% CI 2.366–137.340), pleural indentation sign (HR 2.623, 95% CI 1.070–6.426) and histological type (HR 4.461, 95% CI 1.783–11.162) were the independent prognostic factors (p < 0.05).ConclusionRadiomics provided a new modality for the distant metastatic prediction of stage I NSCLC. Patients with type II of RS1, pleural indentation sign and nonadenocarcinoma indicated the high probability of postsurgical DM.
  • Radiomics for Classification of Lung Cancer Histological Subtypes Based on
           Nonenhanced Computed Tomography
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Linning E, Lin Lu, Li Li, Hao Yang, Lawrence H. Schwartz, Binsheng ZhaoObjectivesTo evaluate the performance of using radiomics method to classify lung cancer histological subtypes based on nonenhanced computed tomography images.Materials and Methods278 patients with pathologically confirmed lung cancer were collected, including 181 nonsmall cell lung cancer (NSCLC) and 97 small cell lung cancers (SCLC) patients. Among the NSCLC patients, 88 patients were adenocarcinomas (AD) and 93 patients were squamous cell carcinomas (SCC). In total, 1695 quantitative radiomic features (QRF) were calculated from the primary lung cancer tumor in each patient. To build radiomic classification model based on the extracted QRFs, several machine-learning algorithms were applied sequentially. First, unsupervised hierarchical clustering was used to exclude highly correlated QRFs; second, the minimum Redundancy Maximum Relevance feature selection algorithm was employed to select informative and nonredundant QRFs; finally, the Incremental Forward Search and Support Vector Machine classification algorithms were used to combine the selected QRFs and build the model. In our work, to study the phenotypic differences among lung cancer histological subtypes, four classification models were built. They were models of SCLC vs NSCLC, SCLC vs AD, SCLC vs SCC, and AD vs SCC. The performance of the classification models was evaluated by the area under the receiver operating characteristic curve (AUC) estimated by three-fold cross-validation.ResultsThe AUC (95% confidence interval) for the model of SCLC vs NSCLC was 0.741(0.678, 0.795). For the models of SCLC vs AD and SCLC vs SCC, the AUCs were 0.822(0.755, 0.875) and 0.665(0.583, 0.738), respectively. The AUC for the model of AD vs SCC was 0.655(0.570, 0.731). Several QRFs (“Law_15,” “LoG_Uniformity,” “GLCM_Contrast,” and “Compactness Factor”) that characterize tumor heterogeneity and shape were selected as the significant features to build the models.ConclusionOur results show that phenotypic differences exist among different lung cancer histological subtypes on nonenhanced computed tomography image.
  • Separating High-Z Oral Contrast From Intravascular Iodine Contrast in an
           Animal Model Using Dual-Layer Spectral CT
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Todd C. Soesbe, Matthew A. Lewis, Khaled Nasr, Lakshmi Ananthakrishnan, Robert E. LenkinskiRationale and ObjectivesTo show that water and iodine two-material decomposition images from dual-layer dual-energy spectral X-ray computed tomography (DECT) can be used to separate intravascular iodine contrast from simultaneously administered oral tantalum, tungsten, or rhenium contrast in an animal model.Materials and MethodsIn this Institutional Animal Care and Use Committee approved study, four female Fischer rats were given simultaneous intravenous and oral X-ray computed tomography contrast. Intravenous iodine contrast was administered via tail vein injection. Oral barium, tantalum, tungsten, or rhenium contrast was administered via gavage. The animals were imaged on a dual-layer DECT system at 120 kVp. Water and iodine two-material decomposition images (water equivalent and iodine equivalent images) were used for qualitative analysis. Computer simulations were performed using a customized DECT simulator to better understand why certain high-Z elements disappear in the iodine equivalent images and what is the theoretical range of elements with this property.ResultsThe iodine and barium contrast appeared only in the iodine equivalent images and could not be differentiated from each other. However, the tantalum, tungsten, and rhenium contrast only appeared in the water equivalent images. This allowed iodine contrast in the bowel wall to be easily segmented from tantalum, tungsten, and rhenium contrast in the bowel lumen. Simulations confirmed that certain high-Z elements will have pixel values of ≤0 mg iodine/mL in the iodine equivalent images due to a K-edge effect associated with DECT systems.ConclusionsDual-layer DECT can separate iodine from certain high-Z elements using water equivalent and iodine equivalent images with an increased element range compared to other DECT systems. This K-edge effect could promote the development and approval of new high-Z contrast agents for DECT.
