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Publisher: Elsevier   (Total: 3161 journals)

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Showing 1 - 200 of 3161 Journals sorted alphabetically
A Practical Logic of Cognitive Systems     Full-text available via subscription   (Followers: 9)
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 35, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 24, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 96, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 27, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 37, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 5)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 7)
Acta Astronautica     Hybrid Journal   (Followers: 422, 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: 2)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 10, SJR: 0.18, CiteScore: 1)
Acta Haematologica Polonica     Free   (Followers: 1, SJR: 0.128, CiteScore: 0)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 278, 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: 3, 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: 26, 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: 6, 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: 14, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 17, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 8, 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: 168, 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: 8, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 28, 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: 10, 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: 14, 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: 4)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 13)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 28, 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: 12)
Advances in Digestive Medicine     Open Access   (Followers: 9)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Drug Research     Full-text available via subscription   (Followers: 25)
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: 46, 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: 60, 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: 19, 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: 6, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 24, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 12, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 23)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, 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: 8, 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: 18, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 11, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 7, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 23)
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: 4)
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: 17, 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: 25, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 12)
Advances in Pharmacology     Full-text available via subscription   (Followers: 16, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 8, 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: 5)
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: 65)
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: 404, 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: 12, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 34, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 18)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 14)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 47, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 358, 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: 11, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 465, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 17, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 42, 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: 57, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 6, 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: 1, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 10, 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: 52, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 4, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 4, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 6)
American Heart J.     Hybrid Journal   (Followers: 56, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 59, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 44, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 11)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 13, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 34, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 28, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 35, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 48)
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: 226, 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: 28, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 29, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 38, 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: 63, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 19, 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: 43, SJR: 1.512, CiteScore: 5)
Analytical Biochemistry     Hybrid Journal   (Followers: 190, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 12, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 13)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 23, 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: 205, SJR: 1.58, CiteScore: 3)

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Journal Cover
Academic Radiology
Journal Prestige (SJR): 1.015
Citation Impact (citeScore): 2
Number of Followers: 24  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1076-6332
Published by Elsevier Homepage  [3161 journals]
  • Dynamic Contrast-Enhanced MRI for Measuring Pancreatic Perfusion in Acute
           Pancreatitis: A Preliminary Study
    • Abstract: Publication date: Available online 15 March 2019Source: Academic RadiologyAuthor(s): Ran Hu, Hua Yang, Yong Chen, Ting Zhou, Ju Zhang, Tian Wu Chen, Xiao Ming ZhangRationale and ObjectivesTo assess the characteristics of pancreatic perfusion in normal pancreas and acute pancreatitis (AP) by using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).Method and MaterialsEighty-One AP patients and 26 normal subjects underwent DCE-MRI. The Omitk-Tool was used to analyze perfusion parameters such as Ktrans, Vp, and AUC. The parameters of pancreas between AP and control groups were compared. In AP patients, the parameters were compared between edematous and necrotizing pancreatitis and among different grades of AP as determined by MR severity index (MRSI) and the 2012 Revised Atlanta Classification of AP.ResultsThe Ktrans, Vp, and AUC values of AP were lower than those of the control group (p = 0.007, 0.000, and 0.025). According to MRSI, the Ktrans and AUC values were significantly different between mild and moderate (p = 0.000, 0.000) and between mild and severe (p = 0.008, 0.016) AP but not between moderate and severe AP (p = 0.218, 0.217). Based on the 2012 Revised Atlanta Classification, the Ktrans values were significantly different between mild and moderately severe (p = 0.000) and between mild and severe (p = 0.005) AP, but not between moderately severe and severe AP (p = 0.619). The Ktrans values were significantly different between edematous and necrotizing pancreatitis (p = 0.03).ConclusionThe application of DCE-MRI to evaluate pancreatic perfusion contributes to the diagnosis of AP and its severity grade. Pancreatic perfusion is lower in AP patients than in patients with a normal pancreas, and pancreatic perfusion tends to decrease as the severity of AP increases.
       
  • Image-Guided Percutaneous Gastrostomy Tube Placement is Safe in Patients
           Requiring Aspirin 325 mg
    • Abstract: Publication date: Available online 14 March 2019Source: Academic RadiologyAuthor(s): Ryan S. Dolan, Daryl Goldman, Mark El-Deiry, Nima Kokabi, Zachary L. Bercu, Janice Newsome, Jonathan G. MartinRationale and ObjectivesRequests for gastrostomy tube placement in patients on aspirin (ASA) 325 mg are common, particularly in patients following reconstructive surgery for head and neck cancer, but periprocedural guidelines and recommendations regarding management of high dose aspirin are inconsistent. The purpose of this study was to assess the bleeding risk of percutaneous gastrostomy tube placement in patients on ASA 325 mg.Materials and MethodsThis retrospective study of 213 patients who underwent image-guided “push” percutaneous gastrostomy tube placement compared rates of significant bleeding and other secondary outcomes (including all-cause mortality within 30 days, procedure-related mortality, bowel perforation, abdominal abscess, peritonitis, aspiration pneumonia, intraprocedural airway complications, and tube dislodgement) between patients maintained on ASA 325 mg and patients not on antiplatelet or anticoagulation therapy.ResultsNo significant bleeding episodes occurred in patients on ASA 325 mg, compared to three episodes in patients not on ASA 325 mg (p = 0.37). A patient in each group had aspiration pneumonia possibly related to tube placement. There were no other notable secondary outcomes, including intraprocedural airway complications in this population with complex head and neck anatomy.ConclusionThese findings suggest that holding ASA 325 mg in patients undergoing percutaneous gastrostomy tube placement is not necessary, especially in patients in whom holding ASA would pose considerable risk. Further multi-institutional longitudinal study is warranted to validate these results.
       
  • Advanced Virtual Monoenergetic Imaging: Improvement of Visualization and
           Differentiation of Intramuscular Lesions in Portal-Venous-phase
           Contrast-enhanced Dual-energy CT
    • Abstract: Publication date: Available online 14 March 2019Source: Academic RadiologyAuthor(s): Mareen S. Kraus, Nadja Selo, Lena S. Kiefer, Michael Esser, Omar M. Albtoush, Jakob Weiss, Julian L. Wichmann, Fabian Bamberg, Ahmed E. OthmanPurposeTo evaluate the effect of advanced monoenergetic imaging (MEI+) postprocessing algorithm on the visualization of various intramuscular lesions on portal-venous-phase contrast-enhanced dual-energy computed tomography (DECT).Material and MethodsThirty-nine patients (64.3 ± 11.1 years; 26 males) with various intramuscular lesions ranging from malignancy, bleeding, inflammation, edematous changes, and benign neoplasms were included and underwent DECT (100/Sn150kV). Postprocessing with MEI+ technique was used to reconstruct images at four different keV levels (40, 60, 80, 100) and compared to the standard portal-venous-phase CT (CTpv) images. Image quality was assessed qualitatively (conspicuity, delineation, sharpness, noise, and confidence) by two independent readers using 5-point Likert scales, 5 = excellent; as well as quantitatively by calculating signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR), and area under the receiver operating characteristic (ROC) curve (AUC) for lesion characterization.ResultsHighest lesion enhancement and diagnostic confidence were observed in MEI+ 40keV, with significant differences to CTpv (p < 0.001), as well as for malignant lesions (highest conspicuity, noise, and sharpness in MEI+ 40 keV; p < 0.001). CNR calculations revealed highest values for MEI+ 40keV followed by 60keV with significant differences to CTpv, and increasing energy levels. ROC analysis showed highest diagnostic accuracy for 40-keV MEI+ datasets regarding the detection of malignant/benign lesions with AUC values of 98.9% (95%-confidence interval: 96.5, 100) and a standard error of 1.2, further AUC values decreased to 83.6% for MEI+100.ConclusionMEI+ at low keV levels can significantly improve lesion detection of benign versus malignant intramuscular entities in patients undergoing portal-venous-phase DECT scans due to increased CNR.
       
  • Magnetic Resonance Elastography in Primary Sclerosing Cholangitis:
           Interobserver Agreement for Liver Stiffness Measurement with Manual and
           Automated Methods
    • Abstract: Publication date: Available online 14 March 2019Source: Academic RadiologyAuthor(s): Safa Hoodeshenas, Christopher L. Welle, Patrick J. Navin, Bogdan Dzyubak, John E. Eaton, Richard L. Ehman, Sudhakar K. VenkateshRationale and ObjectivePrimary sclerosing cholangitis, a chronic liver disease causes heterogeneous parenchymal changes and fibrosis. Liver stiffness measurement (LSM) with magnetic resonance Elastography (MRE) may be affected by this heterogeneous distribution. We evaluated interobserver agreement of LSM in primary sclerosing cholangitis (PSC) with manual and automated methods to study the influence of heterogeneous changes.Materials and MethodsA total of 79 consecutive patients with PSC who had a liver MRI and MRE formed the study group. Three readers with 1–3 years’ experience in MRE and a MRE expert (11 years’ experience) independently performed LSM. Each reader manually drew free hand (fROI) and average (aROI) on stiffness maps. Automatic liver elasticity calculation (ALEC) was used to generate automated LSM. The expert fROI was the reference standard. Correlation analysis and absolute intra-class correlation coefficient (ICC) analysis was performed.ResultsLSM data of 79 livers and 315 sections were evaluated. There was excellent ICC between expert and reader fROIs (0.989, 95% confidence interval, and 0.985–0.993) and aROIs (0.971, 95% confidence interval, and 0.953–0.983) and ALEC (0.972, 0.957–0.982) with fROI performing better. The areas measured with fROIs and ALEC had moderate ICC with Expert fROI (0.64 and 0.56, respectively) whereas aROI area had a poor ICC of 0.12. Comparison of multiple methods showed significant differences in LSM between expert fROI and aROI of two readers and no significant differences for fROIs of all three readers.ConclusionLSM with MRE in PSC patients shows excellent interobserver agreement with both fROI and aROI methods with better performance with fROI. fROI may therefore be preferred for LSM measurements in PSC.
       
  • Dual-Energy CT of Material Decomposition Analysis for Detection with Bone
           Marrow Edema in Patients with Vertebral Compression Fractures
    • Abstract: Publication date: Available online 13 March 2019Source: Academic RadiologyAuthor(s): Kyouhei Akisato, Reisuke Nishihara, Hajime Okazaki, Takanori Masuda, Ayako Hironobe, Hiromi Ishizaki, Kondo Shota, Hiroshi Yamaguchi, Yoshinori FunamaRationale and ObjectivesThis study investigated detecting bone marrow edema (BME) in patients with vertebral compression fractures. We compared dual-energy material density analysis images to magnetic resonance imaging (MRI), which is considered the gold standard.Materials and MethodsIn this retrospective study, 260 vertebral bodies from 30 patients (11 males, 19 females, mean age of 81) were assessed by MRI and dual-energy material density analysis. Diagnostic accuracy was assessed using the receiver operating characteristic (ROC) curve. Fifty-two of the 260 vertebral bodies were considered to have BME based on the dual-energy material density analysis images; 50 were deemed to have BME by MRI.ResultsROC analysis of the dual-energy material density analysis values revealed an area under the ROC curve of 0.95 for radiologist 1, 0.97 for radiologist 2, and 0.96 for radiologist 3. A mean cutoff value of 1032.6 mg/cm3 provided an overall sensitivity of 93.0% (95% confidence intervals [CI]: 86.0%–99.9%), specificity of 98.0% (95% CI: 95.5%–99.0%), accuracy of 97.0% (95% CI: 95.2%–99.0%), positive predictive value of 95.0% (95% CI: 81.0%–97.5%), and negative predictive value of 98.0% (95% CI: 93.0%–99.9%).ConclusionBME in patients with vertebral compression fractures can be detected using dual-energy material density analysis images.
       
  • Moving Radiology Workflow to the Electronic Health Record: Quantitative
           and Qualitative Experience From a Large Academic Medical Center
    • Abstract: Publication date: Available online 12 March 2019Source: Academic RadiologyAuthor(s): Benjamin Wildman-Tobriner, Matthew P. Thorpe, Nicholas Said, Wendy L. Ehieli, Christopher J. Roth, Tracy A. JaffeRationale and ObjectivesTo objectively and subjectively evaluate a large, academic radiology department's transition to electronic health record (EHR) centered workflow.Materials and MethodsMultiple metrics were compared from before and after the move to EHR-driven workflow. Examination ordering and reading priority data were obtained for 30days both before and after the transition. Sixteen radiologists were observed opening a computed tomography (CT) examination, and time to open, mouse clicks, and keystrokes were recorded. Information available to the radiologist during interpretation was also compared. Additionally, a 12 question survey was sent out to the residents and faculty both before and after the transition.ResultsImplementation of an eight-level reading priority system increased worklist granularity and improved identification of more urgent studies to read. Radiologists opened CT studies in picture archiving and communications system-driven workflow in 52.4 ± 16.9 seconds using 9.5 ± 3.9 clicks and 6.3 ± 2.9 keystrokes, compared to 17.3 ± 9.5 seconds, 4.8 ± 1.5 clicks, and 0.1 ± 0.3 keystrokes in EHR-driven workflow (p < 0.001 for each measure). More information was available to the radiologist during examination interpretation, and 54.7% of radiologists rated the ease of use of the new system as good or very good (compared to 4.2% for the old system, p < 0.001).ConclusionTransitioning to an EHR-driven workflow at a large academic medical center improved efficiency, was favorable to radiologists, and enhanced examination prioritization.
       
  • The Power of Design Thinking in Medical Education
    • Abstract: Publication date: Available online 11 March 2019Source: Academic RadiologyAuthor(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.
       
