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Publisher: Elsevier   (Total: 3162 journals)

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Showing 1 - 200 of 3162 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: 33, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 23, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 95, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 25, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 36, 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: 413, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 27, 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: 251, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 12, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1, SJR: 1.793, CiteScore: 6)
Acta Poética     Open Access   (Followers: 4, SJR: 0.101, CiteScore: 0)
Acta Psychologica     Hybrid Journal   (Followers: 27, 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: 6)
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: 16, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 8, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 9, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 151, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, 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: 12, 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: 23, 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: 32, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 8, 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: 3)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 27, 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: 29, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19, 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: 5)
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: 28, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 44, 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: 58, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Genetics     Full-text available via subscription   (Followers: 16, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 8, 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: 21, 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: 22)
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: 8, 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: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 17, 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: 6, 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: 22)
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: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 1)
Advances in Organ Biology     Full-text available via subscription   (Followers: 1)
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: 24, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 11)
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: 9)
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: 18)
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: 62)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (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: 397, 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: 10, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 33, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 17)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 46, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 342, 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: 450, 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: 3)
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: 11, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 9)
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: 11, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 9, 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: 50, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 54, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 45, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 10)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, 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: 34, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 46)
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: 211, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 63, 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: 27, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 28, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 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: 62, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 17, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription  
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: 177, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 11, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 11)
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: 194, 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: 23  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1076-6332
Published by Elsevier Homepage  [3162 journals]
  • Age-Related Declines in Occipital GABA are Associated with Reduced Fluid
           Processing Ability
    • Abstract: Publication date: Available online 14 October 2018Source: Academic RadiologyAuthor(s): Molly Simmonite, Joshua Carp, Bradley R. Foerster, Lynn Ossher, Myria Petrou, Daniel H. Weissman, Thad A. PolkRationale and ObjectivesHealthy aging is associated with pervasive declines in cognitive, motor, and sensory functioning. There are, however, substantial individual differences in behavioral performance among older adults. Several lines of animal research link age-related reductions of gamma-aminobutyric acid (GABA), the brain's primary inhibitory neurotransmitter, to age-related cognitive, motor, and sensory decline. Our study used proton magnetic resonance spectroscopy (MRS) at 3T to explore whether occipital GABA declines with age in humans and whether individual differences in occipital GABA are linked to individual differences in fluid processing ability.Materials and MethodsWe used a MEGA-PRESS sequence that combines frequency spectral editing with a point-resolved spectroscopy sequence to quantify GABA. Spectra were obtained from a 30 × 30 × 25mm voxel placed in the occipital cortex of 20 young adults (mean age 20.7 years) and 18 older adults (mean age 76.5 years). Participants also performed 11 fluid processing tasks outside the scanner, the results of which were z-scored and averaged to calculate a summary measure of fluid processing ability. Regression analysis was employed to determine the relationship between GABA concentrations in the occipital cortex and a summary measure of fluid processing ability.ResultsOccipital GABA was significantly lower in older participants compared to the younger participants. We also observed a significant positive relationship between occipital GABA and fluid processing ability. In fact, higher GABA was associated with better task performance in 10 of the 11 tasks.ConclusionThese findings suggest that GABA levels decline with age in humans and are associated with declines in fluid processing ability.
       
  • The Diffusion Tensor Imaging Properties of the Normal Testicles at 3 Tesla
           Magnetic Resonance Imaging
    • Abstract: Publication date: Available online 13 October 2018Source: Academic RadiologyAuthor(s): Noam Nissan, Debbie Anaby, Ido Tavor, Yeruham Kleinbaum, Zohar Dotan, Eli Konen, Orith PortnoyRationale and ObjectivesThe testicles are structured in a well-defined microtubular network formation, which is expected to be reflected in high anisotropic diffusivity. However, preliminary studies reported on low values of fractional-anisotropy (FA) in the normal testicles. Our aim was to design and apply a diffusion-tensor imaging (DTI) protocol in order to elucidate the diffusivity properties of the testicles and their determining factors.Materials and Methods16 healthy volunteers were prospectively scanned at 3T. The protocol included T2-weighted and DTI sequences, the latter using 24 directional diffusion gradients and 3 b-values (0, 100, and 700 s/mm2) that were separated for analysis based on the reference b-value of 0 or 100 s/mm2. Image processing of the two DTI datasets yielded the diffusion vector maps and parametric maps of their corresponding principal diffusion coefficients λ1, λ2, λ3, mean diffusivity and FA.ResultsThe results demonstrated the feasibility of DTI to provide parametric maps of the testicles. The diffusion tensor parameters obtained using the pair of 0 and 700 s/mm2 b-values, exhibited relatively low diffusivity, with mean λ1 values of 1.36 ± 0.21 × 10−3 mm2/s and low anisotropy, with mean FA values of 0.13 ± 0.05. Analysis of DTI using the 100 and 700 s/mm2 b-values yielded a slight decrease in the diffusivity of 4%–5%, whereas FA remained similar.ConclusionThe diffusivity of the normal testicles is relatively slow, closed-to isotropic and hardly affected by the low b-values regime exclusion. Thus, DTI parameters of the normal testicles are neither dictated by the underlying architectural anisotropy nor microperfusion effects.
       
  • Radiologic and Pathologic Features Associated With Upgrade of Atypical
           Ductal Hyperplasia at Surgical Excision
    • Abstract: Publication date: Available online 12 October 2018Source: Academic RadiologyAuthor(s): Kristin E. Williams, Amanda Amin, Jacqueline Hill, Carissa Walter, Marc Inciardi, Jason Gatewood, Mark Redick, Jo Wick, Suzanne Hunt, Onalisa WinbladRationale and ObjectivesTo evaluate radiologic and pathologic features associated with upgrade of atypical ductal hyperplasia (ADH) to ductal carcinoma in situ or invasive breast cancer at surgical excision, in order to identify patients who may consider alternatives to excision.Materials and MethodsThis retrospective analysis examined patients who underwent surgical excision of biopsy-proven ADH at our institution. Imaging and pathology from biopsy were reviewed to determine radiologic (lesion size, radiologic abnormality, biopsy type, needle gauge, number of cores, percent of lesion removed) and pathologic features (histologic calcifications, presence of necrosis, micropapillary features, extent of ADH) associated with ADH upgrade.ResultsOne hundred twenty four cases of percutaneous biopsy-proven ADH with subsequent excision were included. The overall upgrade rate was 17.7% (n = 22), with 17 cases to ductal carcinoma in situ and five to invasive cancer. Radiologic features associated with a lower upgrade rate were smaller lesion size (p = 0.032) and larger percent of lesion removed at biopsy (p = 0.047). Larger needle gauge at biopsy (p = 0.070), absence of necrosis (p = 0.051) and focal ADH (
       