  • Role of Iterative Reconstruction Algorithm for the Assessment of
           Myocardial Infarction with Dual Energy Computed Tomography
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Gaston A. Rodriguez-Granillo, Alejandro Deviggiano, Carlos Capunay, Macarena De Zan, Carlos Fernandez-Pereira, Patricia CarrascosaRationale and ObjectivesLow monochromatic energy levels (40 keV) derived from delayed enhancement dual energy cardiac computed tomography (DE-DECT) allow the evaluation of myocardial infarcts (MI) among stable patients, although at the expense of high image noise. We explored whether the application of adaptive statistical iterative reconstruction (ASIR) to 40-keV DE-DECT (unavailable with previous software versions) might improve image quality and detection of MI in stable patients.Materials and MethodsWe prospectively enrolled patients with a history of previous MI, and performed delayed-enhancement cardiac magnetic resonance (DE-CMR) and DE-DECT within the same week. DE-DECT images were reconstructed with 0% and 60% ASIR.ResultsMI was identified in 18 (80%) patients with both DE-CMR and DE-DECT. On a per segment basis, we did not identify significant differences regarding the diagnostic performance of DE-DECT with and without ASIR [area under receiver operating characteristic curve 0.86 vs. 0.83, p = 0.10]. The application of ASIR improved the signal-to-noise ratio of DE-DECT with 0% ASIR compared to DE-DECT with 60% ASIR (6.07 ± 2.1 vs. 11.1 ± 4.5, p < 0.0001). However, qualitative assessment of MI image quality (3.35 ± 1.2, vs. 3.55 ± 1.1, p = 0.10) and diagnostic confidence (4.40 ± 0.9 vs. 4.60 ± 0.8, p = 0.10) were not significantly improved. Using DE-DECT with 60% ASIR, a threshold over 199 HU showed a sensitivity of 67% and a specificity of 92% for the detection of segments with MI.ConclusionIn this study, DE-DECT allowed accurate detection of MI among stable patients compared with DE-CMR, and the application of ASIR improved signal-to-noise ratio of DE-DECT, although the diagnostic performance showed only non-significant improvements.
  • Utility of 13N-Ammonia PET/CT to Detect Pituitary Tissue in Patients with
           Pituitary Adenomas
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Zongming Wang, Zhigang Mao, Xiangsong Zhang, Dongsheng He, Xin Wang, Qiu Du, Zheng Xiao, Diming Zhu, Yonghong Zhu, Haijun WangRationale and ObjectivesIt is clinically essential, but sometimes challenging, to distinguish pituitary tissue from pituitary adenomas (PAs). It is helpful to avoid damage of pituitary tissue during management. We evaluated the ability of 13N-ammonia positron emission tomography (PET)/computed tomography (CT) to locate and distinguish pituitary tissue from PAs.Materials and MethodsForty-eight patients (four with prolactinoma, 10 with Cushing's disease, 12 with acromegaly, and 22 with nonfunctional PAs) prospectively underwent magnetic resonance imaging (MRI), 13N-ammonia PET/CT, 18F-FDG PET/CT, prior to surgery.ResultsPituitary position could be determined in 31 (64.5%) patients by 13N-ammonia PET/CT, and by MRI in 26 (54.2%) patients. It was detected by 13N-ammonia PET/CT and MRI in eight of eight patients (100%) with pituitary microadenoma, tumor maximum diameter (TMD)
  • Quantitative Assessment of Tumor Cell Proliferation in Brain Gliomas with
           Dynamic Contrast-Enhanced MRI
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Jia Shen Jiang, Ye Hua, Xue Jun Zhou, Dan Dan Shen, Jin Long Shi, Min Ge, Qi Nan Geng, Zhong Zheng JiaRationale and ObjectivesThis study aimed to investigate whether volume transfer constant (Ktrans) and volume of extravascular extracellular space per unit volume of tissue (Ve) derived from dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) could quantitatively assess the tumor proliferation index (Ki-67) of gliomas noninvasively.Materials and MethodsThe preoperative DCE MRI data of 69 patients with pathologically confirmed glioma (28, 8, and 33 cases in grades Ⅱ, Ⅲ, and Ⅳ) were retrospectively reviewed. The maximal Ktrans and Ve were measured in the tumor body. The immunohistochemistry was used to detect the expression of Ki-67 proteins in glioma specimens. The Mann–Whitney U test was applied to analyze the differences in Ktrans, Ve, and Ki-67 index across histologically defined glioma grades. Spearman correlation was performed between Ktrans, Ve, and Ki-67 index. The receiver operating characteristic curve analysis was used to determine the cutoff values of Ktrans and Ve in distinguishing different Ki-67 index expression levels.ResultsKtrans, Ve, and Ki-67 index of grade Ⅱ (0.027 min−1, 0.065, 4.04%) were significantly lower than those of grade Ⅲ (0.093 min−1, 0.297, 25.13%) and Ⅳ (0.100 min−1, 0.299, 25.37%). Both Ktrans and Ve significantly correlated with the Ki-67 index in all tumors and high-grade gliomas (HGGs, grade Ⅲ and Ⅳ). The receiver operating characteristic curve analysis revealed that the cutoff values for Ktrans (0.079 min−1) and Ve (0.249) provided the best combination of sensitivity and specificity to distinguish the gliomas with high Ki-67 index from those with low Ki-67 index.ConclusionThe DCE MRI-derived parameters were valuable in assessing the tumor cell proliferation in HGG noninvasively.