  • Dynamic Computed Tomography Perfusion Imaging: Complementary Diagnostic
           Tool in Hepatocellular Carcinoma Assessment From Diagnosis to Treatment
           Follow-up
    • Abstract: Publication date: Available online 7 March 2019Source: Academic RadiologyAuthor(s): Davide Ippolito, Anna Pecorelli, Giulia Querques, Silvia Girolama Drago, Cesare Maino, Cammillo Talei Franzesi, Adam Hatzidakis, Sandro SironiEarly diagnosis of HCC is of paramount importance in order to enable the application of curative treatments. Among these, radiofrequency ablation (RFA) is actually considered the most effective ablative therapy for early stage hepatocellular carcinoma (HCC) not suitable for surgery. On the other hand, transarterial chemoembolization (TACE) represents the standard of care for intermediate stage HCC and compensated liver function. Finally, sorafenib, an oral antiangiogenic targeted drug, is the only approved systemic therapy for advanced HCC with vascular invasion, extrahepatic spread, and well-preserved liver function. Beside traditional radiological techniques, new functional imaging tools have been introduced in order to provide not only morphological information but also quantitative functional data. In this review, we analyze perfusion-CT (pCT) from a technical point of view, describing the main different mathematical analytical models for the quantification of tissue perfusion from acquired CT raw data, the most commonly acquired perfusion parameters, and the technical parameters required to perform a standard pCT examination. Moreover, a systematic review of the literature was performed to assess the role of pCT as an emerging imaging biomarker for HCC diagnosis, response evaluation to RFA, TACE, and sorafenib, and we examine its challenges in HCC management.
       
  • Improving the Degree and Uniformity of Enhancement in Coronary CT
           Angiography with a New Bolus Tracking Method Enabled By Free Breathing
    • Abstract: Publication date: Available online 4 March 2019Source: Academic RadiologyAuthor(s): Le Cao, Xiang Liu, Jianying Li, Wenbin Liang, Tingting Qu, Yanan Li, Xiaoqian Jia, Jianxin GuoRationale and ObjectivesTo demonstrate the improved enhancement degree and uniformity in coronary CT angiography (CCTA) on a 16 cm wide-coverage CT with a new bolus tracking method enabled by free-breathing, in comparison with the conventional breath-holding method.Materials and MethodsA total of 200 patients with suspected coronary heart disease were randomly divided into two groups for CCTA: Group A (n = 100, free-breathing) started CCTA with 2.2 seconds delay after the attenuation in aorta reached 250 HU; Group B (n = 100, breath-holding), used the standard protocol of 80 HU threshold and 8.4 seconds delay. Both groups used the contrast dose rate of 25 mgI/kg/s. CT value and standard deviation in aortic sinus (AS), right coronary artery, left anterior descending, left circumflex, and pericardial fat were measured. Contrast-to-noise ratio for vessels was calculated. Two experienced Radiologists independently reviewed image quality using a 5-point scale (1: nondiagnostic—5: excellent).ResultsThere was no difference in contrast dose, radiation dose, heart rate, and qualitative image quality between the two groups (all p> 0.05). However, Group A had higher mean enhancement in vessels (404 ± 66 HU) than Group B (321 ± 69 HU), and lower coefficients of variation of CT value in aortic sinus, right coronary artery, left anterior descending, and left circumflex (16.3%, 17.7%, 19.2%, and 20.5% vs 21.5%, 22.3%, 23.6%, and 22.9%, respectively), (all p < 0.05).ConclusionA new bolus tracking method enabled by free-breathing in CCTA on a 16 cm wide-coverage CT system increases the enhancement degree and uniformity in coronary arteries, compared with the conventional breath-holding method.
       
  • Structural and Functional Pulmonary Magnetic Resonance Imaging in
           Pediatrics—From the Neonate to the Young Adult
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Laura L. Walkup, Nara S. Higano, Jason C. WoodsThe clinical imaging modalities available to investigate pediatric pulmonary conditions such as bronchopulmonary dysplasia, cystic fibrosis, and asthma are limited primarily to chest x-ray radiograph and computed tomography. As the challenges that historically limited the application of magnetic resonance imaging (MRI) to the lung have been overcome, its clinical potential has greatly expanded. In this review article, recent advances in pulmonary MRI including ultrashort echo time and hyperpolarized-gas MRI techniques are discussed with an emphasis on pediatric research and translational applications.
       
  • Repeatability of Regional Lung Ventilation Quantification Using
           Fluorinated (19F) Gas Magnetic Resonance Imaging
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Marcel Gutberlet, Till F. Kaireit, Andreas Voskrebenzev, Agilo L. Kern, Arnd Obert, Frank Wacker, Jens M. Hohlfeld, Jens Vogel-ClaussenRationale and ObjectivesTo assess the repeatability of global and regional lung ventilation quantification in both healthy subjects and patients with chronic obstructive pulmonary disease (COPD) using fluorinated (19F) gas washout magnetic resonance (MR) imaging in free breathing.Material and MethodsIn this prospective institutional review board-approved study, 12 healthy nonsmokers and eight COPD patients were examined with 19F dynamic gas washout MR imaging in free breathing and with lung function testing. Measurements were repeated within 2 weeks. Lung ventilation was quantified using 19F gas washout time. Repeatability was analyzed for the total lung and on a regional basis using the coefficient of variation (COV) and Bland–Altman plots.ResultsIn healthy subjects and COPD patients, a good repeatability was found for lung ventilation quantification using dynamic 19F gas washout MR imaging on a global (COV < 8%) and regional (COV < 15%) level. Gas washout time was significantly increased in the COPD group compared to the healthy subjects.Conclusion19F gas washout MR imaging provides a good repeatability of lung ventilation quantification and appears to be sensitive to early changes of regional lung function alterations such as normal aging.
       
  • A Model for Predicting Future FEV1 Decline in Smokers Using Hyperpolarized
           3He Magnetic Resonance Imaging
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Ryan J. Baron, Hooman Hamedani, Stephen J. Kadlecek, Ian F. Duncan, Yi Xin, Sarmad Siddiqui, Mehrdad Pourfathi, Maurizio Cereda, Rahim R. RiziRationale and ObjectivesThe purpose of this study was to assess the effectiveness of hyperpolarized helium-3 magnetic resonance (MR)-based imaging markers in predicting future forced expiratory volume in one second decline/chronic obstructive pulmonary disorder progression in smokers compared to current diagnostic techniques.Materials and MethodsTotal 60 subjects (15 nonsmokers and 45 smokers) participated in both baseline and follow-up visits (∼1.4 years apart). At both visits, subjects completed pulmonary function testing, a six-minute walk test , and the St. George Respiratory Questionnaire. Using helium-3 MR imaging, means (M) and standard deviations (H) of oxygen tension (PAO2), fractional ventilation, and apparent diffusion coefficient were calculated across 12 regions of interest in the lungs. Subjects who experienced FEV1 decline>100 mL/year were deemed “decliners,” while those who did not were deemed “sustainers.” Nonimaging and imaging prediction models were generated through a logistic regression model, which utilized measurements from sustainers and decliners.ResultsThe nonimaging prediction model included the St. George Respiratory Questionnaire total score, diffusing capacity of carbon monoxide by the alveolar volume (DLCO/VA), and distance walked in a six-minute walk test. A receiving operating character curve for this model yielded a sensitivity of 75% and specificity of 68% with an overall area under the curve of 65%. The imaging prediction model generated following the same methodology included ADCH, FVH, and PAO2H. The resulting receiving operating character curve yielded a sensitivity of 87.5%, specificity of 82.8%, and an area under the curve of 89.7%.ConclusionThe imaging predication model generated from measurements obtained during 3He MR imaging is better able to predict future FEV1 decline compared to one based on current clinical tests and demographics. The imaging model's superiority appears to arise from its ability to distinguish well-circumscribed, severe disease from a more uniform distribution of moderately altered lung function, which is more closely associated with subsequent FEV1 decline.
       
  • Using Hyperpolarized Xenon-129 MRI to Quantify Early-Stage Lung Disease in
           Smokers
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Kai Ruppert, Kun Qing, James T. Patrie, Talissa A. Altes, John P. MuglerRationale and ObjectivesHyperpolarized xenon-129 magnetic resonance (MR) provides sensitive tools that may detect early stages of lung disease in smokers before it has progressed to chronic obstructive pulmonary disease (COPD) apparent to conventional spirometric measures. We hypothesized that the functional alveolar wall thickness as assessed by hyperpolarized xenon-129 MR spectroscopy would be elevated in clinically healthy smokers before xenon MR diffusion measurements would indicate emphysematous tissue destruction.Materials and MethodsUsing hyperpolarized xenon-129 MR we measured the functional septal wall thickness and apparent diffusion coefficient of the gas phase in 16 subjects with smoking-related COPD, 9 clinically healthy current or former smokers, and 10 healthy never smokers. All subjects were age-matched and characterized by conventional pulmonary function tests. A total of 11 data sets from younger healthy never smokers were added to determine the age dependence of the septal wall thickness measurements.ResultsIn healthy never smokers the septal wall thickness increased by 0.04 μm per year of age. The healthy smoker cohort exhibited normal pulmonary function test measures that did not significantly differ from the never-smoker cohort. The age-corrected septal wall thickness correlated well with diffusion capacity for carbon monoxide (R2 = 0.56) and showed a highly significant difference between healthy subjects and COPD patients (8.8 μm vs 12.3 μm; p < 0.001), but was the only measure that actually discriminated healthy subjects from healthy smokers (8.8 μm vs 10.6 μm; p < 0.006).ConclusionFunctional alveolar wall thickness assessed by hyperpolarized xenon-129 MR allows discrimination between healthy subjects and healthy smokers and could become a powerful new measure of early-stage lung disease.
       
  • Hyperpolarized Gas Magnetic Resonance Imaging of Pediatric Cystic Fibrosis
           Lung Disease
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Giles Santyr, Nikhil Kanhere, Felipe Morgado, Jonathan H. Rayment, Felix Ratjen, Marcus J. CouchConventional pulmonary function tests appear normal in early cystic fibrosis (CF) lung disease. Therefore, new diagnostic approaches are required that can detect CF lung disease in children and monitor treatment response. Hyperpolarized (HP) gas (129Xe and 3He) magnetic resonance imaging (MRI) is a powerful, emergent tool for mapping regional lung function and may be well suited for studying pediatric CF. HP gas MRI is well tolerated, reproducible, and it can be performed longitudinally without the need for ionizing radiation. In particular, quantification of the distribution of ventilation, or ventilation defect percent (VDP), has been shown to be a sensitive indicator of CF lung disease and correlates well with pulmonary function tests.This article presents the current state of CF diagnosis and treatment and describes the potential role of HP gas MRI for detection of early CF lung disease and following the effects of interventions. The typical HP gas imaging workflow is described, along with a discussion of image analysis to calculate VDP, dosing considerations, and the reproducibility of VDP.The potential use of VDP as an outcome measure in CF is discussed, by considering the correlation with pulmonary function measures, preliminary interventional studies, and case studies involving longitudinal imaging and pulmonary exacerbations.Finally, emerging HP gas imaging techniques such as multiple breath washout imaging are introduced, followed by a discussion of future directions. Overall, HP gas MRI biomarkers are expected to provide sensitive outcome measures that can be used in disease surveillance as well as interventional studies involving novel CF therapies.
       
  • Current Advances in COPD Imaging
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Jeffrey Thiboutot, Wu Yuan, Hyeon-Cheol Park, Andrew D Lerner, Wayne Mitzner, Lonny B Yarmus, Xingde Li, Robert H. BrownObjectiveTo review the recent advances in available technologies for imaging COPD and present the novel optical coherence tomography (OCT) airway imaging technology.Materials and MethodsThis is an unstructured review of published evidence of available pulmonary imaging technologies along with a demonstration of state-of-the-art OCT imaging technology of in vivo human and animal airways.ResultsAdvanced imaging techniques such as Magnetic Resonance (MR) imaging using hyperoloarized noble gases, micro-Computed Tomography (micro-CT), and OCT aim to further our understanding of COPD. Lung densitometry can aid in identifying an exacerbation prone phenotype which may have implications for targeting specific therapies to these individuals. MR ventilation scans have the ability to provide a functional and regional distribution of airflow obstruction offering insight into the airway and parenchymal changes induced by COPD. Micro-CT gives a near microscopic view of the terminal bronchioles and alveoli permitting study of the microarchitecture of the lung ex vivo. Optical coherence tomography can visualize the microstructure of the airway walls (epithelium, smooth muscle, blood vessels, cartilage) permitting real time in vivo as well as longitudinal evaluation of airway changes in patients with COPD.ConclusionAdvanced imaging techniques play a vital role in expanding our current understanding of COPD.
       