  • Utility of 13N-Ammonia PET/CT to Detect Pituitary Tissue in Patients with
           Pituitary Adenomas
    • Abstract: Publication date: Available online 12 October 2018Source: Academic RadiologyAuthor(s): Zongming Wang, Zhigang Mao, Xiangsong Zhang, Dongsheng He, Xin Wang, Qiu Du, Zheng Xiao, Diming Zhu, Yonghong Zhu, Haijun WangRationale and ObjectivesIt is clinically essential, but sometimes challenging, to distinguish pituitary tissue from pituitary adenomas (PAs). It is helpful to avoid damage of pituitary tissue during management. We evaluated the ability of 13N-ammonia positron emission tomography (PET)/computed tomography (CT) to locate and distinguish pituitary tissue from PAs.Materials and MethodsForty-eight patients (four with prolactinoma, 10 with Cushing's disease, 12 with acromegaly, and 22 with nonfunctional PAs) prospectively underwent magnetic resonance imaging (MRI), 13N-ammonia PET/CT, 18F-FDG PET/CT, prior to surgery.ResultsPituitary position could be determined in 31 (64.5%) patients by 13N-ammonia PET/CT, and by MRI in 26 (54.2%) patients. It was detected by 13N-ammonia PET/CT and MRI in eight of eight patients (100%) with pituitary microadenoma, tumor maximum diameter (TMD)
       
  • Whole Lesion Histogram Analysis Derived From Morphological MRI Sequences
           Might be Able to Predict EGFR- and Her2-Expression in Cervical Cancer
    • Abstract: Publication date: Available online 11 October 2018Source: Academic RadiologyAuthor(s): Hans-Jonas Meyer, Gordian Hamerla, Anne Kathrin Höhn, Alexey SurovRationale and ObjectivesHistogram analysis is an imaging analysis in which a whole tumor can be assessed, and every voxel of a radiological image is issued into a histogram. Thereby, statistically information about tumor can be obtained. The purpose of the study was to analyze possible relationships between histogram parameters derived from conventional MRI sequences and several histopathological features in cervical squamous cell carcinomas.MethodsA total of 18 female patients (age range 32–79 years) with squamous cell cervical carcinoma were retrospectively enrolled into the study. In all cases, pelvic MRI with a clinically protocol was performed. Histogram analysis was performed as a whole lesion measurement, calculating several percentils, minimum, mean, median, mode, maximum, kurtosis, skewness, and entropy. Histopathological parameters included expression of epidermal-growth factor (EGFR), vascular endothelial growth factor, hypoxia-inducible factor 1-alpha, Her2, and Histone 3. Spearman's correlation coefficient was used to analyze associations between investigated parameters.ResultsSeveral pre- and postcontrast derived T1-weighted parameters correlated inversely with EGFR expression. For precontrast T1-weighted images, the strongest correlation was found for p90 (ρ = −0.77, p = 0.004). For postcontrast T1-weighted images, the strongest correlation was observed for minimum (ρ = −0.64, p = 0.021). Several parameters derived from T2-weighted images were statistically significant different between Her2-positive and Her2 negative tumors. Skewness had the best p-value ( p = 0.004).ConclusionsHistogram analysis parameters of T1-weighted and T2-weighted images reflect HER2 status and EGFR expression in cervical cancer. Histogram parameters cannot predict cell count, proliferation index, or angiogenesis related histopathological features.
       
  • Continued Validation of Ultrasound Guidance Targeting Tasks: Assessment of
           Internal Structure
    • Abstract: Publication date: Available online 11 October 2018Source: Academic RadiologyAuthor(s): J.F. Nitsche, S. Conrad, S. Hoopes, M. Carrel, K. Bebeau, B.C. BrostRationale and ObjectivesWe previously demonstrated validity evidence for our novel ultrasound-guided invasive procedure targeting tasks in the content, response process, relations with other variables, and consequences validity domains. Here, we investigate their internal structure by assessing their interrater, intrarater, and test–retest reliability.MethodsIn thisInstitutional Review Board approved nonrandomized interventional trial first year medical students performed our previously described dowel and straw ultrasound guidance targeting tasks as a pretest. Afterward, the training group had four weekly 1-hour training sessions. The control group had no further training. Both groups then had a posttest for both tasks. The training group was re-evaluated 2 and 5 months later. Completion time in seconds, errors, and error adjusted time (5 seconds penalty/error) were recorded. Pretest and posttest performance was compared within groups, and the amount of improvement from pretest to posttest was compared between groups. Interrater, intrarater, and test–retest interclass correlation coefficients (ICC) were calculated.ResultsAlthough some improvements from pretest to posttest were seen in both groups, greater improvements were seen in the training group. This skill was retained for at least several months. The interrater and intrarater ICCs were excellent (range 0.83–0.93). The test–retest ICCs were good to excellent in all but one performance measure (0.50–0.78).ConclusionStudent performance on the targeting tasks improved markedly after training and persisted for several months. The interrater and intrarater reliability were excellent, while the test–retest reliability was good. This provides additional validity evidence for our novel ultrasound-guided invasive procedure targeting curriculum.
       
  • Response to: Letter to the Editor Regarding Survey Research: A Primer for
           the Academic Radiologist
    • Abstract: Publication date: Available online 11 October 2018Source: Academic RadiologyAuthor(s): Prasad R Shankar, Katherine E Maturen
       
  • Automated Test-Item Generation System for Retrieval Practice in Radiology
           Education
    • Abstract: Publication date: Available online 10 October 2018Source: Academic RadiologyAuthor(s): Gowthaman Gunabushanam, Caroline R. Taylor, Mahan Mathur, Jamal Bokhari, Leslie M. ScouttObjectiveTo develop and disseminate an automated item generation (AIG) system for retrieval practice (self-testing) in radiology and to obtain trainee feedback on its educational utility.Materials and MethodsAn AIG software program (Radmatic) that is capable of generating large numbers of distinct multiple-choice self-testing items from a given “item-model” was created. Instead of writing multiple individual self-testing items, an educator creates an “item-model” for one of two distinct item styles: true/false knowledge based items and image-based items. The software program then uses the item model to generate self-testing items upon trainee request. This internet-based system was made available to all radiology residents at our institution in conjunction with our didactic conferences. After obtaining institutional review board approval and informed consent, a written survey was conducted to obtain trainee feedback.ResultsTwo faculty members with no computer programming experience were able to create item-models using a standard template. Twenty five of 54 (46%) radiology residents at our institution participated in the study. Twelve of these 25 (48%) study participants reported using the self-testing items regularly, which correlated well with the anonymous website usage statistics. The residents’ overall impression and satisfaction with the self-testing items was quite positive, with a score of 7.89 ± 1.91 (mean ± SD) out of 10. Lack of time and email overload were the main reasons provided by residents for not using self-testing items.ConclusionAIG enabled self-testing is technically feasible, and is perceived positively by radiology residents as useful to their education.
       