  • Influence of Inspiratory/Expiratory CT Registration on Quantitative Air
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Oliver Weinheimer, Benjamin A. Hoff, Aleksa B. Fortuna, Antonio Fernández-Baldera, Philip Konietzke, Mark O. Wielpütz, Terry E. Robinson, Craig J. GalbánRationale and ObjectivesThe aim of this study was to assess variability in quantitative air trapping (QAT) measurements derived from spatially aligned expiration CT scans.Materials and MethodsSixty-four paired CT examinations, from 16 school-age cystic fibrosis subjects examined at four separate time intervals, were used in this study. For each pair, visually inspected lobe segmentation maps were generated and expiration CT data were registered to the inspiration CT frame. Measurements of QAT, the percentage of voxels on the expiration CT scan below a set threshold were calculated for each lobe and whole-lung from the registered expiration CT and compared to the true values from the unregistered data.ResultsA mathematical model, which simulates the effect of variable regions of lung deformation on QAT values calculated from aligned to those from unaligned data, showed the potential for large bias. Assessment of experimental QAT measurements using Bland-Altman plots corroborated the model simulations, demonstrating biases greater than 5% when QAT was approximately 40% of lung volume. These biases were removed when calculating QAT from aligned expiration CT data using the determinant of the Jacobian matrix. We found, by Dice coefficient analysis, good agreement between aligned expiration and inspiration segmentation maps for the whole-lung and all but one lobe (Dice coefficient> 0.9), with only the lingula generating a value below 0.9 (mean and standard deviation of 0.85 ± 0.06).ConclusionThe subtle and predictable variability in corrected QAT observed in this study suggests that image registration is reliable in preserving the accuracy of the quantitative metrics.
  • Machine Learning Algorithms Utilizing Functional Respiratory Imaging May
           Predict COPD Exacerbations
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Maarten Lanclus, Johan Clukers, Cedric Van Holsbeke, Wim Vos, Glenn Leemans, Birgit Holbrechts, Katherine Barboza, Wilfried De Backer, Jan De BackerRationale and ObjectivesAcute chronic obstructive pulmonary disease exacerbations (AECOPD) have a significant negative impact on the quality of life and accelerate progression of the disease. Functional respiratory imaging (FRI) has the potential to better characterize this disease. The purpose of this study was to identify FRI parameters specific to AECOPD and assess their ability to predict future AECOPD, by use of machine learning algorithms, enabling a better understanding and quantification of disease manifestation and progression.Materials and MethodsA multicenter cohort of 62 patients with COPD was analyzed. FRI obtained from baseline high resolution CT data (unenhanced and volume gated), clinical, and pulmonary function test were analyzed and incorporated into machine learning algorithms.ResultsA total of 11 baseline FRI parameters could significantly distinguish ( p < 0.05) the development of AECOPD from a stable period. In contrast, no baseline clinical or pulmonary function test parameters allowed significant classification. Furthermore, using Support Vector Machines, an accuracy of 80.65% and positive predictive value of 82.35% could be obtained by combining baseline FRI features such as total specific image-based airway volume and total specific image-based airway resistance, measured at functional residual capacity. Patients who developed an AECOPD, showed significantly smaller airway volumes and (hence) significantly higher airway resistances at baseline.ConclusionThis study indicates that FRI is a sensitive tool (PPV 82.35%) for predicting future AECOPD on a patient specific level in contrast to classical clinical parameters.