  • Probing Changes in Lung Physiology in COPD Using CT, Perfusion MRI, and
           Hyperpolarized Xenon-129 MRI
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Kun Qing, Nicholas J. Tustison, John P. Mugler, Jaime F. Mata, Zixuan Lin, Li Zhao, Da Wang, Xue Feng, Ji Young Shin, Sean J. Callahan, Michael P. Bergman, Kai Ruppert, Talissa A. Altes, Joanne M. Cassani, Y. Michael ShimRationale and ObjectivesChronic obstructive pulmonary disease (COPD) is highly heterogeneous and not well understood. Hyperpolarized xenon-129 (Xe129) magnetic resonance imaging (MRI) provides a unique way to assess important lung functions such as gas uptake. In this pilot study, we exploited multiple imaging modalities, including computed tomography (CT), gadolinium-enhanced perfusion MRI, and Xe129 MRI, to perform a detailed investigation of changes in lung morphology and functions in COPD. Utility and strengths of Xe129 MRI in assessing COPD were also evaluated against the other imaging modalities.Materials and MethodsFour COPD patients and four age-matched normal subjects participated in this study. Lung tissue density measured by CT, perfusion measures from gadolinium-enhanced MRI, and ventilation and gas uptake measures from Xe129 MRI were calculated for individual lung lobes to assess regional changes in lung morphology and function, and to investigate correlations among the different imaging modalities.ResultsNo significant differences were found for all measures among the five lobes in either the COPD or age-matched normal group. Strong correlations (R> 0.5 or < −0.5, p < 0.001) were found between ventilation and perfusion measures. Also gas uptake by blood as measured by Xe129 MRI showed strong correlations with CT tissue density and ventilation measures (R> 0.5 or < −0.5, p < 0.001) and moderate to strong correlations with perfusion measures (R> 0.4 or < −0.5, p < 0.01). Four distinctive patterns of functional abnormalities were found in patients with COPD.ConclusionXe129 MRI has high potential to uniquely identify multiple changes in lung physiology in COPD using a single breath-hold acquisition.
       
  • Spatial Heterogeneity of Lung Strain and Aeration and Regional
           Inflammation During Early Lung Injury Assessed with PET/CT
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Gabriel Motta-Ribeiro, Tilo Winkler, Soshi Hashimoto, Marcos F. Vidal MeloIntroductionSpatial heterogeneity of lung aeration and strain (change volume/resting volume) occurs at microscopic levels and contributes to lung injury. Yet, it is mostly assessed with histograms or large regions-of-interest. Spatial heterogeneity could also influence regional gene expression. We used positron emission tomography (PET)/computed tomography (CT) to assess the contribution of different length-scales to mechanical heterogeneity and to direct lung injury biological pathway identification.Materials and MethodsSheep exposed to mild (n = 5, supine and n = 3, prone) and moderate (n = 6, supine) systemic endotoxemia were protectively ventilated. At baseline, 6 hours and 20 hours length-scale analysis was applied to aeration in CT (mild groups) and PET transmission (moderate group) scans; and voxel-level strain derived from image registration of end-inspiratory and end-expiratory CTs (mild). 2-deoxy-2-[(18)F]fluoro-d-glucose (18F-FDG)-PET kinetics parameters in ventral and dorsal regions were correlated with tissue microarray gene expression (moderate).ResultsWhile aeration and strain heterogeneity were highest at 5–10 mm length-scales, larger length-scales contained a higher fraction of strain than aeration heterogeneity. Contributions of length-scales>5–10 mm to aeration and strain heterogeneity increased as lung injury progressed (p < 0.001) and were higher in supine than prone animals. Genes expressed with regional correlation to 18F-FDG-PET kinetics ( r  = 0.81 [0.78–0.85]) yielded pathways associated with immune system activation and fluid clearance.ConclusionNormal spatial heterogeneity of aeration and strain suggest larger anatomical and functional determinants of lung strain than aeration heterogeneity. Lung injury and supine position increase the contribution of larger length-scales. 18F−FDG-PET-based categorization of gene expression results in known and novel biological pathways relevant to lung injury.
       
  • Convolutional Neural Networks with Template-Based Data Augmentation for
           Functional Lung Image Quantification
    • Abstract: Publication date: March 2019Source: Academic Radiology, Volume 26, Issue 3Author(s): Nicholas J. Tustison, Brian B. Avants, Zixuan Lin, Xue Feng, Nicholas Cullen, Jaime F. Mata, Lucia Flors, James C. Gee, Talissa A. Altes, John P. Mugler, III, Kun QingRationale and ObjectivesWe propose an automated segmentation pipeline based on deep learning for proton lung MRI segmentation and ventilation-based quantification which improves on our previously reported methodologies in terms of computational efficiency while demonstrating accuracy and robustness. The large data requirement for the proposed framework is made possible by a novel template-based data augmentation strategy. Supporting this work is the open-source ANTsRNet—a growing repository of well-known deep learning architectures first introduced here.Materials and MethodsDeep convolutional neural network (CNN) models were constructed and trained using a custom multilabel Dice metric loss function and a novel template-based data augmentation strategy. Training (including template generation and data augmentation) employed 205 proton MR images and 73 functional lung MRI. Evaluation was performed using data sets of size 63 and 40 images, respectively.ResultsAccuracy for CNN-based proton lung MRI segmentation (in terms of Dice overlap) was left lung: 0.93 ± 0.03, right lung: 0.94 ± 0.02, and whole lung: 0.94 ± 0.02. Although slightly less accurate than our previously reported joint label fusion approach (left lung: 0.95 ± 0.02, right lung: 0.96 ± 0.01, and whole lung: 0.96 ± 0.01), processing time is
       
  • Improvement of Cancer Detection on Mammograms via BREAST Test Sets
    • Abstract: Publication date: Available online 28 February 2019Source: Academic RadiologyAuthor(s): Phuong Dung (Yun) Trieu, Kriscia Tapia, Helen Frazer, Warwick Lee, Patrick BrennanBackgroundBreast Screen Reader Assessment Strategy (BREAST) is an innovative training and research program for radiologists in Australia and New Zealand. The aim of this study is to evaluate the efficacy of BREAST test sets in improving readers’ performance in detecting cancers on mammograms.Materials and MethodsBetween 2011 and 2018, 50 radiologists (40 fellows, 10 registrars) completed three BREAST test sets and 17 radiologists completed four test sets. Each test set contained 20 biopsy-proven cancer and 40 normal cases. Immediate image-based feedback was available to readers after they completed each test set which allowed the comparison of their selections with the truth. Case specificity, case sensitivity, lesion sensitivity, the Receiver Operating Characteristic (ROC) Area Under the Curve (AUC) and Jackknife Free-Response Receiver Operating Characteristic (JAFROC) Figure of Merit (FOM) were calculated for each reader. Kruskal–Wallis test was utilized to compare scores of the radiologist and registrars across all test-sets whilst Wilcoxon signed rank test was to compare the scores between pairs of test sets.ResultsSignificant improvements in lesion sensitivity ranging from 21% to 31% were found in radiologists completing later test sets compared to first test set (p ≤ 0.01). Eighty three percent of radiologists achieved higher performance in lesion sensitivity after they completed the first read. Registrars had significantly better scores in the third test set compared to the first set with mean increases of 79% in lesion sensitivity (p = 0.005) and 37% in JAFROC (p = 0.02). Sixty percent and 100% of registrars increased their scores in lesion sensitivity in the second and third reads compared to the first read while the percentage of registrars with higher scores in JAFROC was 80%.ConclusionIntroduction of BREAST into national training programs appears to have an important impact in promoting diagnostic efficacy amongst radiologists and radiology registrars undergoing mammographic readings.
       
  • Regional Differences in Budd-Chiari Syndrome and the Role of Spectral CT
           for the Assessment of Therapeutic Response
    • Abstract: Publication date: Available online 26 February 2019Source: Academic RadiologyAuthor(s): William R. Masch
       
  • Spectral CT Imaging in the Differential Diagnosis of Small Bowel
           Adenocarcinoma From Primary Small Intestinal Lymphoma
    • Abstract: Publication date: Available online 22 February 2019Source: Academic RadiologyAuthor(s): Chuang-bo Yang, Nan Yu, Yong-jun Jian, Yong Yu, Hai-feng Duan, Xi-rong Zhang, Guang-ming Ma, Youmin Guo, Xiaoyi DuanPurposeTo investigate the value of dual-energy spectral computed tomography (CT) imaging in the differential diagnosis of small bowel adenocarcinoma (SBA) from primary small intestinal lymphoma (PSIL).Materials and MethodsWe retrospectively analyzed the images of 27 SBA cases and 15 PSIL cases. These patients underwent spectral CT imaging in the arterial phase (AP) and venous phase (VP). CT attenuation values of tumors at different energy levels were measured to generate spectral attenuation curve and to calculate curve slope (λHU). Iodine concentration (IC) in tumors at AP and VP were measured and normalized to that of aorta as normalized iodine concentration (NIC). Independent samples t test was used to analyze the spectral CT parameters; Receiver operating characteristic curves were generated to evaluate the diagnostic efficacy of each parameter.ResultsThere were significant differences between SBA and PSIL in IC (2.09 ± 0.71 vs 1.33 ± 0.15 mg/ml), NIC (0.20 ± 0.06 vs 0.13 ± 0.02) and slope (λHU) (2.78 ± 1.06 vs 1.86 ± 0.30) in AP and (1.86 ± 0.68 vs 1.37 ± 0.18 mg/ml for IC; 0.47 ± 0.13 vs 0.33 ± 0.02 for NIC and 2.00 ± 0.56 vs 1.50 ± 0.26 for λHU) in VP (all p < 0.05). For the CT value measurement, there were significant differences between SBA and PSIL in the 40–60keV energy range (p < 0.05), but not in the 70–140keV range (p> 0.05). Using 1.38 mg/ml as a threshold value for iodine concentration at AP, one could obtain the area-under-curve of 0.93 for receiver operating characteristic study and sensitivity of 94% and specificity of 85% for differentiating SBA from PSIL. The sensitivity and specificity values were significantly higher than the respective values of 62% and 60% with the conventional CT numbers at 70keV.ConclusionQuantitative parameters obtained in spectral CT, especially iodine concentration in AP, provide high accuracy for differentiating SBA from PSIL.
       
  • Influence of Monoenergetic Images at Different Energy Levels in
           Dual-Energy Spectral CT on the Accuracy of Computer-Aided Detection for
           Pulmonary Embolism
    • Abstract: Publication date: Available online 22 February 2019Source: Academic RadiologyAuthor(s): Guangming Ma, Yuequn Dou, Shan Dang, Nan Yu, Yanbing Guo, Chuangbo Yang, Shuanhong Lu, Dong Han, Chenwang JinPurposeTo investigate the influence of monoenergetic images of different energy levels in spectral computed tomography (CT) on the accuracy of computer aided detection (CAD) for pulmonary embolism (PE).Materials and MethodsCT images of 20 PE patients who underwent spectral CT pulmonary angiography were retrospectively analyzed. Nine sets of monochromatic images from 40 to 80 keV at 5 keV interval were reconstructed and then independently analyzed for detecting PE using a commercially available CAD software. Two experienced radiologists reviewed all images and recorded the number of emboli manually, which was used as the reference standard. The CAD findings for the number of PE at different energies were compared with the reference standard to determine the number of true positives and false positives with CAD and to calculate the sensitivity and false positive rate at different energies.ResultThere were 120 true emboli. The total numbers of CAD-detected PE at 40–80 keV were 48, 67, 63, 87, 106, 115, 138, 157, and 226. Images at low energies had low sensitivities and low false positive rates; images at high energies had high sensitivities and high false positive rates. At 60 keV and 65 keV, CAD achieved sensitivity at 81.67% and 84.17%, respectively and false positive rate at 7.55% and 12.17%, respectively to provide the optimum combination of high sensitivity and low false positive rate.ConclusionMonochromatic images of different energies in dual-energy spectral CT affect the accuracy of CAD for PE. The combination of CAD with images at 60–65 keV provides the optimum combination of high sensitivity and low false positive rate in detecting PE.
       
  • Reprint of: Voxel-Wise Longitudinal Parametric Response Mapping Analysis
           of Chest Computed Tomography in Smokers
    • Abstract: Publication date: Available online 18 February 2019Source: Academic RadiologyAuthor(s): Wassim W. Labaki, Tian Gu, Susan Murray, Charles R. Hatt, Craig J. Galbán, Brian D. Ross, Carlos H. Martinez, Jeffrey L. Curtis, Eric A. Hoffman, Esther Pompe, David A. Lynch, Ella A. Kazerooni, Fernando J. Martinez, MeiLan K. HanRationale and ObjectivesChronic obstructive pulmonary disease is a heterogeneous disease characterized by small airway abnormality and emphysema. We hypothesized that a voxel-wise computed tomography analytic approach would identify patterns of disease progression in smokers.Materials and MethodsWe analyzed 725 smokers in spirometric GOLD stages 0-4 with two chest CTs 5 years apart. Baseline inspiration, follow-up inspiration and follow-up expiration images were spatially registered to baseline expiration so that each voxel had correspondences across all time points and respiratory phases. Voxel-wise Parametric Response Mapping (PRM) was then generated for the baseline and follow-up scans. PRM classifies lung as normal, functional small airway disease (PRMfSAD), and emphysema (PRMEMPH).ResultsSubjects with low baseline PRMfSAD and PRMEMPH predominantly had an increase in PRMfSAD on follow-up; those with higher baseline PRMfSAD and PRMEMPH mostly had increases in PRMEMPH. For GOLD 0 participants (n = 419), mean 5-year increases in PRMfSAD and PRMEMPH were 0.3% for both; for GOLD 1–4 participants (n = 306), they were 0.6% and 1.6%, respectively. Eighty GOLD 0 subjects (19.1%) had overall radiologic progression (30.0% to PRMfSAD, 52.5% to PRMEMPH, and 17.5% to both); 153 GOLD 1–4 subjects (50.0%) experienced progression (17.6% to PRMfSAD, 48.4% to PRMEMPH, and 34.0% to both). In a multivariable model, both baseline PRMfSAD and PRMEMPH were associated with development of PRMEMPH on follow-up, although this relationship was diminished at higher levels of baseline PRMEMPH.ConclusionA voxel-wise longitudinal PRM analytic approach can identify patterns of disease progression in smokers with and without chronic obstructive pulmonary disease.
       