  • Influence of Data Parsing on Contrast Enhanced Ultrasound Exams
    • Abstract: Publication date: Available online 10 October 2018Source: Academic RadiologyAuthor(s): Jingzhi Li, Laurence Needleman, Ji-Bin Liu, Andrej Lyshchik, Flemming Forsberg, Maria Stanczak, James McAlister, John EisenbreyRationale and ObjectivesTo explore the influence of data parsing (either selection of frames at set time intervals or by an experienced sonographer) of contrast-enhanced ultrasound (CEUS) exams on physician diagnoses and confidence levels.Materials and MethodsForty consecutive CEUS exams consisting of 10 cases each of indeterminate liver lesions, indeterminate renal lesions, renal cell carcinoma postablation follow-up, and hepatocellular carcinoma postchemoembolization follow-up were selected for analysis. Exams were parsed into sets consisting of five images selected by the performing sonographer and sets containing systematically stored frames every 10, 30, and 60 seconds. Three blinded physicians then reviewed the cine loop and each set of images in randomized order and provided a diagnosis and confidence level.ResultsFor all clinical applications investigated, no statistically significant differences in diagnostic performance measures or reader confidence were observed between review of the entire cine loop and images selected by the performing sonographer (p> 0.42). Diagnostic performance at 10-second intervals did not show statically significant changes compared to the full cine loop review for all applications (p> 0.18), although reader confidence decreased. At 30–60-second intervals, both diagnostic performance and reader confidence showed statistically significant reduction compared to review of the full cine loop (p < 0.045).ConclusionsTransfer and review of large cine loops from CEUS exams represent a potential barrier to adoption within the United States workflows. This study demonstrates that images selected by a performing trained sonographer may provide the same value without the review time and data storage costs needed for full cine loop review. Parsing by time points reduced reader confidence and diagnostic performance.
       
  • Separating High-Z Oral Contrast From Intravascular Iodine Contrast in an
           Animal Model Using Dual-Layer Spectral CT
    • Abstract: Publication date: Available online 9 October 2018Source: Academic RadiologyAuthor(s): Todd C. Soesbe, Matthew A. Lewis, Khaled Nasr, Lakshmi Ananthakrishnan, Robert E. LenkinskiRationale and ObjectivesTo show that water and iodine two-material decomposition images from dual-layer dual-energy spectral X-ray computed tomography (DECT) can be used to separate intravascular iodine contrast from simultaneously administered oral tantalum, tungsten, or rhenium contrast in an animal model.Materials and MethodsIn this Institutional Animal Care and Use Committee approved study, four female Fischer rats were given simultaneous intravenous and oral X-ray computed tomography contrast. Intravenous iodine contrast was administered via tail vein injection. Oral barium, tantalum, tungsten, or rhenium contrast was administered via gavage. The animals were imaged on a dual-layer DECT system at 120 kVp. Water and iodine two-material decomposition images (water equivalent and iodine equivalent images) were used for qualitative analysis. Computer simulations were performed using a customized DECT simulator to better understand why certain high-Z elements disappear in the iodine equivalent images and what is the theoretical range of elements with this property.ResultsThe iodine and barium contrast appeared only in the iodine equivalent images and could not be differentiated from each other. However, the tantalum, tungsten, and rhenium contrast only appeared in the water equivalent images. This allowed iodine contrast in the bowel wall to be easily segmented from tantalum, tungsten, and rhenium contrast in the bowel lumen. Simulations confirmed that certain high-Z elements will have pixel values of ≤0mg iodine/mL in the iodine equivalent images due to a K-edge effect associated with DECT systems.ConclusionsDual-layer DECT can separate iodine from certain high-Z elements using water equivalent and iodine equivalent images with an increased element range compared to other DECT systems. This K-edge effect could promote the development and approval of new high-Z contrast agents for DECT.
       
  • Radiology Research at the Cutting Edge for a Better Future
    • Abstract: Publication date: Available online 9 October 2018Source: Academic RadiologyAuthor(s): Linda Probyn
       
  • Discrimination of Pulmonary Nodule Volume Change for Low- and
           High-contrast Tasks in a Phantom CT Study with Low-dose Protocols
    • Abstract: Publication date: Available online 3 October 2018Source: Academic RadiologyAuthor(s): Marios A. Gavrielides, Qin Li, Rongping Zeng, Benjamin Paul Berman, Berkman Sahiner, Qi Gong, Kyle J. Myers, Gino DeFilippo, Nicholas PetrickRationale and ObjectivesThe quantitative assessment of volumetric CT for discriminating small changes in nodule size has been under-examined. This phantom study examined the effect of imaging protocol, nodule size, and measurement method on volume-based change discrimination across low and high object to background contrast tasks.Materials and MethodsEight spherical objects ranging in diameter from 5.0 mm to 5.75 mm and 8.0 mm to 8.75 mm with 0.25 mm increments were scanned within an anthropomorphic phantom with either foam-background (high-contrast task, ∼1000 HU object to background difference)) or gelatin-background (low-contrast task, ∼50 to 100 HU difference). Ten repeat acquisitions were collected for each protocol with varying exposures, reconstructed slice thicknesses and reconstruction kernels. Volume measurements were obtained using a matched-filter approach (MF) and a publicly available 3D segmentation-based tool (SB). Discrimination of nodule sizes was assessed using the area under the ROC curve (AUC).ResultsUsing a low-dose (1.3 mGy), thin-slice (≤1.5 mm) protocol, changes of 0.25 mm in diameter were detected with AU = 1.0 for all baseline sizes for the high-contrast task regardless of measurement method. For the more challenging low-contrast task and same protocol, MF detected changes of 0.25 mm from baseline sizes ≥5.25 mm and volume changes ≥9.4% with AUC≥0.81 whereas corresponding results for SB were poor (AUC within 0.49-0.60). Performance for SB was improved, but still inconsistent, when exposure was increased to 4.4 mGy.ConclusionThe reliable discrimination of small changes in pulmonary nodule size with low-dose, thin-slice CT protocols suitable for lung cancer screening was dependent on the inter-related effects of nodule to background contrast and measurement method.
       