  • Calibrated Breast Density Measurements
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Erin E. Fowler, Autumn Smallwood, Nadia Khan, Cassandra Miltich, Jennifer Drukteinis, Thomas A. Sellers, John HeineRationale and ObjectivesMammographic density is an important risk factor for breast cancer, but translation to the clinic requires assurance that prior work based on mammography is applicable to current technologies. The purpose of this work is to evaluate whether a calibration methodology developed previously produces breast density metrics predictive of breast cancer risk when applied to a case–control study.Materials and MethodsA matched case control study (n = 319 pairs) was used to evaluate two calibrated measures of breast density. Two-dimensional mammograms were acquired from six Hologic mammography units: three conventional Selenia two-dimensional full-field digital mammography systems and three Dimensions digital breast tomosynthesis systems. We evaluated the capability of two calibrated breast density measures to quantify breast cancer risk: the mean (PGm) and standard deviation (PGsd) of the calibrated pixels. Matching variables included age, hormone replacement therapy usage/duration, screening history, and mammography unit. Calibrated measures were compared to the percentage of breast density (PD) determined with the operator-assisted Cumulus method. Conditional logistic regression was used to generate odds ratios (ORs) from continuous and quartile (Q) models with 95% confidence intervals. The area under the receiver operating characteristic curve (Az) was also used as a comparison metric. Both univariate models and models adjusted for body mass index and ethnicity were evaluated.ResultsIn adjusted models, both PGsd and PD were statistically significantly associated with breast cancer with similar Az of 0.61–0.62. The corresponding ORs and confidence intervals were also similar. For PGsd, the OR was 1.34 (1.09, 1.66) for the continuous measure and 1.83 (1.11, 3.02), 2.19 (1.28, 3.73), and 2.20 (1.26, 3.85) for Q2–Q4. For PD, the OR was 1.43 (1.16, 1.76) for the continuous measure and 0.84 (0.52, 1.38), 1.96 (1.19, 3.23), and 2.27 (1.29, 4.00) for Q2–Q4. The results for PGm were slightly attenuated and not statistically significant. The OR was 1.22 (0.99, 1.51) with Az = 0.60 for the continuous measure and 1.24 (0.78, 1.97), 0.98 (0.60, 1.61), and 1.26, (0.77, 2.07) for Q2–Q4 with Az = 0.60.ConclusionThe calibrated PGsd measure provided significant associations with breast cancer comparable to those given by PD. The calibrated PGm performed slightly worse. These findings indicate that the calibration approach developed previously replicates under more general conditions.
  • Selection of Fitting Model and Arterial Input Function for Repeatability
           in Dynamic Contrast-Enhanced Prostate MRI
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Sharon Peled, Mark Vangel, Ron Kikinis, Clare M. Tempany, Fiona M. Fennessy, Andrey FedorovRationale and ObjectivesAnalysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging is notable for the variability of calculated parameters. The purpose of this study was to evaluate the level of measurement variability and error/variability due to modeling in DCE magnetic resonance imaging parameters.Materials and MethodsTwo prostate DCE scans were performed on 11 treatment-naïve patients with suspected or confirmed prostate peripheral zone cancer within an interval of less than two weeks. Tumor-suspicious and normal-appearing regions of interest (ROI) in the prostate peripheral zone were segmented. Different Tofts-Kety based models and different arterial input functions, with and without bolus arrival time (BAT) correction, were used to extract pharmacokinetic parameters. The percent repeatability coefficient (%RC) of fitted model parameters Ktrans, ve, and kep was calculated. Paired t-tests comparing parameters in tumor-suspicious ROIs and in normal-appearing tissue evaluated each parameter's sensitivity to pathology.ResultsAlthough goodness-of-fit criteria favored the four-parameter extended Tofts-Kety model with the BAT correction included, the simplest two-parameter Tofts-Kety model overall yielded the best repeatability scores. The best %RC in the tumor-suspicious ROI was 63% for kep, 28% for ve, and 83% for Ktrans . The best p values for discrimination between tissues were p