  • Radiology's Role in Public Health Education About Obesity
    • Abstract: Publication date: Available online 16 February 2019Source: Academic RadiologyAuthor(s): Evan M Rush, Richard B Gunderman
       
  • Comparison of 2D BLADE Turbo Gradient- and Spin-Echo and 2D Spin-Echo
           Echo-Planar Diffusion-Weighted Brain MRI at 3 T: Preliminary Experience in
           Children
    • Abstract: Publication date: Available online 15 February 2019Source: Academic RadiologyAuthor(s): Houchun H. Hu, Aaron S. McAllister, Ning Jin, Lacey J. Lubeley, Bhavani Selvaraj, Mark Smith, Ramkumar Krishnamurthy, Kun ZhouRationale and ObjectivesWe describe our preliminary experience using a 2D turbo gradient- and spin-echo (TGSE) diffusion-weighted (DW) pulse sequence with non-Cartesian BLADE trajectory at 3 T in pediatric patients. We compared the TGSE BLADE to conventional DW spin-echo echo-planar imaging (SE-EPI) in pediatric brain imaging, assessing the presence of artifacts from signal pile-ups, geometric distortion, motion, susceptibility from air-tissue interface, shunts and orthodontia, and diagnostic image quality.Materials and MethodsData were acquired in 53 patients (10.4 ± 7.9 years). All DW imaging data were acquired precontrast, with SE-EPI first. A four-point scale for rating was used—1 (best) and 4 (worst). A neuroradiologist scored the two sequences and further noted whether the TGSE BLADE approach or SE-EPI was preferred in each case. Apparent diffusion coefficients were compared quantitatively between the two sequences in a subset of 16 patients, in 41 separate regions of interests including caudate nucleus, putamen, globus pallidus, thalamus, and pathological areas.ResultsIn 43.4% of the cases, TGSE BLADE was preferred; in 49.1% of the cases, both sequences were preferred equally. Average scores for SE-EPI were 2.2 ± 0.8 versus TGSE's 1.2 ± 0.4 in assessing diagnostic quality (p < 0.05). Motion artifacts were minimal on both sequences in 92.5% of the cases. In the TGSE BLADE scores, no case received a “4” for significant artifacts with marginally acceptable image quality. Apparent diffusion coefficients values between the two sequences were statistically similar, with a linear regression slope of 0.92 (r2 = 0.97).ConclusionTGSE BLADE DW imaging exhibited less geometric distortion in the brain and reduced signal pile-ups in areas of high susceptibility than conventional SE-EPI.
       
  • Prognostic Value of the Pretreatment Primary Lesion Quantitative Dynamic
           
    • Abstract: Publication date: Available online 14 February 2019Source: Academic RadiologyAuthor(s): Yuhui Qin, Xiaoping Yu, Jing Hou, Ying Hu, Feiping Li, Lu Wen, Qiang Lu, Siye LiuRationale and ObjectivesEarly identifying the long-term outcome of chemoradiotherapy is helpful for personalized treatment in nasopharyngeal carcinoma (NPC). This study aimed to investigate the prognostic significance of pretreatment quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for NPC.Materials and MethodsThe relationships between the prognosis and pretreatment quantitative DCE-MRI (Ktrans, Kep, Ve, and fpv) values of the primary tumors were analyzed in 134 NPC patients who received chemoradiotherapy. Kaplan-Meier analysis was performed to calculate the local-regional relapse-free survival (LRRFS), local relapse-free survival (LRFS), regional relapse-free survival, distant metastasis-free survival (DMFS), progression-free survival, and overall survival rates. Cox proportional hazards model was used to explore the independent predictors for prognosis.ResultsThe local-failure group had significantly higher Ve (p = 0.033) and fpv values (p = 0.005) than the non-local-failure group. The Ve-high group showed significantly lower LRRFS (p = 0.015) , LRFS (p = 0.013) , DMFS (p = 0.027) and progression-free survival (p = 0.035) rates than the Ve-low group. The fpv-high group exhibited significantly lower LRRFS (p = 0.004) and LRFS (p = 0.005) rates than the fpv-low group. Ve was the independent predictor for LRRFS (p = 0.008), LRFS (p = 0.007), DMFS (p = 0.041), and overall survival (p = 0.022). fpv was the independent indicator for LRRFS (p = 0.003) and LRFS (p = 0.001).ConclusionBaseline quantitative DCE-MRI may be valuable in predicting the prognosis for NPC.
       
  • Perception's Crucial Role in Radiology Education
    • Abstract: Publication date: Available online 14 February 2019Source: Academic RadiologyAuthor(s): Richard B. Gunderman, Parth Patel
       
  • Discrimination Between Solitary Brain Metastasis and Glioblastoma
           Multiforme by Using ADC-Based Texture Analysis: A Comparison of Two
           Different ROI Placements
    • Abstract: Publication date: Available online 12 February 2019Source: Academic RadiologyAuthor(s): Guoqin Zhang, Xin Chen, Sijing Zhang, Xiuhang Ruan, Cuihua Gao, Zaiyi Liu, Xinhua WeiRationale and ObjectivesTo explore the value of texture analysis based on the apparent diffusion coefficient (ADC) value and the effect of region of interest (ROI) placements in distinguishing glioblastoma multiforme (GBM) from solitary brain metastasis (sMET).Materials and MethodsSixty-two patients with pathologically confirmed GBM (n = 36) and sMET (n = 26) were retrospectively included. All patients underwent diffusion-weighted imaging with b values of 0 and 1000 s/mm2, and the ADC maps were generated automatically. ROIs were placed on the largest whole single-slice tumor (ROI1) and the enhanced solid portion (ROI2) of the ADC maps, respectively. The texture feature metrics of the histogram and gray-level co-occurrence matrix were then extracted by using in-house software. The parameters of the texture analysis were compared between GBM and sMET, using the Mann–Whitney U test. A receiver operating characteristic (ROC) curve analysis was performed to determine the best parameters for distinguishing between GBM from sMET.ResultsHomogeneity and the inverse difference moment (IDM) of GBM were significantly higher than those of sMET in both ROIs (ROI1, p = 0.014 for homogeneity and p = 0.048 for IDM; ROI2, p 0.05).ConclusionThe ADC-based texture analysis can help differentiate GBM from sMET, and the ROI on the solid portion would be recommended to calculate the ADC-based texture metrics.
       
  • Gestalt Theory in Education and Practice
    • Abstract: Publication date: Available online 11 February 2019Source: Academic RadiologyAuthor(s): Mert Sirakaya
       
  • Coronary CT Angiography in Challenging Patients: High Heart Rate and
           Atrial Fibrillation. A Review
    • Abstract: Publication date: Available online 10 February 2019Source: Academic RadiologyAuthor(s): Saima Mushtaq, Edoardo Conte, Eleonora Melotti, Daniele AndreiniDespite several strategies have been developed by different vendors to improve image quality and diagnostic accuracy of coronary CT angiography performed at high heart rate (HR) and HR variability, as in patients with atrial fibrillation (AF), some concerns and small clinical experience characterize these subsets of challenging patients. However, patients with AF have been reported to have higher risk of cardiovascular events and noninvasive evaluation of suspected coronary artery disease in this setting may be of extreme clinical interest. The goal of this review is to provide to the reader an overview on the use of cardiac CT in patients with AF and high HR and to outline the technological improvements recently introduced in the clinical field that may enable to definitively overcome the limitations of cardiac CT in this challenging scenario.
       
  • The Baader-Meinhof Phenomenon in Radiology
    • Abstract: Publication date: Available online 7 February 2019Source: Academic RadiologyAuthor(s): Kush Purohit
       
  • Mammographic Breast Density: More than Meets the Eye
    • Abstract: Publication date: Available online 7 February 2019Source: Academic RadiologyAuthor(s): Victoria L. Mango
       
  • Response to: Accuracy of Breast MRI Compared to MG in the Preoperative
           Detection and Measurement of Pure Ductal Carcinoma In Situ: A
           Methodological Issue
    • Abstract: Publication date: Available online 6 February 2019Source: Academic RadiologyAuthor(s): Heike Preibsch, Gunnar Blumenstock
       
  • Patient-Centered and Specialty-Specific Case Work-Up: An Effective Method
           for Teaching Appropriateness of Imaging to Medical Students
    • Abstract: Publication date: Available online 5 February 2019Source: Academic RadiologyAuthor(s): Mike Sheng, Preya Shah, John M. Choi, Eleanor Gillis, Sharyn I. Katz, Scott A. Simpson, Sean H. Novak, Arun C. NachiappanRationale and ObjectivesOur institution has developed a mini-course program within the diagnostic radiology elective curriculum that promotes active learning, using patient cases specifically tailored to students’ future specialties. The purpose of this study is to evaluate the effectiveness of this mini-course on medical student knowledge of imaging appropriateness and attitude toward radiologist consultation.Materials and MethodsDuring each month-long radiology elective course, students were divided into teams of up to four students based on their specialty interest and assigned recent patient cases with imaging findings relevant to their specialties. The students researched their customized patient cases, integrated pertinent clinical and imaging findings, and presented their findings in a final preceptor-led session. A five-point Likert-type item preprogram and postprogram survey assessing knowledge of imaging appropriateness and attitude toward radiologist consultation was sent to the enrolled medical students.ResultsOut of 36 medical students, 33 (92%) completed the preprogram survey and 31 (86%) completed the postprogram survey. Students reported improved confidence in knowledge of imaging appropriateness, such as indications for intravenous contrast (p < 0.0005) and oral contrast (p < 0.0005). Furthermore, students reported an improved understanding of how to utilize radiologists (p < 0.005) and how to provide pertinent clinical historical information when requesting a radiology exam (p < 0.0005). Students reported that researching the patient's historical and clinical information in conjunction with the radiology images made them more invested in the case.ConclusionAssigning customized patient cases to medical students on diagnostic radiology elective, tailored to their future specialties, is an effective and active way to teach imaging appropriateness and to improve attitudes toward radiologist consultation.
       
  • Recruiting Medical Students to Interventional Radiology: Current State of
           Affairs
    • Abstract: Publication date: Available online 4 February 2019Source: Academic RadiologyAuthor(s): Juri Bassuner, David Duncan, Chris Malloy, Mina Makary, Brycen Bodell, Dylan Assael, Riz Ahmed, Geogy VatakancherryObjectiveInterventional 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.
       
  • Risk Assessment of Intracranial Aneurysms with MRI
    • Abstract: Publication date: Available online 4 February 2019Source: Academic RadiologyAuthor(s): Masaaki Hori, Shohei Fujita
       
  • RE: A Methodological Issue in Prediction of Cancer Masking in Screening
           Mammography Using Density and Textural Features - Authors’ Response
    • Abstract: Publication date: Available online 31 January 2019Source: Academic RadiologyAuthor(s): James G. Mainprize, Olivier Alonzo-Proulx, Taghreed Alshafeiy, James T. Patrie, Jennifer A. Harvey, Martin J. Yaffe
       
  • Accuracy of Breast MRI Compared to MG in the Preoperative Detection and
           Measurement of Pure Ductal Carcinoma In Situ: A Methodological Issue
    • Abstract: Publication date: Available online 31 January 2019Source: Academic RadiologyAuthor(s): Soodeh Shahsavari
       
  • Automatic Breast and Fibroglandular Tissue Segmentation in Breast MRI
           Using Deep Learning by a Fully-Convolutional Residual Neural Network U-Net
           
    • Abstract: Publication date: Available online 31 January 2019Source: Academic RadiologyAuthor(s): Yang Zhang, Jeon-Hor Chen, Kai-Ting Chang, Vivian Youngjean Park, Min Jung Kim, Siwa Chan, Peter Chang, Daniel Chow, Alex Luk, Tiffany Kwong, Min-Ying SuRationale and ObjectivesBreast segmentation using the U-net architecture was implemented and tested in independent validation datasets to quantify fibroglandular tissue volume in breast MRI.Materials and MethodsTwo datasets were used. The training set was MRI of 286 patients with unilateral breast cancer. The segmentation was done on the contralateral normal breasts. The ground truth for the breast and fibroglandular tissue (FGT) was obtained by using a template-based segmentation method. The U-net deep learning algorithm was implemented to analyze the training set, and the final model was obtained using 10-fold cross-validation. The independent validation set was MRI of 28 normal volunteers acquired using four different MR scanners. Dice Similarity Coefficient (DSC), voxel-based accuracy, and Pearson's correlation were used to evaluate the performance.ResultsFor the 10-fold cross-validation in the initial training set of 286 patients, the DSC range was 0.83–0.98 (mean 0.95 ± 0.02) for breast and 0.73–0.97 (mean 0.91 ± 0.03) for FGT; and the accuracy range was 0.92–0.99 (mean 0.98 ± 0.01) for breast and 0.87–0.99 (mean 0.97 ± 0.01) for FGT. For the entire 224 testing breasts of the 28 normal volunteers in the validation datasets, the mean DSC was 0.86 ± 0.05 for breast, 0.83 ± 0.06 for FGT; and the mean accuracy was 0.94 ± 0.03 for breast and 0.93 ± 0.04 for FGT. The testing results for MRI acquired using four different scanners were comparable.ConclusionDeep learning based on the U-net algorithm can achieve accurate segmentation results for the breast and FGT on MRI. It may provide a reliable and efficient method to process large number of MR images for quantitative analysis of breast density.
       