  • Robustness of Textural Features to Predict Stone Fragility Across Computed
           Tomography Acquisition and Reconstruction Parameters
    • Abstract: Publication date: Available online 2 October 2018Source: Academic RadiologyAuthor(s): Taylor Moen, Andrea Ferrero, Cynthia McColloughRationale and ObjectivesPrevious studies have demonstrated that quantitative relationships exist between stone fragility at lithotripsy and morphological features extracted from computed tomography (CT) scans. The goal of this study was to determine if variations in scanner model, patient size, radiation dose, or reconstruction parameters impact the accuracy of the prediction of renal stone fragility in an in vitro model.Materials and MethodsSixty-seven kidney stones were scanned using routine single and dual energy stone protocols, mimicking average, and large patient habitus. Low dose scans were also performed. Each scan was reconstructed with routine protocol parameters, and with thinner (0.6 mm) or thicker (3mm) images, two different reconstruction kernels, and iterative reconstruction at two strengths. Fragilityof each stone was measured in a controlled ex vivo experiment. A single predictive model was developed from a reference CT protocol configuration and applied to data from each CT acquisition and reconstruction parameter tested to obtain estimated stone comminution times.ResultsNone of the investigated protocols showed a significant variation in the accuracy of stone fragility classification, except for the ones with the most aggressive iterative reconstruction and/or with thicker images. In these protocols, a number of stone fragility assessments changed from fragile to hard (or vice versa), compared to their ground truth measurement.ConclusionPrediction accuracy of stone fragility models developed from CT data is robust to expected variations in CT stone protocols used for quantification tasks. This finding facilitates their future adoption to different clinical practices.
       
  • Relationship Between Tube Voltage and Physical Image Quality of Pulmonary
           Nodules on Chest Radiographs Obtained Using the Bone-Suppression Technique
           
    • Abstract: Publication date: Available online 28 September 2018Source: Academic RadiologyAuthor(s): Satoshi Takagi, Tatsuya Yaegashi, Masayori IshikawaRationale and ObjectivesImage quality of chest radiographs is affected by tube voltage. This study aimed to clarify the relationship between tube voltage and physical image quality of pulmonary nodules on bone-suppressed chest radiographs.Materials and MethodsAn anthropomorphic chest phantom and a spherical simulated nodule, with a 12-mm diameter and approximately +100 Hounsfield units were used. The lung field of the phantom was divided into three areas, based on the overlap with the ribs in the chest radiograph. Ten positions of the simulated nodule were defined in each area. One hundred and twenty chest radiographs were acquired using four tube voltages (70 kVp, 90 kVp, 110 kVp, and 130 kVp) for a total of 30 nodule positions and were processed to create bone-suppressed images. Differences in contrast and contrast-to-noise ratio (CNR) were analyzed for all pairs of the four tube voltages using a two-sided Wilcoxon signed-rank test.ResultsIn the area not overlapping with ribs, a statistically significant difference was observed only in contrast between tube voltage of 70 kVp and 90 kVp (p = 0.01). In the area overlapping with one or two ribs, the contrast and CNR tended to be higher at a lower tube voltage. In particular, the p values between the contrast at 70 kVp and that at the other three tube voltage settings were less than 0.01.ConclusionFor a relatively dense nodule, the contrast and CNR in the bone-suppressed chest radiograph were significantly improved with lower tube voltage in the lung field overlapping with the ribs.
       
  • Can Realistic Liver Tissue Surrogates Accurately Quantify the Impact of
           Reduced-kV Imaging on Attenuation and Contrast of Parenchyma and
           Lesions'
    • Abstract: Publication date: Available online 28 September 2018Source: Academic RadiologyAuthor(s): Andre Euler, Justin Solomon, Paul F. FitzGerald, Ehsan Samei, Rendon C. NelsonRationale and ObjectivesTo assess if a liquid tissue surrogate for the liver (LTSL) can emulate contrast-enhanced liver parenchyma and lesions and quantify the impact of reduced-kV imaging as a function of lesion contrast, phase of enhancement, and phantom size.Materials and MethodsFirst, CT attenuation of LTSL- and water-iodine solutions were measured as a function of iodine concentration and tube potential. For each solution, the iodine concentration was determined to emulate liver parenchyma at 120kV. CT attenuation for both solutions was predicted for different tube potentials and compared to published patient data. Second, liver parenchyma in late arterial phase (LA: +92 HU at 120 kV) and portal venous phase (PV: +112 HU at 120 kV) was emulated using LTSL-iodine and a two-size phantom. Fourteen setups of hyper- and hypoattenuating lesions (lesion-to-parenchyma contrast (CLP) = −50 to +50HU) were created. Each combination of CLP, phase, and size was imaged at 80, 100, 120, and 140kV at constant radiation dose. CT attenuation, CLP, and lesion-to-parenchyma contrast-to-noise ratio (CNRLP) were assessed and compared to a theoretical model.ResultsLTSL-iodine more accurately emulated the CT attenuation of liver parenchyma across different tube potentials compared to water-iodine solutions. The theoretical model was confirmed by the empirical measurements using LTSL-iodine solutions: attenuation, CLP, and CNRLP increased when the tube potential decreased (p < 0.001). This trend was independent of lesion contrast, phase, and size. The absolute improvement in CLP and CNRLP, however, was inversely related to the magnitude of CLP at 140kV.ConclusionLTSL accurately emulated the energy-dependent CT attenuation characteristics of contrast-enhanced liver parenchyma and lesions. The relative improvement in CLP and CNRLP by applying reduced-kV imaging was independent of lesion contrast, phase, and size while the absolute improvement decreased for low-contrast lesions.
       