  • Texture Analysis Based on Preoperative Magnetic Resonance Imaging (MRI)
           and Conventional MRI Features for Predicting the Early Recurrence of
           Single Hepatocellular Carcinoma after Hepatectomy
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Jing Zhang, Xinjie Liu, Haiping Zhang, Xiaojing He, Yangyang Liu, Jun Zhou, Dajing GuoRationale and ObjectivesTo investigate the value of texture analysis and conventional magnetic resonance imaging (MRI) features for predicting the early recurrence (ER) of single hepatocellular carcinoma (HCC) after hepatectomy.Materials and MethodsA total of 100 HCC patients were first divided into group A (tumor diameter ≤3 cm) and group B (tumor diameter>3 cm) and then classified into two subgroups with ER or nonearly recurrence. Textural parameters (skewness, kurtosis, uniformity, energy, entropy, and correlation) based on MR images and conventional MRI features were compared between the ER and nonearly recurrence subgroups. Predictive factors for ER were further assessed with multivariate logistic regression analysis. Receiver operating characteristic curve was performed to assess the predictive power.ResultsThere were 53 patients in group A and 47 patients in group B. On arterial phase analysis, tumors with ER displayed significantly lower uniformity and higher entropy in group A, and higher skewness and entropy in group B. On portal venous phase analysis, tumors with ER had significantly lower kurtosis and energy in group A, and higher entropy in group B. Irregular margin in groups A and B, and arterial peritumoral enhancement and capsule presence in group B were associated with ER. In multivariate logistic regression analysis, uniformity and entropy based on arterial phase images and irregular margin in group A, and skewness and entropy based on arterial phase images and arterial peritumoral enhancement in group B were independent predictors for ER. Entropy displayed higher predictive power for ER.ConclusionTexture analysis based on preoperative MRI are potential quantitative predictors of ER in HCC patients after hepatectomy, and may provide more information for preoperative treatment decision-making and follow up.
  • Dose Optimization of Perfusion-derived Response Assessment in
           Hepatocellular Carcinoma Treated with Transarterial Chemoembolization:
           Comparison of Volume Perfusion CT and Iodine Concentration
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Wolfgang M. Thaiss, Ulrike Haberland, Sascha Kaufmann, Tobias Hepp, Maximilian Schulze, Anya C. Blum, Dominik Ketelsen, Konstantin Nikolaou, Marius Horger, Alexander W. SauterRationale and ObjectivesWe assessed the value of iodine concentration (IC) as a perfusion-derived response marker for hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE) in comparison with volume perfusion computed tomography (VPCT) parameters.Materials and MethodsForty-one HCC lesions in 32 patients examined before and after TACE were analyzed retrospectively. VPCT-parameters were calculated and lesion iodine-maps were computed using subtraction of the baseline and the scan 7 seconds after aortic peak enhancement from the corresponding 80 kVp-VPCT data set. Modified RECIST was used as standard response criteria. Comparisons were performed using Student's t test for normal distributed data and Mann–Whitney U test for non-normal distributed data. Additionally, correlation analysis, receiver operating characteristics (ROC) and interreader agreement were assessed.ResultsIn responding lesions, mean pre-TACE IC and blood flow (BF) were 131.2 mg/100 mL and 96.7 mL/100 mL/min, decreasing to IC 25.6 mg/100 mL (P < 0.001) and BF 28.5 mL/100 mL/min (P < 0.001) post-TACE. In nonresponding lesions, the values remained almost unchanged: pre-TACE: mean BF 79.3 mL/100 mL/min and mean IC 90.4 mg/100 mL; post-TACE: mean BF 71.3 mL/100 mL/min (n.s.) and mean IC 105.4 mg/100 mL (n.s.). Differences in IC-values revealed a high sensitivity/specificity of 96.7%/81.8%. IC and VPCT-parameters showed strong, positive correlations. Mean volume CT dose index for VPCT was 63.4 mGy and 4.9 mGy for iodine maps.ConclusionThus, IC is a meaningful perfusion marker for local therapy response monitoring in HCC that can be acquired with low radiation dose. This information is important for further therapy response applications using dual and single energy CT.