  • Growing Interest in Radiology Despite AI Fears
    • Abstract: Publication date: Available online 31 January 2019Source: Academic RadiologyAuthor(s): Kush Purohit
       
  • A Methodological Issue in Prediction of Cancer Masking in Screening
           Mammography Using Density and Textural Features
    • Abstract: Publication date: Available online 30 January 2019Source: Academic RadiologyAuthor(s): Sara Jambarsang, Seyyed Mohammad Tabatabaei, Ronak Ahmadi
       
  • The Resident Travel Dilemma
    • Abstract: Publication date: Available online 30 January 2019Source: Academic RadiologyAuthor(s): Cory M. Pfeifer
       
  • Contrast Enhancement Boost Technique at Aortic Computed Tomography
           Angiography: Added Value for the Evaluation of Type II Endoleaks After
           Endovascular Aortic Aneurysm Repair
    • Abstract: Publication date: Available online 30 January 2019Source: Academic RadiologyAuthor(s): Hitoshi Iizuka, Yasuhiro Yokota, Masafumi Kidoh, Seitaro Oda, Osamu Ikeda, Yoshitaka Tamura, Yoshinori Funama, Daisuke Sakabe, Takeshi Nakaura, Yasuyuki Yamashita, Daisuke UtsunomiyaRationale and ObjectivesDelayed-phase acquisition of the computed tomography (CT) angiography is important for the evaluation of type II endoleaks after endovascular aortic aneurysm repair because the endoleak cavity area is associated with aneurysm sac expansion. Contrast enhancement boost (CE-boost) is a postprocessing technique for increasing the degree of contrast enhancement on contrast-enhanced CT. We aimed to investigate the usefulness of the CE-boost technique for the visualization of type II endoleaks.Materials and MethodsThis retrospective study included 28 patients with type II endoleaks after endovascular aortic aneurysm repair who underwent triphasic contrast-enhanced CT. Objective (CT number, signal-to-noise ratio, and contrast-to-noise ratio) and subjective quality analyses using a four-point scale (1, poor; 4, excellent) were performed for the conventional early- and delayed-phase images as well as CE-boost delayed-phase images.ResultsThe CE-boost delayed-phase images yielded a significantly higher CT number (134.5 ± 41.7 HU), signal-to-noise ratio (23.4 ± 10.5), and contrast-to-noise ratio (15.3 ± 8.4) and showed a significantly larger endoleak area (145.0 ± 134.8 mm2) than did the conventional early-phase (95.6 ± 53.2 HU, 7.3 ± 4.7, 4.0 ± 4.2, and 56.2 ± 99.3 mm2, respectively) and delayed-phase (110.5 ± 33.3 HU, 8.2 ± 2.7, 4.9 ± 2.0, and 124.8 ± 131.9 mm2, respectively) images (p < 0.01). The endoleak visibility score was highest for the CE-boost delayed-phase images (2.0 ± 1.0, 3.0 ± 0.6, and 3.4 ± 0.7 for conventional early-phase, delayed-phase, and delayed-phase CE-boost images, respectively; p < 0.001).ConclusionThe CE-boost technique facilitates clear visualization of type II endoleak cavities.
       
  • Radiological Advances in Pancreatic Islet Transplantation
    • Abstract: Publication date: Available online 30 January 2019Source: Academic RadiologyAuthor(s): Donal Cahill, Fernanda Zamboni, Maurice N. CollinsType 1 diabetes mellitus (T1DM) is characterized by hyperglycemia, owing to the loss of pancreatic β cells in response to an autoimmune reaction leading to a state of absolute insulin deficiency. T1DM treatment is shifting from exogenous insulin replacement therapy toward pancreatic β-cell replacement, to restore physiologically responsive insulin secretion to variations in blood glucose levels. β-cell replacement strategies include human whole pancreas transplantation, islet transplantation with cell encapsulation and bioengineered pancreas. Interventional radiology and imaging modalities including positron emission tomography, single-photon emission computed tomography, magnetic resonance imaging, ultrasonography, and molecular imaging are imperative to enable successful β-cell replacement. Herein, the role of radiological modalities in the treatment of T1DM and its prospective use for noninvasive post-transplantation graft monitoring is discussed.
       
  • Not the Time for Complacency
    • Abstract: Publication date: Available online 30 January 2019Source: Academic RadiologyAuthor(s): Bo Gong, James P. Nugent, William Guest, William Parker, Paul J. Chang, Faisal Khosa, Savvas Nicolaou
       
  • Machine Learning-based Analysis of Rectal Cancer MRI Radiomics for
           Prediction of Metachronous Liver Metastasis
    • Abstract: Publication date: Available online 30 January 2019Source: Academic RadiologyAuthor(s): Meng Liang, Zhengting Cai, Hongmei Zhang, Chencui Huang, Yankai Meng, Li Zhao, Dengfeng Li, Xiaohong Ma, Xinming ZhaoRationale and ObjectivesTo use machine learning-based magnetic resonance imaging radiomics to predict metachronous liver metastases (MLM) in patients with rectal cancer.Materials and MethodsThis study retrospectively analyzed 108 patients with rectal cancer (54 in MLM group and 54 in nonmetastases group). Feature selection were performed in the radiomic feature sets extracted from images of T2-weighted image (T2WI) and venous phase (VP) sequence respectively, and the combining feature set with 2058 radiomic features incorporating two sequences with the least absolute shrinkage and selection operator method. Five-fold cross-validation and two machine learning algorithms (support vector machine [SVM]; logistic regression [LR]) were utilized for predictive model constructing. The diagnostic performance of the models was evaluated by receiver operating characteristic curves with indicators of accuracy, sensitivity, specificity and area under the curve, and compared by DeLong test.ResultsFive, 8, and 22 optimal features were selected from 1029 T2WI, 1029 VP, and 2058 combining features, respectively. Four-group models were constructed using the five T2WI features (ModelT2), the 8 VP features (ModelVP), the combined 13 optimal features (Modelcombined), and the 22 optimal features selected from 2058 features (Modeloptimal). In ModelVP, the LR was superior to the SVM algorithm (P = 0.0303). The Modeloptimal using LR algorithm showed the best prediction performance (P = 0.0019–0.0081) with accuracy, sensitivity, specificity, and area under the curve of 0.80, 0.83, 0.76, and 0.87, respectively.ConclusionRadiomics models based on baseline rectal magnetic resonance imaging has high potential for MLM prediction, especially the Modeloptimal using LR algorithm. Moreover, except for ModelVP, the LR was not superior to the SVM algorithm for model construction.
       
  • Artificial Intelligence in Radiology: Resident Recruitment Help or
           Hindrance'
    • Abstract: Publication date: Available online 24 January 2019Source: Academic RadiologyAuthor(s): Allison Grayev
       
  • Comparison of Nongated Chest CT and Dedicated Calcium Scoring CT for
           Coronary Calcium Quantification Using a 256-Dector Row CT Scanner
    • Abstract: Publication date: Available online 23 January 2019Source: Academic RadiologyAuthor(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.
       
  • Comparison of Whole Heart Computed Tomography Scanners for Image Quality
           Lower Radiation Dosing in Coronary Computed Tomography Angiography: The
           CONVERGE Registry
    • Abstract: Publication date: Available online 23 January 2019Source: Academic RadiologyAuthor(s): Nirali Patel, Dong Li, Rine Nakanishi, Badiha Fatima, Daniele Andreini, Gianluca Pontone, Edoardo Conte, Rachael O'Rourke, Eranthi Jayawardena, Christian Hamilton-Craig, Manojna Nimmagadda, Matthew J. BudoffRationale and ObjectivesNovel technology in coronary computed tomographic angiography allows assessment of coronary artery disease with high image quality (IQ). There are currently two wide detector “whole heart” coverage scanners available, which avoid misregistration artifacts. However, there are no data directly comparing IQ between the two scanners. The aim of the current study is to investigate if IQ is different between the most current scanners of GE and Toshiba broad detector scanners.Materials and MethodsProspective, observational, multicenter international cohort study comparing 236 consecutive patients who underwent coronary computed tomographic angiography using whole-heart scanners; 126 patients on scanner S1 (Aquilion ONE, Toshiba), and 110 patients on scanner S2 (Revolution CT, GE Healthcare). Hounsfield units were measured using regions of interest in the descending aorta at 6 points (cranial slice, level of the visualized first, second, third, and fourth spines, and the caudal slice). We also compared the coverage length (z-axis) of the full width field of view between a single rotation of the two scanners.ResultsEvaluating mean CT attenuation values Hounsfield units through the scan range, are progressively reduced across the descending aorta in the S1 group, resulting in the larger difference of contrast brightness between the cranial and caudal slices compared to the S2 group (absolute difference: S2 13.0 ± 4.4 vs S1 141.9 ± 16.4, p < 0.0001; Percent difference: 19.3 ± 2.1 vs −3.4 ± 1.2,
       
  • 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: Available online 23 January 2019Source: Academic RadiologyAuthor(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.
       
  • A Victim of Our Own Success
    • Abstract: Publication date: Available online 22 January 2019Source: Academic RadiologyAuthor(s): N. Reed Dunnick
       
  • Raising the BAR: Challenges, Opportunities, and Hidden Gems in Radiology
           Education
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Nicole Restauri, Rustain MorganRationale and ObjectivesMedical student education in radiology has long been underrepresented in the curriculum despite the increased use of imaging in clinical medicine.Materials and MethodsThe Beginning to Advanced Radiology Lab, was created with the dedicated purpose of integrating digital technology and interactive teaching methods into the UME curriculum in radiology.ResultsResults: Development of a novel educational space at the University of Colorado allowed us to identify unforeseen challenges in medical student education while exploring new opportunitiesConclusionsConclusion: Curriculum revision in UME radiology education creates both challenges and opportunities and this paper explores these issues in the context of the current paradigm change in medical education.
       
  • Supporting Radiology Residents’ Professional Development Through a
           Competitive Intramural Grant
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Dexter Mendoza, Anna Holbrook, Frederic Bertino, Patricia Balthazar, Mary Newell, Carolyn C. MeltzerResearch and other scholarly activities are an important and required component of diagnostic radiology training. Several strategies, both at the departmental and the larger organizational levels, have been implemented to encourage radiology trainees to participate in these activities. In this article, we review and discuss our institution's 10-year experience in supporting the development and realization of scholarly projects through a competitive intramural grant for residents.
       
  • Uncited Research Articles in Popular United States General Radiology
           Journals
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Andrew B. Rosenkrantz, Ryan Chung, Richard DuszakRationale and ObjectivesThis study aimed to characterize articles in popular general radiology journals that go uncited for a decade after publication.MethodsUsing the Web of Science database, we identified annual citation counts for 13,459 articles published in Radiology, American Journal of Roentgenology, and Academic Radiology between 1997 and 2006. From this article cohort, we then identified all original research articles that accrued zero citations within a decade of publication. A concurrent equal-sized cohort of most cited articles was created. Numerous characteristics of the uncited and most cited articles were identified and compared.ResultsOnly 47 uncited articles went uncited for a decade after publication. When compared to the 47 most cited articles over that same window, the uncited articles were significantly (P 
       
  • CT Lymphangiography (CTL) in Primary Intestinal Lymphangiectasia (PIL): A
           Comparative Study with Intraoperative Enteroscopy (IOE)
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Jian Dong, Jianfeng Xin, Wenbin Shen, Tingguo Wen, Xiaobai Chen, Yuguang Sun, Rengui WangRationale and ObjectivesTo investigate the clinical feasibility of CT lymphangiography (CTL) in primary intestinal lymphangiectasia (PIL) by comparison with intraoperative enteroscopy (IOE) during exploratory laparotomy.Materials and MethodsEleven PIL patients (F/M, two/nine, age range 10–37 years) were recruited in this study, and they were performed IOE during exploratory laparotomy for suspected serious lymphatic-intestinal leakages. All the patients were performed CTL before surgery, and the imaging data were reviewed by two radiologists separately. CTL assessments included intestinal lesions, edematous lesions, intestinal and mesenteric lymphangiectasia, lymphaticabdominal leakages, lymph fluid reflux, lymphangioma and abnormal lymphatics in other area. The intestinal lymphangiectasia and lymphaticintestinal leakages were confirmed by histology and IOE.ResultsFor CTL, (1) nine intestinal wall thickening; (2) eight ascites, complicated with four pleural effusions, (3) eight intestinal and mesenteric lymphangiectasia, (4) six lymph fluid reflux (5) one lymphatic-abdominal leakage, (6) two lymphangioma. While for IOE, intestinal lymphangiectasia has been confirmed in all patients, including five segemental and six diffusive lesions in intestinal mucosa. Besides, one lymphatic-intestinal fistula, one lymphatic-abdominal leakage was confirmed. Compared to IOE and histology, the accuracy of CTL was 72.7% in detecting intestinal lymphangiectasia.ConclusionCompared to IOE, CTL demonstrates feasibility in detection of intestinal lymphangiectasia and other abnormalities in whole lymphatic circulation for PIL. Combination of CTL with IOE accommodates guidance for preoperative evaluation and therapeutic management for PIL.
       