  • Ultrafast Dynamic Contrast-Enhanced Breast MRI: Kinetic Curve Assessment
           Using Empirical Mathematical Model Validated with Histological Microvessel
           Density
    • Abstract: Publication date: Available online 28 September 2018Source: Academic RadiologyAuthor(s): Naoko Mori, Hiroyuki Abe, Shunji Mugikura, Chiaki Takasawa, Satoko Sato, Minoru Miyashita, Yu Mori, Federico D. Pineda, Gregory S. Karczmar, Hajime Tamura, Shoki Takahashi, Kei TakaseRationale and ObjectivesTo evaluate whether parameters from empirical mathematical model (EMM) for ultrafast dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) correlate with histological microvessel density (MVD) in invasive breast cancer.Materials and MethodsNinety-eight consecutive patients with invasive breast cancer underwent an institutional review board-approved ultrafast DCE-MRI including a pre- and 18 postcontrast whole breast ultrafast scans (3 seconds) followed by four standard scans (60 seconds) using a 3T system. Region of interest was placed within each lesion where the highest signal increase was observed on ultrafast DCE-MRI, and the increase rate of enhancement was calculated as follows: ΔS = (SIpost − SIpre)/SIpre. The kinetic curve obtained from ultrafast DCE-MRI was analyzed using a truncated EMM: ΔS(t) = A(1 − e−αt), where A is the upper limit of the signal intensity, α (min−1) is the rate of signal increase. The initial slope of the kinetic curve is given by Aα. Initial area under curve (AUC30) and time of initial enhancement was calculated. From the standard DCE-MRI, the initial enhancement rate (IER) and the signal enhancement ratio (SER) were calculated as follows: IER = (SIearly − SIpre)/SIpre, SER = (SIearly − SIpre)/(SIdelayed − SIpre). The parameters were compared to MVD obtained from surgical specimens.ResultsA, α, Aα, AUC30, and time of initial enhancement significantly correlated with MVD (r = 0.29, 0.40, 0.51, 0.43, and −0.32 with p = 0.0027, p < 0.0001, p < 0.0001, p < 0.0001, and p = 0.0012, respectively), whereas IER and SER from standard DCE-MRI did not.ConclusionThe parameters of the EMM, especially the initial slope or Aα, for ultrafast DCE-MRI correlated with MVD in invasive breast cancer.
       
  • Reliability of MRI-Derived Depth of Invasion of Oral Tongue Cancer
    • Abstract: Publication date: Available online 27 September 2018Source: Academic RadiologyAuthor(s): Ryuji Murakami, Shinya Shiraishi, Ryoji Yoshida, Junki Sakata, Keisuke Yamana, Akiyuki Hirosue, Yoshikazu Uchiyama, Hideki Nakayama, Yasuyuki YamashitaRationale and ObjectiveTo evaluate the inter-rater reliability of the magnetic resonance imaging (MRI)-derived depth of invasion (
      DOI ) and the agreement between MRI and pathological measurements of oral tongue cancer.Materials and MethodsThe institutional review board approved this retrospective study. The study population consisted of 29 patients with clinical T2N0 oral tongue cancer treated by surgery. Routine pretreatment MRI was performed on a 3T superconducting imager. Two raters with 23 and 18years of head-and-neck MRI experience, respectively, independently chosen MRI sequences for each patient, then delineate the tumor, and then used three protocols to measure the MRI-derived
      DOI : the axial reconstructed thickness (method 1), the axial invasive portion (method 2), and the coronal invasive portion (method 3). Then they consensually selected the optimal among the three methods for each patient; it was designated method 4. The Bland-Altman plots, intraclass correlation coefficients (ICCs), and the paired samples test were used. According to the median follow-up of 41 months, the relationship between the MRI-derived
      DOI and nodal recurrence was also investigated.ResultsThe inter-rater reliability of methods 2 and 4 was excellent (ICC of 0.829 and 0.807, respectively). The correlation between MRI and pathological measurements was good for method 4 (ICC of 0.611), however, all measurements recorded on MRI were 2–3mm larger than on pathology. No patients whose MRI-derived
      DOI was less than 5mm suffered nodal recurrence.ConclusionThe MRI-derived
      DOI was valuable for the preoperative staging. The optimal measurement method should be selected on a case-by-case basis.
       
  • Interobserver Agreement and Positivity of PI-RADS Version 2 Among
           Radiologists with Different Levels of Experience
    • Abstract: Publication date: Available online 27 September 2018Source: Academic RadiologyAuthor(s): Thais Caldara Mussi, Fernando Ide Yamauchi, Cássia Franco Tridente, Adriano Tachibana, Victor Martins Tonso, Débora Rachello Recchimuzzi, Layra Ribeiro de Souza Leão, Daniel Calich Luz, Tatiana Martins, Ronaldo Hueb BaroniRationale and ObjectivesTo evaluate interobserver agreement of Prostate Imaging Reporting and Data System (PI-RADS) v2 category among radiologists with different levels of experience. The secondary objective was to evaluate the positivity for significant cancer among each category (splitting category 4 into two) and among different lesion sizes.Materials and MethodsInstitutional review board and ethics comitee approved retrospective study. Eight radiologists with different levels of experienced in prostatic magnetic resonance imaging—two more experienced, four with intermediate experience, and two abdominal radiology fellows—interpreted 160 lesions. Reference standard was fusion-targeted biopsy. Percentage agreement, k coefficients, and analysis concordance were used.ResultsCoefficient of concordance according to categories was 0.71 considering both zones, 0.72 for peripheral zone (PZ) and 0.44 for peripheral zone (TZ). Agreement for PI-RADS score of 3 or greater was 0.48 in PZ and 0.57 in TZ. Tumor positivity rates were 54.3% and 66.0% for PI-RADS 3 + 1 and 4 for PZ, respectively; and 25.0 and 49.2% for PI-RADS 3 + 1 and 4 for TZ, respectively (p < 0.001 in both analysis). Lesions
       
  • A Comparison of Two Hyperpolarized 129Xe MRI Ventilation Quantification
           Pipelines: The Effect of Signal to Noise Ratio
    • Abstract: Publication date: Available online 27 September 2018Source: Academic RadiologyAuthor(s): Mu He, Wei Zha, Fei Tan, Leith Rankine, Sean Fain, Bastiaan DriehuysRationaleHyperpolarized 129Xe MRI enables quantitative evaluation of regional ventilation. To this end, multiple classifiers have been proposed to determine ventilation defect percentage (VDP) as well as other cluster populations. However, consensus has not yet been reached regarding which of these methods to deploy for multicenter clinical trials. Here, we compare two published classification techniques–linear-binning and adaptive K-means–to establish their limits of agreement and their robustness against reduced signal-to-noise ratio (SNR).MethodsA total of 29 subjects (age: 38.4 ± 19.0 years) were retrospectively identified for inter-method comparison. For each 129Xe ventilation image, 7 images with reduced SNR were generated with equal decrements relative to the native SNR. All 8 sets of images were then analyzed using both methods independently to classify all lung voxels into four clusters: VDP, low-, medium-, and high-ventilation-percentage (LVP, MVP and HVP). For each cluster, the percentage of the lung it comprised was compared between the two methods, as well as how these values persisted as SNR was degraded.ResultsThe limits of agreement for calculating VDP were [+0.2%, +4.0%] with a +1.5% bias for binning relative to K-means. However, the inter-method agreement for the other clusters was moderate, with biases of −5.7%, 8.1%, and −4.0% for LVP, MVP, and HVP, respectively. As SNR decreased below ∼4, both methods began reporting values that deviated substantially from the native image. By requiring VDP to remain within ≤1.8% of that calculated from the native image, the minimum tolerable SNR values were 2.4 ± 1.0 for the linear-binning, and 3.5 ± 1.5 for the K-means.ConclusionsBoth methods agree well in quantifying VDP, but agreement for LVP and MVP remains variable. We suggest a required SNR threshold be two standard deviations above the minimum value of 3.5 ± 1.5 for robust determination of VDP, suggesting a minimum SNR of 6.6. However, robust quantification of the ventilated clusters required an SNR of 13.4.
       