  • Quantitative Assessment of Bladder Cancer Reflects Grade and Recurrence:
           Comparing of Three Methods of Positioning Region of Interest for ADC
           Measurements at Diffusion-weighted MR Imaging
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Hongyi Li, Lin Liu, Lei Ding, Zhenming Zhang, Mengchao ZhangPurposeTo determine the impact of three different regions of interests (ROIs) positioning methods for apparent diffusion coefficient (ADC) measurements on the assessment of the grade and recurrence and to examine the correlation between ADC value and histopathological grade/ Ki-67 labeling index (LI) in patients with bladder cancer.Materials and MethodsSixty-one patients with bladder cancer were retrospectively evaluated. Two observers measured mean ADC values using whole-volume-ROIs, single-section-ROI and three-ROIs methods. Interclass correlation coefficient was analyzed to assess interobserver variability. The grade and recurrence in patients with bladder cancer were assessed by calculating the areas under the receiver operating characteristic curves with Az values. Spearman's correlation was used to analyze the correlations of ADC value with grade and Ki-67 LI.ResultsFor the mean ADC value, the interclass correlation coefficient were excellent with the whole-volume and the single-section method (0.90 [95% CI: 0.84, 0.94] and 0.89 [95% CI: 0.81, 0.93]) and was good with the three-ROIs method (0.72 [95% CI: 0.53, 0.83]). The Az value for determining histological grade and recurrence of bladder cancer were not significantly different from each positioning method (all p> 0.05). There's significant correlation between histological grade and ADC measuring by whole-volume-ROIs and single-section-ROI methods (r = 0.31, p = 0.02; r = 0.37, p < 0.05). The ADC measured by whole-volume-ROIs, single-section-ROI, and three-ROIs methods were significantly and inversely correlated with the Ki-67 LI (r = −0.3; r = −0.49; r = −0.40, all p < 0.05).ConclusionThere's no significant difference among any of the ROI positioning methods in evaluation of tumor grade and recurrence. There's significant correlation between histological grade and ADC measuring by whole-volume-ROIs and single-section-ROI methods. The ADC value obtained by either of three methods was significantly and inversely correlated with the Ki-67 LI.
  • Diagnostic Accuracy of CT for Prediction of Bladder Cancer Treatment
           Response with and without Computerized Decision Support
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Kenny H. Cha, Lubomir M. Hadjiiski, PhD, Richard H. Cohan, MD, Heang-Ping Chan, PhD, Elaine M. Caoili, MD, Matthew Davenport, MD, Ravi K. Samala, PhD, Alon Z. Weizer, MD, Ajjai Alva, MD, Galina Kirova-Nedyalkova, MD, PhD, Kimberly Shampain, MD, Nathaniel Meyer, MD, Daniel Barkmeier, MD, PhD, Sean Woolen, MD, Prasad R. Shankar, MD, Isaac R. Francis, MD, Phillip Palmbos, MDRationale and ObjectivesTo evaluate whether a computed tomography (CT)-based computerized decision-support system for muscle-invasive bladder cancer treatment response assessment (CDSS-T) can improve identification of patients who have responded completely to neoadjuvant chemotherapy.Materials and MethodsFollowing Institutional Review Board approval, pre-chemotherapy and post-chemotherapy CT scans of 123 subjects with 157 muscle-invasive bladder cancer foci were collected retrospectively. CT data were analyzed with a CDSS-T that uses a combination of deep-learning convolutional neural network and radiomic features to distinguish muscle-invasive bladder cancers that have fully responded to neoadjuvant treatment from those that have not. Leave-one-case-out cross-validation was used to minimize overfitting. Five attending abdominal radiologists, four diagnostic radiology residents, two attending oncologists, and one attending urologist estimated the likelihood of pathologic T0 disease (complete response) by viewing paired pre/post-treatment CT scans placed side-by-side on an internally-developed graphical user interface. The observers provided an estimate without use of CDSS-T and then were permitted to revise their estimate after a CDSS-T-derived likelihood score was displayed. Observer estimates were analyzed with multi-reader, multi-case receiver operating characteristic methodology. The area under the curve (AUC) and the statistical significance of the difference were estimated.ResultsThe mean AUCs for assessment of pathologic T0 disease were 0.80 for CDSS-T alone, 0.74 for physicians not using CDSS-T, and 0.77 for physicians using CDSS-T. The increase in the physicians' performance was statistically significant (P < .05).ConclusionCDSS-T improves physician performance for identifying complete response of muscle-invasive bladder cancer to neoadjuvant chemotherapy.