  • 3D Printed Antibiotic and Chemotherapeutic Eluting Catheters for Potential
           Use in Interventional Radiology: In Vitro Proof of Concept Study
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Jeffery A. Weisman, David H. Ballard, Udayabhanu Jammalamadaka, Karthik Tappa, Jan Sumerel, Horacio B. D'Agostino, David K. Mills, Pamela K. WoodardRationale and ObjectivesAdditive manufacturing may be used as a form of personalized medicine in interventional radiology by allowing for the creation of customized bioactive constructs such as catheters that can act as a form of localized drug delivery. The purpose of the present in vitro study was to use three-dimensional (3D) printing to construct bioactive-laden bioabsorbable catheters impregnated with antibiotics and chemotherapeutics.Materials and MethodsPolylactic acid bioplastic pellets were coated with the powdered bioactive compounds gentamicin sulfate (GS) or methotrexate (MTX) to incorporate these drugs into the 3D printed constructs. The pellets were then extruded into drug-impregnated filament for fused deposition modeling 3D printing. Computer-aided design files were generated in the shapes of 14-F catheters. Scanning electron microscope imaging was used to visualize the presence of the additive powders on the surface of the printed constructs. Elution profiles were run on the antibiotic-laden catheter and MTX-laden catheters. Antibiotic-laden catheters were tested on bacterial broth and plate cultures.ResultsBoth GS and MTX catheter constructs had sustained drug release up to the 5-day limit of testing. The 3D printed GS-enhanced catheters inhibited all bacterial growth in broth cultures and had an average zone of inhibition of 858 ± 118 mm2 on bacterial plates, whereas control catheters had no effect.ConclusionThe 3D printing manufacturing method to create instruments in percutaneous procedures is feasible. Further in vivo studies will substantiate these findings.
       
  • Detection of Intra-Articular Screw Penetration of Proximal Humerus
           Fractures: Is Postoperative Computed Tomography the Necessary Imaging
           Modality'
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Xiaoyang Jia, Yanxi Chen, Minfei Qiang, Kun Zhang, Haobo Li, Yuchen Jiang, Yijie ZhangRationale and ObjectiveScrew penetration is the common complication of proximal humerus fractures treated with locking plates. This study compared postoperative plain radiography to computed tomography (CT) for their abilities in determining screw penetration, and was to evaluate whether advanced imaging modalities (two-dimensional [2D] CT; three-dimensional [3D] CT) could increase surgeons' level of confidence regarding their diagnoses.Materials and MethodsTwo observers reviewed radiological images of 134 patients who sustained proximal humerus fractures treated with locking plates. The observers were asked to answer two questions: (1) Is there screw penetrating into glenohumeral joint for this patient (Yes/No)' and (2) On a scale from 0 to 10, how confident are you about this diagnosis: (0–10) (0 = not at all confident; 10 = very confident)' Three evaluations were performed: (1) plain radiography alone, (2) radiography and 2D CT 4 weeks later, and (3) radiography in combination with 2D and 3D CT after that. This process was then repeated for intraobserver analysis.ResultsCT obtained almost perfect interobserver and intraobserver agreement (0.818–0.961), which was higher than radiography (0.377–0.655). For incidence of screw penetration, the significant difference was found between radiographs and CT images (P  .05). For confidence of diagnosis, the differences between imaging modalities were significant (all P 
       
  • Comparison of the Diagnostic Value of Monoexponential, Biexponential, and
           Stretched Exponential Diffusion-weighted MRI in Differentiating Tumor
           Stage and Histological Grade of Bladder Cancer
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Yanchun Wang, Daoyu Hu, Hao Yu, Yaqi Shen, Hao Tang, Ihab R. Kamel, Zhen LiRationale and ObjectivesWe aimed to determine the utility of various diffusion parameters obtained from monoexponential, biexponential, and stretched exponential diffusion-weighted imaging (DWI) models in differentiating tumor stage and grade of bladder cancer.Materials and MethodsForty-five patients with pathologically confirmed bladder cancer underwent multi-b-value DWI. An apparent diffusion coefficient (ADC) was calculated from DWI by using a monoexponential model. A true diffusion coefficient (D), perfusion-related pseudo-diffusion coefficient (D*), and perfusion fraction (f) were calculated from DWI by using a biexponential model. A water molecular diffusion heterogeneity index (α) and distributed diffusion coefficient (DDC) were calculated from DWI by using a stretched exponential model. All parameters were compared between different stages and grades by using the Mann-Whitney U test. Receiver operating characteristic and intrareader correlation coefficient analysis were used for statistical evaluations.ResultsADC, D, f, and DDC values were significantly higher in the non–muscle-invasive vs muscle-invasive bladder cancers (P = .000, .000, .002, and .000, respectively) and in low-grade vs high-grade ones (P = .000, .000, .018, and .000, respectively). D* value was significantly lower in the low-grade bladder cancers compared to high-grade ones (P = .012). The areas under the receiver operating characteristic curve of ADC, D, and DDC values were 0.945, 0.912, and 0.946 in staging bladder cancers; 0.866, 0.862, and 0.856 in grading bladder cancers, respectively.ConclusionBiexponential and stretched exponential DWI models may provide more parameters in staging and grading bladder cancers and show a slight difference between DDC and ADC values in staging bladder cancers. These two DWI models, as well as the monoexponential models, were very helpful in staging and grading bladder cancers.
       
  • Voxel-Wise Longitudinal Parametric Response Mapping Analysis of Chest
           Computed Tomography in Smokers
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Wassim W. Labaki, Tian Gu, Susan Murray, Charles R. Hatt, Craig J. Galbán, Brian D. Ross, Carlos H. Martinez, Jeffrey L. Curtis, Eric A. Hoffman, Esther Pompe, David A. Lynch, Ella A. Kazerooni, Fernando J. Martinez, MeiLan K. HanRationale and ObjectivesChronic obstructive pulmonary disease is a heterogeneous disease characterized by small airway abnormality and emphysema. We hypothesized that a voxel-wise computed tomography analytic approach would identify patterns of disease progression in smokers.Materials and MethodsWe analyzed 725 smokers in spirometric GOLD stages 0-4 with two chest CTs 5 years apart. Baseline inspiration, follow-up inspiration and follow-up expiration images were spatially registered to baseline expiration so that each voxel had correspondences across all time points and respiratory phases. Voxel-wise Parametric Response Mapping (PRM) was then generated for the baseline and follow-up scans. PRM classifies lung as normal, functional small airway disease (PRMfSAD), and emphysema (PRMEMPH).ResultsSubjects with low baseline PRMfSAD and PRMEMPH predominantly had an increase in PRMfSAD on follow-up; those with higher baseline PRMfSAD and PRMEMPH mostly had increases in PRMEMPH. For GOLD 0 participants (n = 419), mean 5-year increases in PRMfSAD and PRMEMPH were 0.3% for both; for GOLD 1–4 participants (n = 306), they were 0.6% and 1.6%, respectively. Eighty GOLD 0 subjects (19.1%) had overall radiologic progression (30.0% to PRMfSAD, 52.5% to PRMEMPH, and 17.5% to both); 153 GOLD 1–4 subjects (50.0%) experienced progression (17.6% to PRMfSAD, 48.4% to PRMEMPH, and 34.0% to both). In a multivariable model, both baseline PRMfSAD and PRMEMPH were associated with development of PRMEMPH on follow-up, although this relationship was diminished at higher levels of baseline PRMEMPH.ConclusionA voxel-wise longitudinal PRM analytic approach can identify patterns of disease progression in smokers with and without chronic obstructive pulmonary disease.
       
  • Additive Benefit of Radiomics Over Size Alone in the Distinction Between
           Benign Lesions and Luminal A Cancers on a Large Clinical Breast MRI
           Dataset
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Heather M. Whitney, Nathan S. Taylor, Karen Drukker, Alexandra V. Edwards, John Papaioannou, David Schacht, Maryellen L. GigerRationale and ObjectivesThe objective of this study was to demonstrate improvement in distinguishing between benign lesions and luminal A breast cancers in a large clinical breast magnetic resonance imaging database by using quantitative radiomics over maximum linear size alone.Materials and MethodsIn this retrospective study, 264 benign lesions and 390 luminal A breast cancers were automatically segmented from dynamic contrast-enhanced breast magnetic resonance images. Thirty-eight radiomic features were extracted. Tenfold cross validation was performed to assess the ability to distinguish between lesions and cancers using maximum linear size alone and lesion signatures obtained with stepwise feature selection and a linear discriminant analysis classifier including and excluding size features. Area under the receiver operating characteristic curve (AUC) was used as the figure of merit.ResultsFor maximum linear size alone, AUC and 95% confidence interval was 0.684 (0.642, 0.724) compared to 0.728 (0.687, 0.766) (P = 0.005) and 0.729 (0.689, 0.767) (P = 0.005) for lesion signature feature selection protocols including and excluding size features, respectively. The features of irregularity and entropy were chosen in all folds when size features were included and excluded. AUC for the radiomic signature using feature selection from all features was statistically equivalent to using feature selection from all features excluding size features, within an equivalence margin of 2%.ConclusionsInclusion of multiple radiomic features, automatically extracted from magnetic resonance images, in a lesion signature significantly improved the ability to distinguish between benign lesions and luminal A breast cancers, compared to using maximum linear size alone. The radiomic features of irregularity and entropy appear to play an important but not a solitary role within the context of feature selection and computer-aided diagnosis.
       
  • Transjugular Intrahepatic Portosystemic Shunt:The Impact of Portal Venous
           Pressure Declines on Shunt Patency and Clinical Efficacy
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Yue-Meng Wan, Yu-Hua Li, Zhi-Yuan Xu, Hua-Mei Wu, Xi-Nan Wu, Ying Xu, Tao GuoRationale and ObjectivesTransjugular intrahepatic portosystemic shunt (TIPS) placement using the same-diameter covered stents can lead to differed declines of portal venous pressure declines (PVDs). This study aimed to compare the long-term shunt patency and clinical efficacy of TIPS placement that caused low PVDs (≤9 mmHg) and high PVDs (>9 mmHg).Materials and MethodsA total of 129 patients treated by TIPS placement with 8 mm-diameter polytetrafluoroethylene covered stents were included and analyzed retrospectively. They were stratified into group A with low PVDs (n = 69) and group B with high PVDs (n = 60).ResultsThe 6-year actuarial probabilities of remaining free of shunt dysfunction (47.2% vs 64.6%; p = 0.007) and variceal rebleeding (48.3% vs 63.9%; p = 0.038) were significantly lower in group A than in group B. The 6-year actuarial probability of remaining free of hepatic encephalopathy was significantly higher in group A than in group B (44.5% vs 32.5%; p = 0.010), though the 6-year cumulative survival rate was similar in both groups (A vs B: 65.5% vs 56.0%; p = 0.240). The baseline portal vein thrombosis (hazard ratio [HR]: 6.045, 95% confidence interval [CI]: 2.762–13.233; p = 0.000) and stent type (HR: 4.447, 95%CI: 1.711–11.559, p = 0.002) were associated with shunt dysfunction, whereas only ascites was associated with mortality (HR: 1.373, 95%CI: 1.114–3.215; p = 0.024).ConclusionHigh PVDs (>9 mmHg) were associated with higher shunt patency, lower incidence of variceal rebleeding, but higher frequency of hepatic encephalopathy and similar survival rate than low PVDs (≤9 mmHg) after TIPS placement.
       
  • DCE-MRI in Human Gliomas: A Surrogate for Assessment of Invasive Hypoxia
           Marker HIF-1Α Based on MRI-Neuronavigation Stereotactic Biopsies
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Qian Xie, Juan Wu, Zunguo Du, Ningning Di, Ren Yan, Haopeng Pang, Teng Jin, Hua Zhang, Yue Wu, Yong Zhang, Zhenwei Yao, Xiaoyuan FengRationale and ObjectivesThe purpose of this study was to correlate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters with data from a specific marker of hypoxia, hypoxia-inducible factor 1α (HIF-1α), in human gliomas on a point-to-point basis by using coregistered magnetic resonance imaging and frameless stereotactic biopsies.Materials and MethodsThirty-four patients with treatment-naive gliomas underwent DCE, axial T1-weighted, T2-weighted, T2-weighted fluid acquisition of inversion recovery, and three-dimensional T1-weighted brain volume with gadolinium contrast enhancement sequences on a 3.0-T magnetic resonance scanner before stereotactic surgery. Quantitative perfusion indices such as endothelial transfer constant, fractional extravascular extracellular space volume, fractional plasma volume, and reflux rate were measured at corresponding stereotactic biopsy sites. Each sample was considered an independent measurement, and its histology grade was diagnosed. HIF-1α expression was quantified from the point-to-point biopsy tissues. Analyses of receiver operating characteristic curves were done for HIF-1α to discriminate different grades of glioma. To look for correlations between immunohistochemical parameters and DCE indices, Spearman's correlation coefficient was used.ResultsSeventy biopsy samples from 34 subjects were included in the analysis. Mean immunoreactivity scores of HIF-1α were 2.75 ± 1.11 for grade II (n = 24), 6.20 ± 2.33 for grade III (n = 20), and 10.46 ± 2.42 for grade IV (n = 26). HIF-1α showed very good-to-excellent accuracy in discriminating grade II from III, III from IV, and II from IV (area under the curve = 0.838, 0.862, and 0.994, respectively). Endothelial transfer constant and fractional extravascular extracellular space volume showed a significantly positive correlation with HIF-1α expression (r = 0.686, P 
       
  • Functional Pulmonary Magnetic Resonance Imaging for Detection of Ischemic
           Injury in a Porcine Ex-Vivo Lung Perfusion System Prior to Transplantation
           
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Julius Renne, Marcel Gutberlet, Andreas Voskrebenzev, Agilo Kern, Till Kaireit, Jan B Hinrichs, Peter Braubach, Christine S Falk, Klaus Höffler, Gregor Warnecke, Patrick Zardo, Axel Haverich, Frank Wacker, Jens Vogel-Claussen, Norman ZinneRationale and ObjectivesTo evaluate the feasibility of multiparametric magnetic resonance imaging (MRI) of the lungs to detect impaired organ function in a porcine model of ischemic injury within an ex-vivo lung perfusion system (EVLP) prior to transplantation.Materials and MethodsTwelve pigs were anesthetized, and left lungs were clamped to induce warm ischemia for 3 hours. Right lungs remained perfused as controls. Lungs were removed and installed in an EVLP for 12 hours. Lungs in the EVLP were imaged repeatedly using computed tomography, proton MRI (1H-MRI) and fluorine MRI (19F-MRI). Dynamic contrast-enhanced derived parenchymal blood volume, oxygen washout times, and 19F washout times were calculated. PaO2 was measured for ischemic and normal lungs, wet/dry ratio was determined, histologic samples were assessed, and cytokines in the lung tissue were analyzed. Statistical analysis was performed using nonparametric testing.ResultsEleven pigs were included in the final analysis. Ischemic lungs showed significantly higher wet/dry ratios (p = 0.024), as well as IL-8 tissue levels (p = 0.0098). Histologic assessment as well as morphologic scoring of computed tomography and 1H-MRI did not reveal significant differences between ischemic and control lungs. 19F washout (p = 0.966) and parenchymal blood flow (p = 0.32) were not significantly different. Oxygen washout was significantly prolonged in ischemic lungs compared to normal control lungs at the beginning (p = 0.018) and further prolonged at the end of the EVLP run (p = 0.005).ConclusionMultiparametric pulmonary MRI is feasible in lung allografts within an EVLP system. Oxygen-enhanced imaging seems to be a promising marker for ischemic injury, enabling detection of affected lung segments prior to transplantation.
       