  • Correlation Between Intravoxel Incoherent Motion and Dynamic
           Contrast-Enhanced Magnetic Resonance Imaging Parameters in Rectal Cancer
    • Abstract: Publication date: Available online 27 September 2018Source: Academic RadiologyAuthor(s): Hongliang Sun, Yanyan Xu, Qiaoyu Xu, Jianghui Duan, Haibo Zhang, Tongxi Liu, Lu Li, Queenie Chan, Sheng Xie, Wu WangRationale and ObjectivesThis study aimed to determine the correlation between intravoxel incoherent motion (IVIM) and multiphase dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters in patients with rectal cancer.Materials and MethodsNinety-seven patients with rectal cancer were included in this study. All pelvic MRI examinations were performed in a 3.0 T MR unit, including diffusion-weighted imaging with 16 b values, DCE-MRI with two different flip angles (5° and 10°, respectively), and T1-fast field echo sequences as the reference. The IVIM perfusion-related parameters (f, perfusion fraction; D*, pseudo-diffusion coefficient; f·D*, the multiplication of the two parameters) were calculated by biexponential analysis. Quantitative DCE-MRI parameters were transfer constant (Ktrans) between blood plasma and extravascular extracellular space), Kep (rate between extravascular extracellular space and blood plasma), Ve (extravascular volume fraction), Vp (plasma volume fraction), and area under the gadolinium concentration curve. Interobserver agreements were evaluated using the intraclass correlation coefficient and Bland–Altman analysis. A p value
       
  • Effects of Radiation Dose Reduction on Diagnostic Accuracy of Abdominal CT
           in Young Adults with Suspected Acute Diverticulitis: A Retrospective
           Intraindividual Analysis
    • Abstract: Publication date: Available online 26 September 2018Source: Academic RadiologyAuthor(s): Sven S. Walter, Michael Maurer, Corinna Storz, Jakob Weiss, Rami Archid, Fabian Bamberg, Jong Hyo Kim, Konstantin Nikolaou, Ahmed E. OthmanRationale and ObjectivesTo assess the effects of radiation dose reduction on image quality and diagnostic accuracy of abdominal computed tomography (CT) in young adults with suspected acute diverticulitis.Materials and MethodsFifty-four patients ≤40years who received contrast-enhanced abdominal CT for suspected acute diverticulitis were included. Low-dose CT (LDCT) datasets (25%, 50%, and 75% of the original dose) were generated using sinogram synthesis and quantum noise modeling. A five-point scale was used to assess images qualitatively (overall image quality, noise, artefacts, and sharpness) and for diagnostic confidence (5 being the best possible outcome). Furthermore, the diagnostic accuracy was determined for the presence of acute diverticulitis.ResultsAmong 54 patients (mean age: 35.2 ± 5.3years, 77.8% male), the prevalence of acute diverticulitis was high (57.4%). Subjective image quality was highest for original datasets and lowest for LDCT datasets with 25% of the original dose (median [interquartile range]: 5 [5] vs. 3 [2–3], p < 0.001). Diagnostic confidence was high for all datasets down to 50% of the original dose, while 25% LDCT datasets were associated with a significantly decreased diagnostic confidence (p < 0.001). Diagnostic accuracy was high for all LDCT and original datasets (sensitivity: 100%, negative predictive value [NPV]: 100% for 75% and 100% dose levels; sensitivity: 96.8%, NPV: 95.8% for 50% dose level; sensitivity: 93.6%, NPV: 91.7% for 25% dose level, respectively). Inter-rater agreement regarding the detection of diverticulitis was almost perfect at doses ≥50% (kappa:>0.81), while lower for datasets of 25% of the original radiation dose agreement (kappa: 0.67–0.78).ConclusionRadiation dose reduction down to 50% of the original radiation exposure permits high image quality, diagnostic confidence, and accuracy for the assessment of acute diverticulitis in abdominal CT in young adults without the use of iterative reconstruction algorithms.
       
  • More Frequent Follow-up CT Scans in Postsurgical Resection Patients Than
           in Postendoscopic Resection Patients of Early Gastric Cancers:
           Impracticality of CTs for Mucosal Cancer
    • Abstract: Publication date: Available online 26 September 2018Source: Academic RadiologyAuthor(s): Moon Hyung Choi, Seung Eun Jung, Young Joon Lee, Seung Bae YoonRationale and objectivesThe aim of this study was to compare the utility and timing of computed tomography (CT) in the detection of recurrent tumors between patients after surgical and endoscopic resections for early gastric cancer (EGC).Materials and MethodsA total of 670 patients after surgical (n = 535) and endoscopic (n = 135) resections for EGC between 2007 and 2009 were enrolled. The mean numbers of CT and endoscopy between both treatment groups were compared. The mean and cumulative dose length products of CT examinations were calculated. The modality that detected recurrence was compared between the two groups using the Pearson chi-square test.ResultsThe mean interval of CT was significantly shorter and the mean number of CTs was significantly larger in the surgical resection group than in the endoscopic resection group. All 34 gastric recurrences were diagnosed by endoscopy. All seven extragastric recurrences occurred in patients treated for EGC with submucosal invasion. Six extragastric recurrences were detected by CT out of a total of 5417 CT scans. The average cumulative dose length product was significantly higher in the surgical group than in the endoscopic resection group (P = 0.004).ConclusionFollow-up CTs were performed more frequently in patients after surgical resection than in patients after endoscopic resection of EGCs. However, CT scans were not effective in detecting recurrent tumors after either treatment methods, especially for patients treated for mucosal gastric cancer.
       