  • Hybrid Interactive and Didactic Teaching Format Improves Resident
           Retention and Attention Compared to Traditional Lectures
    • Abstract: Publication date: September 2019Source: Academic Radiology, Volume 26, Issue 9Author(s): Vishwan Pamarthi, Lars Grimm, Karen Johnson, Charles MaxfieldPurposeTo compare the traditional lecture to a hybrid interactive and didactic teaching format with regards to radiology resident short- and long-term retention, as well as attention.Materials and MethodsThe tested hybrid format consists of a 30-minute didactic lecture followed by 30 minutes of interactive cases based on material from the lecture portion. Faculty members were randomly selected to give a 60-minute lecture or a hybrid presentation. To assess short- and long-term retention, a test developed from the presenter's slides was sent to all residents approximately 15 minutes after each presentation, and again approximately 3 months later. The presenters were blinded to the survey questions. Attention was assessed by comparing the proportion of questions answered correctly from each quarter of the presentation. Equality in difficulty of questions was validated across teaching methods.ResultsFor 6 hybrid presentations, 106 and 60 retention tests were submitted, answering 848 and 480 short- and long-term survey questions, respectively. For 6 lectures, 91 and 55 retention tests were submitted, answering 728 and 440 short- and long-term survey questions, respectively. Short-term retention was 75.7% (640/848) for hybrid presentations, versus 63.2% (460/728) for lectures (p < 0.0001). Long-term retention was 59.4% (285/480) for hybrid presentations, versus 49.3% (217/440) for lectures (p = 0.002). Regarding attention, 61.6% (554/600) of questions from the first 3 quarters of traditional lectures were answered correctly versus 49.3% (148/300) of final quarter questions (p = 0.0003). No significant drop-off was noted for hybrid presentations.ConclusionA hybrid interactive and didactic teaching format for radiology residents demonstrates better short-term retention, long-term retention, and attention when compared to traditional lectures.
  • The USMLE Step 1 Pass/Fail Reporting Proposal: The APDR Position
    • Abstract: Publication date: Available online 2 August 2019Source: Academic RadiologyAuthor(s): Anna Rozenshtein, Mark E. Mullins, M. Victoria MarxBackgroundThe National Board of Medical Examiners (NBME) and the United States Medical Licensing Examination (USMLE) has convened a conference of “key stakeholders” on March 11–12, 2019 to consider reporting the results of the USMLE Step 1 as pass/fail.DiscussionWhile the original purpose of the USMLE Step 1 was to provide an objective basis for medical licensing, the score is increasingly used in residency applicant screening and selection because it is an objective, nationally recognized metric allowing comparison across medical schools in and outside the United States. Excessive reliance on the Step 1 score in the matching process has led to “Step 1 Culture” that drives medical schools to “teach to the test,” increases medical student anxiety, and disadvantages minorities that have been shown to score lower on the USMLE Step 1 examination.The outsize role of the USMLE Step 1 score in resident selection is due to lack of standardization in medical school transcripts, grade inflation, and the lack of class standing in many summative assessments. Furthermore, the numeric score allows initial Electronic Residency Application Service filtering, commonly used by programs to limit the number of residency applications to review.ConclusionThe Association of Program Directors in Radiology (APDR) is concerned that pass/fail reporting of the USMLE Step 1 score would take away an objective measure of medical student's knowledge and the incentive to acquire as much of it as possible. Although the APDR is not in favor of the Step 1 exam being used as a screening tool, in the absence of an equal or better metric for applicant comparison the APDR opposes the change in Step 1 reporting from the numeric score to pass/fail.
  • Gender Differences Among Academic Pediatric Radiology Faculty in the
           United States and Canada
    • Abstract: Publication date: Available online 29 July 2019Source: Academic RadiologyAuthor(s): William B. Counter, Kiran Khurshid, Sabeena Jalal, Mauricio Castillo, Ammie M. White, Hansel J. Otero, Savvas Nicolaou, Faisal KhosaObjectiveIt is currently unknown whether efforts in recent years to create equal opportunities for female faculty in academic medicine have succeeded. We looked at faculty members in academic pediatric radiology departments across the United States and Canada to assess for evidence of gender disparities and differences in academic performance between males and females.MethodsThe analysis included diagnostic radiology programs across the United States and Canada, as specified by the American Medical Association's Fellowship and Residency Electronic Interactive Database (FREIDA Online) and the Canadian Resident Matching Service website. The Scopus database was used to retrieve the H-index, number of publications, and number of citations for each faculty member. We examined the distribution of male and female faculty members across geographical regions, academic ranks, and leadership roles. Academic performance was also compared.ResultsAcross all regions and academic ranks, disparities exist between the number of male and female faculty members. The greatest disparity was found amongst the professor rank, where more than 70% of positions were occupied by males. Female professors were found to demonstrate similar levels of academic performance compared to their male counterparts, although this parity was not observed amongst assistant and associate professors.ConclusionWomen occupied almost half (46.6%) of the total academic pediatric radiology workforce, despite having been previously shown to make up only 21% of radiologists. However, gender disparities currently exist among academic pediatric radiology faculty, with a significantly higher percentage of men in pediatric radiology faculty positions. Women, however, currently occupy a greater percentage of leadership positions compared to men, even though the majority of senior academic ranks are held by men.