  • Monitoring and Follow-Up of High Radiation Dose Cases in Interventional
           Radiology
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Brandon C. Perry, Christopher R. Ingraham, Brent K. Stewart, Karim Valji, Kalpana M. KanalRationale and ObjectivesTo assess the implementation of radiation dose monitoring software, create a process for clinical follow-up and documentation of high-dose cases, and quantify the number of patient reported radiation-induced tissue reactions in fluoroscopically guided interventional radiology (IR) and neuro-interventional radiology (NIR) procedures.Materials and MethodsWeb-based radiation dose monitoring software was installed at our institution and a process to flag all procedures with reference point air kerma (Ka,r)> 5000 mGy was implemented. The entrance skin dose was estimated and formal reports generated, allowing for physician-initiated clinical follow-up. To evaluate our process, we reviewed all IR and NIR procedures performed at our hospital over a 1-year period. For all procedures with Ka,r> 5000 mGy, retrospective medical chart review was performed to evaluate for patient reported tissue reactions.ResultsThree thousand five hundred eighty-two procedures were performed over the 1-year period. The software successfully transferred dose data on 3363 (93.9%) procedures. One thousand three hundred ninety-three (368 IR and 1025 NIR) procedures were further analyzed after excluding 2189 IR procedures with Ka,r < 2000 mGy. Ten of 368 (2.7%) IR and 52 of 1025 (5.1%) NIR procedures exceeded estimated skin doses of 5000 mGy. All 10 IR cases were abdominal/pelvic trauma angiograms with/without embolization; there were no reported tissue reactions. Of 52 NIR cases, 49 were interventions and 3 were diagnostic angiograms. Five of 49 (10.2%) NIR patients reported skin/hair injuries, all of which were temporary.ConclusionSoftware monitoring and documentation of radiation dose in interventional procedures can be successfully implemented. Radiation-induced tissue reactions are relatively uncommon.
       
  • Association Between BRAFV600E Mutation and the American College of
           Radiology Thyroid Imaging, Reporting and Data System in Solitary Papillary
           Thyroid Carcinoma
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Ronger Shangguan, Yuan-Ping Hu, Jun Huang, Shao-Jun Yang, Ling Ye, Ri-Xu Lin, Jian Zhu, Tong-Long Zhang, Li Ying, Peng LiRationale and Objectives: The purpose of this study was to evaluate the associations between BRAFV600E mutation, the American College of Radiology (ACR) thyroid imaging, reporting and data system (TI-RADS) on ultrasound and clinicopathological characteristics in patients with a solitary papillary thyroid carcinoma (PTC).Materials and Methods: This retrospective study included 397 patients with a solitary PTC, proved pathologically. BRAFV600E mutation status was detected in postoperative samples by real-time fluorescent polymerase chain reaction. Associations of BRAFV600E mutation with the ACR TI-RADS and clinicopathological characteristics were analyzed.Results: In this study, the incidence of BRAFV600E mutation was 81.4% (323/397) in patients with a solitary PTC. Univariate analyses showed that BRAFV600E mutation was significantly associated with margin, higher ACR TI-RADS point scores, and Hashimoto's thyroiditis. In multivariate analyses, lobulated or irregular margin was independently associated with BRAFV600E mutation in total solitary PTC. Furthermore, both in total solitary PTC and papillary thyroid microcarcinoma, BRAFV600E mutation was associated with ACR TI-RADS point scores, which was positively correlated with the risk of BRAFV600E mutation. There was no significant relationship between BRAFV600E mutation and ACR TI-RADS point scores in PTC>10 mm. In addition, Hashimoto's thyroiditis had a significant negative association with BRAFV600E mutation.Conclusion: A lobulated or irregular margin of the thyroid nodule is independently associated with BRAFV600E mutation in patients with PTC. In addition, higher ACR TI-RADS point scores is an independent risk factor for BRAFV600E mutation, and ACR TI-RADS point scores is positively associated with the risk of BRAFV600E mutation in solitary PTC, especially in papillary thyroid microcarcinoma. Our findings may be helpful for preoperative identification and medical management of PTC patients with BRAFV600E mutation.
       
  • Feasibility of Intravoxel Incoherent Motion for Differentiating Benign and
           Malignant Thyroid Nodules
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Hui Tan, Jun Chen, Yi ling Zhao, Jin huan Liu, Liang Zhang, Chang sheng Liu, Dongjie HuangRationale and ObjectivesThis study aimed to preliminarily investigate the feasibility of intravoxel incoherent motion (IVIM) theory in the differential diagnosis of benign and malignant thyroid nodules.Materials and MethodsForty-five patients with 56 confirmed thyroid nodules underwent preoperative routine magnetic resonance imaging and IVIM diffusion-weighted imaging. The histopathologic diagnosis was confirmed by surgery. Apparent diffusion coefficient (ADC), perfusion fraction f, diffusivity D, and pseudo-diffusivity D* were quantified. Independent samples t test of IVIM-derived metrics were conducted between benign and malignant nodules. Receiver-operating characteristic analyses were performed to determine the optimal thresholds as well as the sensitivity and specificity for differentiating.ResultsSignificant intergroup difference was observed in ADC, D, D*, and f (p < 0.001). Malignant tumors featured significantly lower ADC, D and D* values and a higher f value than that of benign nodules. The ADC, D, and D* could distinguish the benign from malignant thyroid nodules, and parameter f differentiate the malignant tumors from benign nodules. The values of the area under the curve for parameter ADC, D, and D* were 0.784 (p = 0.001), 0.795 (p = 0.001), and 0.850 (p < 0.001), separately, of which the area under the curve of f value was the maximum for identifying the malignant from benign nodules, which was 0.841 (p < 0.001).ConclusionThis study suggested that ADC and IVIM-derived metrics, including D, D*, and f, could potentially serve as noninvasive predictors for the preoperative differentiating of thyroid nodules, and f value performed best in identifying the malignant from benign nodules among these parameters.
       
  • Establishing a Surgical Preliminary Year in the IR Residency: Keys to
           Success
    • Abstract: Publication date: February 2019Source: Academic Radiology, Volume 26, Issue 2Author(s): Minhaj S. Khaja, William M. Sherk, Paul G. Gauger, David T. Hughes, N. Reed Dunnick, Janet E. Bailey, Wael E. SaadThe training paradigm of the interventional radiologist has quickly evolved with the approval of the integrated interventional radiology (IR) residency by the American Board of Medical Specialties and the Accreditation Council of Graduate Medical Education. Prior to appointment in an integrated IR program, a resident must complete a preliminary clinical year, which may be surgical, medical, or transitional. The unique procedural- and clinical-based skillset required of the IR resident is best aligned with a surgical preliminary year. The following is a review of the steps to successful creation of a surgical preliminary year based on a single institution's experience.
       
  • Changes in the Utilization of the BI-RADS Category 3 Assessment in
           Recalled Patients Before and After the Implementation of Screening Digital
           Breast Tomosynthesis
    • Abstract: Publication date: Available online 19 January 2019Source: Academic RadiologyAuthor(s): Tricia Stepanek, Niki Constantinou, Holly Marshall, Ramya Pham, Cheryl Thompson, Christina Dubchuk, Donna PlechaRationale and ObjectivesThe purpose of this study was to compare the utilization of the Breast Imaging Reporting and Data System (BI-RADS) category 3 assessment in patients recalled from screening before and after the implementation of digital breast tomosynthesis (DBT).Materials and MethodsThis was a retrospective review of 11,478 digital mammography (DM) screening exams and 9350 DM+DBT screening exams. Lesions assigned a BI-RADS category 3 at diagnostic exam were classified as architectural distortions, asymmetries, calcifications, masses, and “other” and followed for a minimum of 2 years.ResultsThe addition of DBT to screening DM resulted in a 30.4% relative reduction (10.3 women per 1000) in the utilization of BI-RADS category 3 compared to screening DM alone (3.4% for DM versus 2.4% for DM+DBT; p < 0.0001). There was a statistically significant change in the distribution of category 3 findings with DM+DBT characterized by an increase in calcifications and architectural distortions and a decrease in asymmetries. There was no change in category 3 assessment for masses. Although both cohorts had delayed cancer detection rates that exceeded the recommended 2% benchmark (2.3% for DM and 3.6% for DM+DBT), when limited to invasive malignancies, the delayed cancer detection rates were below the 2% benchmark (1.5% for DM and 0.9% for DM+DBT). Screening DM+DBT resulted in a 9.2% relative reduction in recall rate compared to DM (13.0% for DM versus 11.8% for DM+ DBT, p = 0.012).ConclusionImplementation of DBT in the screening population decreased the overall number of patients assigned to short-term follow-up by 10.3 per 1000 women while maintaining comparable rates of delayed cancer detection.
       
  • Institutional Implementation of a Structured Reporting System: Our
           Experience with the Brain Tumor Reporting and Data System
    • Abstract: Publication date: Available online 18 January 2019Source: Academic RadiologyAuthor(s): Ashwani Gore, Michael J. Hoch, Hui-Kuo G. Shu, Jeffrey J. Olson, Alfredo D. Voloschin, Brent D. WeinbergRationale and ObjectivesAnalyze the impact of implementing a structured reporting system for primary brain tumors, the Brain Tumor Reporting and Data System, on attitudes toward radiology reports at a single institution.Materials and MethodsFollowing Institutional Review Board approval, an initial 22 question, 5 point (1—worst to 5—best), survey was sent to faculty members, house staff members, and nonphysician providers at our institution who participate in the direct care of brain tumor patients. Results were used to develop a structured reporting strategy for brain tumors which was implemented across an entire neuroradiology section in a staged approach. Nine months following structured reporting implementation, a follow-up 27 question survey was sent to the same group of providers. Keyword search of radiology reports was used to assess usage of Brain Tumor Reporting and Data System over time.ResultsFifty-three brain tumor care providers responded to the initial survey and 38 to the follow-up survey. After implementing BT-RADS, respondents reported improved attitudes across multiple areas including: report consistency (4.3 vs. 3.4; p < 0.001), report ambiguity (4.2 vs. 3.2, p < 0.001), radiologist/physician communication (4.5 vs. 3.8; p < 0.001), facilitation of patient management (4.2 vs. 3.6; p = 0.003), and confidence in reports (4.3 vs. 3.5; p < 0.001). Providers were more satisfied with the BT-RADS structured reporting system (4.3 vs. 3.7; p = 0.04). Use of the reporting template progressively increased with 81% of brain tumor reports dictated using the new template by 9 months.ConclusionImplementing a structured template for brain tumor imaging improves perception of radiology reports among radiologists and referring providers involved in the care of brain tumor patients.
       
  • Does the Apparent Diffusion Coefficient Value Predict Permanent Cerebral
           Ischemia/Reperfusion Injury in Rats'
    • Abstract: Publication date: Available online 17 January 2019Source: Academic RadiologyAuthor(s): Jae-Im Kwon, Chul-Woong Woo, Kyung-Won Kim, Yoonseok Choi, Sang-Tae Kim, Yun Jae Kim, Jeeheon Kang, Do-Wan Lee, Eunyoung Tak, Jeong-Kon Kim, Seung-Chae Jung, Tae-Hyung Kim, Dong-Cheol WooRationale and ObjectivesVariation in tissue damage after cerebral ischemia/reperfusion (I/R) can cause uncertainty in stroke-related studies, which can be reduced if the damage can be predicted early after ischemia by measuring the apparent diffusion coefficient (ADC). We investigated whether ADC measurement in the acute phase can predict permanent cerebral I/R injury.Materials and MethodsThe middle cerebral artery occlusion model was established using the intraluminal suture method to induce 60 minutes of ischemia followed by reperfusion in rats. T2-weighted images and diffusion-weighted images were obtained at 30 minutes and 24 hours after ischemia. Neuronal cell survival was assessed by neuronal nuclei (NeuN) immunofluorescence staining. The correlation between relative ADC (rADC) values at 30 minutes and I/R injury at 24 hours after ischemia was analyzed. Magnetic resonance imaging results were confirmed by histologic analysis.ResultsThe correlation between rADC values at 30 minutes and 24 hours was strong in the ischemic core and peri-infarct region but moderate in the anterior choroidal and hypothalamic region. Histologic analysis revealed that the correlation between rADC values at 30 minutes and the number of NeuN-positive cells at 24 hours was strong in the ischemic core and peri-infarct region but moderate in the anterior choroidal and hypothalamic region. Furthermore, there was a strong positive correlation between the sum of rADC values of three regions at 30 minutes and the infarct volume at 24 hours.ConclusionADC measurement in the acute phase can predict permanent cerebral I/R injury and provide important information for the evaluation of ischemic stroke.
       