  • Prevalence and Types of Aortic Arch Variants and Anomalies in Congenital
           Heart Diseases
    • Abstract: Publication date: Available online 25 September 2018Source: Academic RadiologyAuthor(s): Ahmed M. Tawfik, Donia M. Sobh, Germeen A. Ashamallah, Nihal M. BatoutyRationale and ObjectivesAortic arch (AA) variants and anomalies are important to recognize in patients with congenital heart disease (CHD) before surgery or intervention. The aim was to study the prevalence of AA anomalies and variants in patients with CHD compared to a control group. The secondary outcome was to report the associations between common variations of AA and specific types of CHD.Materials and MethodsAfter institutional review board approval, computed tomography studies of 352 CHD patients and control group of 400 consecutive computed tomography scans of the thorax were evaluated. The AA was assigned to one of seven common types, and their distribution was compared between CHD and control. The distribution of the AA anomalies and variants was evaluated as regard specific types of CHD and the visceroatrial situs.ResultsNormal three-vessel branching pattern was the commonest in both groups, but was present in only 50.5% in the CHD compared to 68.5% in the control group, p < 0.00001. Right AA and aberrant right subclavian artery were significantly more common in CHD than control group (18.1% versus 0.25%, p < 0.00001) and (4.5% versus 0.25%, p = 0.0001), respectively. Direct aortic origin of left vertebral artery was insignificantly more common in CHD group (4.2% versus 2.7%, p = 0.258). Brachiobicephalic trunk was significantly more common in control than CHD group (27.7% versus 19.3%, p = 0.007).ConclusionNormal three-vessel AA was significantly less common in CHD. AA anomalies (right arch and aberrant right subclavian) were more common in CHD than control, while AA variants (brachiobicephalic trunk and direct aortic origin of left vertebral artery) were not.
       
  • Iodine density Changes in Hepatic and Splenic Parenchyma in Liver
           Cirrhosis with Dual Energy CT (DECT): A Preliminary Study
    • Abstract: Publication date: Available online 24 September 2018Source: Academic RadiologyAuthor(s): Jian Dong, Fuliang He, Lei Wang, Zhendong Yue, Tingguo Wen, Rengui Wang, Fuquan LiuPurposeTo investigate the hemodynamic changes in liver cirrhosis by comparing iodine density in hepatic and splenic parenchyma with 8 cm detector dual energy CT (DECT).Materials and MethodsForty-six consecutive patients with liver cirrhosis and 22 healthy volunteers were recruited in this study, and they were all performed contrast enhanced examination with 8 cm detector DECT. All raw data were reconstructed with 1.25 mm slice thickness, Iodine density (in milligrams per milliliter) were measured on iodine-based material decomposition images. Quantitative indices of iodine density (ID), including normalized ID of liver parenchyma for arterial phase (NIDLAP), ID of liver parenchyma for venous phase (IDLVP), ID of splenic parenchyma for arterial phase (IDSAP), ID of splenic parenchyma for venous phase (IDSVP), ID of portal vein in venous phase (IDPVP) and Liver arterial iodine density fraction (AIF) were measured and compared between two groups. The correlation between Child-Pugh grade and other quantitative indices were calculated, with statistical significance as P0.05), (2) higher iodine density of NIDLAP, IDSVP, IDPVP and AIF, and lower NIDSAP (all P
       
  • Ultrasound-Diagnosed Nonalcoholic Fatty Liver Disease Independently
           Predicts a Higher Risk of Developing Diabetes Mellitus in Nonoverweight
           Individuals
    • Abstract: Publication date: Available online 23 September 2018Source: Academic RadiologyAuthor(s): Liang WangRationale and ObjectivesThis study was aimed to evaluate the independent value of ultrasound-diagnosed nonalcoholic fatty liver disease (us-NAFLD), as a surrogate imaging marker of the pathologic entity of NAFLD, in predicting incident diabetes mellitus (DM) in nonoverweight individuals.Materials and MethodsA total of 10,064 participants who had a body mass index
       
  • Raising the BAR: Challenges, Opportunities, and Hidden Gems in Radiology
           Education
    • Abstract: Publication date: Available online 22 September 2018Source: Academic RadiologyAuthor(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.
       
  • The Time to and Type of Pancreatic Cancer Recurrence after Surgical
           Resection: Is Prediction Possible'
    • Abstract: Publication date: Available online 22 September 2018Source: Academic RadiologyAuthor(s): Jelena Djokić Kovač, Philipp Mayer, Thilo Hackert, Miriam KlaussRationale and ObjectivesTo evaluate factors predicting pancreatic cancer recurrence, and to determine the most common appearance of tumor relapse.Materials and MethodsNinety patients with recurrent pancreatic cancer were retrospectively included in the study. 74.4% had pancreatic head tumors (group 1) and 25.6% pancreatic body and/or tail tumor (group 2). The tumor localization, operative technique, TNM stage, the R-status, tumor grade, lymphovascular, and perineural invasion were recorded. Location of local tumor recurrence, lymph node recurrence, or organ metastases were analyzed on the basis of follow-up CT imaging.ResultsMean recurrence time was 17.4 ± 13.2 months. The most common recurrence type was local recurrence (84.4%), followed by lymph node (15.5%), liver (14.4%), and lung metastasis (6.7%). The predominant site of local recurrence in pancreatic head tumors was close to superior mesenteric artery, common hepatic artery, and/or celiac artery (57.4%), followed by area defined by portal vein, inferior vena cava, CA or superior mesenteric artery (31.2%). Patients with pancreatic body and/or tail carcinoma had higher incidence (p = 0.003) of metastatic disease comparing to pancreatic head tumors, while resection margin was the most common type of local tumor recurrence, seen in 46.7% cases versus 8.2% of patients with pancreatic head tumors (p < 0.001).ConclusionThe most common recurrence type in patients with resected pancreatic carcinoma was local recurrence along cardinal arteries. The localization of primary tumor influences the type of tumor relapse and site of local recurrence.
       