  • Variation in Technical Quality of Breast MRI
    • Abstract: Publication date: Available online 29 July 2019Source: Academic RadiologyAuthor(s): Lorell Ruiz-Flores, Gary J. Whitman, H.T Carissa Le-Petross, Kenneth R. Hess, Jay R. ParikhPurposeBreast magnetic resonance imaging (MRI) quality may vary across the United States. Our aim was to investigate the quality of outside breast MRIs presenting for second opinion at a tertiary cancer center following implementation of the American College of Radiology (ACR) Breast MRI Accreditation Program.Materials and MethodsWe retrospectively reviewed the technical quality of the MRI studies of 100 consecutive cases submitted for second opinion in 2013. The image quality was blindly reviewed per ACR Breast MRI Accreditation Program by three fellowship-trained breast radiologists and one breast imaging fellow.ResultsIn total, 88 of the 100 cases were referred from facilities in the United States. Sixty (68%) of the 88 cases had at least one technical deficiency. In 10 cases (11%), more than five different technical deficiencies occurred. The most frequently encountered deficiencies were related to artifacts (74%), with shimming (N = 17) and motion (N = 16) being the most common. In total, 38% of cases (N = 33) had a deficient T2-weighted sequence, mostly due to low signal to noise ratio (N = 25). A total of 27% cases (N = 24) had deficiencies in the delayed phase postcontrast T1-weighted sequence, mainly due to low signal to noise ratio (N = 21) and 23% had deficiencies in the early phase postcontrast T1-weighted sequence, predominantly due to low signal to noise ratio as well. (N = 19).ConclusionOur study demonstrates variability of breast MRI quality across the United States. Radiologists should become familiar with the requirements of the ACR breast MRI accreditation program and strive to meet the expected standards in order to enhance patient quality and safety.
  • Vertical Off-Centering in Reduced Dose Chest-CT: Impact on Effective Dose
           and Image Noise Values
    • Abstract: Publication date: Available online 27 July 2019Source: Academic RadiologyAuthor(s): Matthias Eberhard, Christian Blüthgen, Borna K. Barth, Thomas Frauenfelder, Natalia Saltybaeva, Katharina MartiniObjectivesTo assess the effect of vertical off-centering in tube current modulation (TCM) on effective-dose and image-noise in reduced-dose (RD) chest-CT.MethodsOne-hundred consecutive patients (36 female; mean age 56 years) were scanned on a 192-slice CT scanner with a standard-dose (ND) and a RD chest-CT protocol using tube current modulation. Image-noise was evaluated by placing circular regions of interest in the apical, middle, and lower lung regions. Two independent readers evaluated image quality. Study population was stratified according to patient position in the gantry: positioned in the gantry isocenter (i), higher than the gantry isocenter (ii), and lower than the gantry isocenter, (iii). Pearson correlation was used to determine the correlation between effective radiation dose and vertical off-centering. Student's t test was used to evaluate for differences in image-noise between groups (i-iii).ResultsMean vertical off-centering was of 10.6 mm below the gantry-isocenter (range −45.0–27.9 mm). Effective radiation dose varied in a linear trend, with the highest doses noted below gantry isocenter, and the lowest doses noted above gantry isocenter (ND: r = −0.296; p = 0.003 – RD: r = −0.258; p = 0.010). Lowest image-noise was observed where patients were positioned below the gantry isocenter, and highest in patients positioned above (ND: 79.35 HU vs. 94.86 HU – RD: 143.44 HU vs. 160.13 HU). Subjective image quality was not significantly affected by patient-position (p> 0.05). Overall, there was no over-proportional noise-increase from the ND to the RD protocol in patients which were positioned off-center.ConclusionVertical off-centering influences effective radiation dose and image-noise on ND and RD protocols.Advances in KnowledgeThere is no over-proportional noise increase in RD compared to ND protocols when patients are positioned off-center.
  • Solid Science of AI Supporting Bladder Cancer CT Reading
    • Abstract: Publication date: Available online 17 July 2019Source: Academic RadiologyAuthor(s): Henkjan Huisman
  • How Certain Are Your Radiology Reports And Are We Alone in Our
    • Abstract: Publication date: Available online 20 June 2019Source: Academic RadiologyAuthor(s): Elizabeth A. Krupinski
  • Machine Learning Algorithms Utilizing Functional Respiratory Imaging May
           Predict COPD Exacerbations
    • Abstract: Publication date: Available online 19 June 2019Source: Academic RadiologyAuthor(s): Brett W. Carter
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