  • Machine Learning to Differentiate T2-Weighted Hyperintense Uterine
           Leiomyomas from Uterine Sarcomas by Utilizing Multiparametric Magnetic
           Resonance Quantitative Imaging Features
    • Abstract: Publication date: Available online 17 January 2019Source: Academic RadiologyAuthor(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.
       
  • The Importance of Learning to Listen
    • Abstract: Publication date: Available online 17 January 2019Source: Academic RadiologyAuthor(s): Richard B. Gunderman
       
  • The Application of a New Model-Based Iterative Reconstruction in Low-Dose
           Upper Abdominal CT
    • Abstract: Publication date: Available online 17 January 2019Source: Academic RadiologyAuthor(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.
       
  • Initial Clinical Experience with Stationary Digital Breast Tomosynthesis
    • Abstract: Publication date: Available online 17 January 2019Source: Academic RadiologyAuthor(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.
       
  • Development and Validation of a MRI-Based Radiomics Prognostic Classifier
           in Patients with Primary Glioblastoma Multiforme
    • Abstract: Publication date: Available online 17 January 2019Source: Academic RadiologyAuthor(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.
       
  • Differentiation Between Multiple System Atrophy and Other Spinocerebellar
           Degenerations Using Diffusion Kurtosis Imaging
    • Abstract: Publication date: Available online 16 January 2019Source: Academic RadiologyAuthor(s): Kenji Ito, Chigumi Ohtsuka, Kunihiro Yoshioka, Tetsuya Maeda, Suguru Yokosawa, Futoshi Mori, Tsuyoshi Matsuda, Yasuo Terayama, Makoto SasakiRationale and ObjectiveDifferentiation between multiple system atrophy (MSA) and other spinocerebellar degenerations showing cerebellar ataxia is often difficult. Hence, we investigated whether magnetic resonance diffusion kurtosis imaging (DKI) could detect pathological changes that occur in these patients and be used for differential diagnosis.MethodsThirty-six subjects (12 patients with MSA accompanied by predominant cerebellar ataxia [MSA-C], 10 patients with spinocerebellar ataxias [SCAs] or sporadic adult-onset ataxia of unknown etiology [SAOA], and 14 healthy controls) were examined using 1.5- or 3-T magnetic resonance scanners. From the DKI data, the mean kurtosis, fractional anisotropy, and mean diffusivity values of the pontine crossing tract (PCT), middle cerebellar peduncle, and cerebellum were automatically measured, and the ratios against the values of the corpus callosum were calculated.ResultsWe found significant decreases in mean kurtosis and fractional anisotropy ratios in the PCT and middle cerebellar peduncle, and a significant increase in the mean diffusivity ratio in the PCT in the MSA-C group, as compared with the SCA/SAOA and control groups (p < 0.027–0.001). Among these metrics, there were no significant differences in the diagnostic performance. By contrast, the ratios in the cerebellum showed no significant differences between the MSA-C and SCA/SAOA groups but were significantly altered when compared with the controls (p < 0.001).ConclusionQuantitative DKI analyses can be used to differentiate between patients with MSA-C and those with SCA/SAOA.
       
  • “Structure-Function Imaging of Lung Disease Using Ultrashort Echo
           Time MRI”
    • Abstract: Publication date: Available online 16 January 2019Source: Academic RadiologyAuthor(s): Luis Torres, Jeff Kammerman, Andrew D. Hahn, Wei Zha, Scott K. Nagle, Kevin Johnson, Nathan Sandbo, Keith Meyer, Mark Schiebler, Sean B. FainRationale and Objectives: The purpose of this review is to acquaint the reader with recent advances in ultrashort echo time (UTE) magnetic resonance imaging (MRI) of the lung and its implications for pulmonary MRI when used in conjunction with functional MRI technique. Materials and Methods: We provide an overview of recent technical advances of UTE and explore the advantages of combined structure-function pulmonary imaging in the context of restrictive and obstructive pulmonary diseases such as idiopathic pulmonary fibrosis (IPF) and cystic fibrosis (CF). Results:UTE MRI clearly shows the lung parenchymal changes due to IPF and CF. The use of UTE MRI, in conjunction with established functional lung MRI in chronic lung diseases, will serve to mitigate the need for computed tomography in children.Conclusion:Current limitations of UTE MRI include long scan times, poor delineation of thin-walled structures (e.g. cysts and reticulation) due to limited spatial resolution, low signal to noise ratio, and imperfect motion compensation. Despite these limitations, UTE MRI can now be considered as an alternative to multidetector computed tomography for the longitudinal follow-up of the morphological changes from lung diseases in neonates, children, and young adults, particularly as a complement to the unique functional capabilities of MRI.
       
  • 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: Available online 15 January 2019Source: Academic RadiologyAuthor(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.
       
  • Application of Adaptive Statistical Iterative Reconstruction-V With
           Combination of 80 kV for Reducing Radiation Dose and Improving Image
           Quality in Renal Computed Tomography Angiography for Slim Patients
    • Abstract: Publication date: Available online 15 January 2019Source: Academic RadiologyAuthor(s): Zhanli Ren, Xirong Zhang, Zhijun Hu, Dou Li, Zhentang Liu, Donghong Wei, Yongjun Jia, Nan Yu, Yong Yu, Yuxin Lei, Xiaoxia Chen, Changyi Guo, Zhanliang Ren, Taiping HeObjectivesTo explore the application of adaptive statistical iterative reconstruction-V (ASIR-V) with combination of 80 kV for reducing radiation dose and improving image quality in renal computed tomography angiography (CTA) for slim patients compared with traditional filtered back projection (FBP) reconstruction using 120 kV.MethodsEighty patients for renal CTA were prospectively enrolled and randomly divided into group A and group B. Group A used 120 kV and 600 mgI/kg contrast agent and FBP reconstruction, while group B used 80 kV and 350 mgI/kg contrast agent and both FBP and ASIR-V reconstruction from 10%ASIR-V to 100%ASIR-V with 10%ASIR-V interval. The CT values and SD values of the right renal artery and left renal artery were measured to calculate the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The image quality was subjectively scored by two experienced radiologists blindly using a five-point criterion. The contrast agent, volumetric CT dose index (CTDIvol), and dose length product in both groups were recorded and the effective radiation dose was calculated.ResultsThere were no significant difference in patient characteristics between two groups (p> 0.05). The CTDIvol, dose length product and effective radiation dose in group B were 59.0%, 65.0%, and 65.1% lower than those in group A, respectively (all p < 0.05), and the contrast agent in group B was 42.2% lower than that in group A (p < 0.05). In group B, with the increase of ASIR-V percentage, CT values showed no significant difference, SD values decreased gradually, SNR values and CNR values increased gradually. The CT values showed no statistically significant difference (p> 0.05) between two groups with different reconstructions. The SD values with 40%ASIR-V to 100%ASIR-V reconstruction in group B was significantly lower(p < 0.5), while the SNR values with 50% ASIR-V to 100% ASIR-V reconstruction and CNR values with 70%ASIR-V to 100%ASIR-V were significantly higher than those of group A with FBP reconstruction (p < 0.5). Two radiologists had excellent consistency in subjective scores of image quality for renal CTA (kappa>0.75, p < 0.05). The subjective scores with 60% ASIR-V to 90% ASIR-V in group B were significantly higher than those of FBP in group A (p < 0.5), of which 70%ASIR-V reconstruction obtained the highest subjective score for renal CTA.ConclusionASIR-V with combination of 80 kV can significantly reduce effective radiation dose (about 65.1%) and contrast agent (about 42.2%) and improve image quality in renal CTA for slim patients compared with traditional FBP reconstruction using 120 kV, and the 70% ASIR-V was the best reconstruction algorithm in 80 kV renal CTA.Advances in KnowledgeUsing 80 kV with combination of ASIR-V can significantly reduce radiation dose and contrast agent dose as well as improve image quality in renal CTA for thin patients when compared with FBP using 120 kV.
       
  • “Code-Stroke” CT Perfusion; Challenges and Pitfalls
    • Abstract: Publication date: Available online 14 January 2019Source: Academic RadiologyAuthor(s): Houman Sotoudeh, Asim K. Bag, Michael David BrooksRationale and ObjectivesRegarding the most recent ischemic stroke treatment guideline, perfusion imaging has been recommended up to 24 hours after initial symptoms of brain infarction. Patients with a significant amount of salvageable peri-infarct ischemia and no contraindications benefit from delayed thrombolysis and intra-arterial thrombectomy. This approach causes increasingly more CT perfusion to be done in the subacute phase of ischemic stroke. CT perfusion findings in this “subacute phase” are slightly different from “hyper-acute” ischemic stroke. The interpreting radiologist must be confident in reporting the CT perfusion study in an urgent setting since these studies are under the umbrella of “code-stroke” and should be read in minutes. In addition, results of the CT perfusion have a critical effect on the patient's outcome and misinterpretation can be fatal in that underestimation of the salvageable ischemia excludes the patient from potential effective treatment. Underestimation of infarct volume may cause unnecessary thrombolysis/thrombectomy and potentially fatal intracranial hemorrhage.Materials and MethodsIn this review, we are trying to explain the basic concept of “code-stroke” CT perfusion, typical findings, and pitfalls in a practical way.
       
  • Foreword: Recent Developments on Imaging Pulmonary System
    • Abstract: Publication date: Available online 14 January 2019Source: Academic RadiologyAuthor(s): Rahim R. Rizi
       
  • Detection of Extraprostatic Extension of Cancer on Biparametric MRI
           Combining Texture Analysis and Machine Learning: Preliminary Results
    • Abstract: Publication date: Available online 14 January 2019Source: Academic RadiologyAuthor(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.
       
  • Multibreath Hyperpolarized 3He Imaging Scheme to Measure Alveolar Oxygen
           Tension and Apparent Diffusion Coefficient
    • Abstract: Publication date: Available online 8 January 2019Source: Academic RadiologyAuthor(s): Tahmina Achekzai, Hooman Hamedani, Stephen J. Kadlecek, Kai Ruppert, Yi Xin, Ryan J. Baron, Ian F. Duncan, Federico Sertic, Sarmad Siddiqui, Faraz Amzajerdian, Mehrdad Pourfathi, Luis A. Loza, Maurizio Cereda, Rahim R. RiziRationale and ObjectivesIn this study, we compared a newly developed multibreath simultaneous alveolar oxygen tension and apparent diffusion coefficient (PAO2-ADC) imaging sequence to a single-breath acquisition, with the aim of mitigating the compromising effects of intervoxel flow and slow-filling regions on single-breath measurements, especially in chronic obstructive pulmonary disease (COPD) subjects.Materials and MethodsBoth single-breath and multibreath simultaneous PAO2-ADC imaging schemes were performed on a total of 10 human subjects (five asymptomatic smokers and five COPD subjects). Estimated PAO2 and ADC values derived from the different sequences were compared both globally and regionally. The distribution of voxels with nonphysiological values was also compared between the two schemes.ResultsThe multibreath protocol decreased the ventilation defect volumes by an average of 12.9 ± 6.6%. The multibreath sequence generated nonphysiological PAO2 values in 11.0 ± 8.5% fewer voxels than the single-breath sequence. Single-breath PAO2 maps also showed more regions with gas-flow artifacts and general signal heterogeneity. On average, the standard deviation of the PAO2 distribution was 16.5 ± 7.0% lower using multibreath PAO2-ADC imaging, suggesting a more homogeneous gas distribution. Both mean and standard deviation of the ADC increased significantly from single- to multibreath imaging (p = 0.048 and p = 0.070, respectively), suggesting more emphysematous regions in the slow-filling lung.ConclusionMultibreath PAO2-ADC imaging provides superior accuracy and efficiency compared to previous imaging protocols. PAO2 and ADC maps generated by multibreath imaging allowed for the qualification of various regions as emphysematous or obstructed, which single-breath PAO2 maps can only identify as defects. The simultaneous PAO2 and ADC measurements generated by the presented multibreath method were also more physiologically realistic, and allowed for more detailed analysis of the slow-filling regions characteristic of COPD subjects.
       
  • To Batch, or Not to Batch, That is the Question: Screening Tomosynthesis
           Interpretation Methods
    • Abstract: Publication date: Available online 31 December 2018Source: Academic RadiologyAuthor(s): Sarah M. Friedewald
       
  • Imaging Characterization of Thyroid Nodules
    • Abstract: Publication date: Available online 6 December 2018Source: Academic RadiologyAuthor(s): Chaitanya R. Divgi
       
  • Curating the PGY1 Year for Interventional Radiology Residency
    • Abstract: Publication date: Available online 6 December 2018Source: Academic RadiologyAuthor(s): M. Victoria Marx
       
  • Constricting the Radiologic Lexicon: An Orwellian Errand'
    • Abstract: Publication date: Available online 3 December 2018Source: Academic RadiologyAuthor(s): Benjamin R. Gray, Richard B. Gunderman
       
 
 
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