  • Design and Validation of a Peer-Teacher-Based Musculoskeletal Ultrasound
           Curriculum
    • Abstract: Publication date: Available online 19 September 2018Source: Academic RadiologyAuthor(s): Netanel S. Berko, Jenna N. Le, Beverly A. Thornhill, Dan Wang, Abdissa Negassa, E. Stephen Amis, Mordecai KoenigsbergRationale and ObjectivesTo design and validate a peer-teacher based musculoskeletal ultrasound curriculum for radiology residents.Materials and MethodsA musculoskeletal ultrasound curriculum with hands-on scanning workshops was designed for radiology residents. Prior to the workshops, several residents received 3 hours of hands-on training in ultrasound scanning technique which was overseen by an attending musculoskeletal radiologist; these “peer teachers” then led small-group hands-on scanning during the workshops. Participants performed diagnostic ultrasound examinations at the conclusion of the workshops to assess skill acquisition and 2 months following the workshops to quantify skill retention. Participants also completed surveys to determine confidence in performing musculoskeletal ultrasound examinations. Median scores and interquartile range (25–75%) were calculated, and t test was used to compare results.ResultsThirty seven residents from all years of training and six senior resident or fellow peer teachers participated in four workshops. Diagnostic ultrasound images were obtained in 100% at the conclusion of the workshop and in 79% 2 months later. Prior to the workshops, residents reported low level of musculoskeletal ultrasound knowledge (median 2, interquartile ranges 1–2), and low confidence in performing (1, 1–2) and interpreting (1, 1–2) musculoskeletal ultrasound examinations. There was a significant increase in knowledge (3, 3–4) and confidence performing (3, 3–4) and interpreting (3, 3–4) studies following the workshops (p < 0.001 for all comparisons).ConclusionHands-on musculoskeletal ultrasound workshops, utilizing a peer teacher led small group format is an effective method of teaching scanning skills to residents. There was excellent skill acquisition, good skill retention, and significant increase in confidence performing and interpreting these studies following completion of the curriculum.
       
  • Why Radiology Residents Experience Burnout and How to Fix It
    • Abstract: Publication date: Available online 19 September 2018Source: Academic RadiologyAuthor(s): Dexter Mendoza, Frederic J. Bertino
       
  • Structural and Functional Pulmonary Magnetic Resonance Imaging in
           Pediatrics—From the Neonate to the Young Adult
    • Abstract: Publication date: Available online 15 September 2018Source: Academic RadiologyAuthor(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.
       
  • A Reliability Comparison of Cone-Beam Breast Computed Tomography and
           Mammography: Breast Density Assessment Referring to the Fifth Edition of
           the BI-RADS Atlas
    • Abstract: Publication date: Available online 14 September 2018Source: Academic RadiologyAuthor(s): Yue Ma, Yang Cao, Aidi Liu, Lu Yin, Peng Han, Haijie Li, Xiaohua Zhang, Zhaoxiang YeRationale and ObjectivesTo evaluate the reliability of cone-beam breast computed tomography (CBBCT) in visual assessment of breast density referring to the fifth edition of the Breast Imaging Reporting and Data System compared to digital mammography.Materials and MethodsBreast density assessments of 130 female patients were performed by five radiologists referring to the fifth edition of Breast Imaging Reporting and Data System atlas both on two-view mammograms and CBBCT images. Assessments were repeated by three radiologists with different experience more than 1 month after the initial evaluation. The inter- and intrareader agreements were compared by using the Cohen's weighted Kappa statistic and intraclass correlation coefficient. Weighted Kappa statistic was also used to analyze the agreement between CBBCT images and mammograms. The influence of radiologist experience for breast density assessment was analyzed using a chi-square test.ResultsFor CBBCT images, the inter-reader agreement was 0.781, whereas the agreement on mammograms was 0.744, both demonstrating moderate agreement. The level of intrareader reliability was higher on the CBBCT images than mammograms for breast density evaluation, 0.856 versus 0.786. Based on the majority report, the agreement between these two modalities was on substantial agreement degree. There was a statistically significant difference among radiologists with different levels of experience, and higher density categories were reported more often by experienced reader.ConclusionCBBCT showed equal aptitude and better agreement for the breast density evaluation compared to mammography. CBBCT could be an effective modality for breast density assessment and breast cancer risk evaluation in routine diagnosis and breast cancer screening.
       
  • Evaluation of Simulated Lesions as Surrogates to Clinical Lesions for
           Thoracic CT Volumetry: The Results of an International Challenge
    • Abstract: Publication date: Available online 12 September 2018Source: Academic RadiologyAuthor(s): Marthony Robins, Jayashree Kalpathy-Cramer, Nancy A. Obuchowski, Andrew Buckler, Maria Athelogou, Rudresh Jarecha, Nicholas Petrick, Aria Pezeshk, Berkman Sahiner, Ehsan SameiRationale and ObjectivesTo evaluate a new approach to establish compliance of segmentation tools with the computed tomography volumetry profile of the Quantitative Imaging Biomarker Alliance (QIBA); and determine the statistical exchangeability between real and simulated lesions through an international challenge.Materials and MethodsThe study used an anthropomorphic phantom with 16 embedded physical lesions and 30 patient cases from the Reference Image Database to Evaluate Therapy Response with pathologically confirmed malignancies. Hybrid datasets were generated by virtually inserting simulated lesions corresponding to physical lesions into the phantom datasets using one projection-domain-based method (Method 1), two image-domain insertion methods (Methods 2 and 3), and simulated lesions corresponding to real lesions into the Reference Image Database to Evaluate Therapy Response dataset (using Method 2). The volumes of the real and simulated lesions were compared based on bias (measured mean volume differences between physical and virtually inserted lesions in phantoms as quantified by segmentation algorithms), repeatability, reproducibility, equivalence (phantom phase), and overall QIBA compliance (phantom and clinical phase).ResultsFor phantom phase, three of eight groups were fully QIBA compliant, and one was marginally compliant. For compliant groups, the estimated biases were −1.8 ± 1.4%, −2.5 ± 1.1%, −3 ± 1%, −1.8 ± 1.5% (±95% confidence interval). No virtual insertion method showed statistical equivalence to physical insertion in bias equivalence testing using Schuirmann's two one-sided test (±5% equivalence margin). Differences in repeatability and reproducibility across physical and simulated lesions were largely comparable (0.1%–16% and 7%–18% differences, respectively). For clinical phase, 7 of 16 groups were QIBA compliant.ConclusionHybrid datasets yielded conclusions similar to real computed tomography datasets where phantom QIBA compliant was also compliant for hybrid datasets. Some groups deemed compliant for simulated methods, not for physical lesion measurements. The magnitude of this difference was small (
       
  • Imaging Features of the Whole Uterus Volume CT Perfusion and Influence
           Factors of Blood Supply: A Primary Study in Patients with Cervical
           Squamous Carcinoma
    • Abstract: Publication date: Available online 8 September 2018Source: Academic RadiologyAuthor(s): Dong Yue, Dong Rui Tong, Wang Fei Fei, Zhang Xiao Miao, Pang Hui Ting, Yu Tao, Luo Ya HongRationale and ObjectivesTo explore the imaging features of whole uterus volume CT perfusion (vCTP) and the influence factors of blood supply in cervical squamous carcinoma (CSC).Materials and MethodsvCTP was performed on a 640-slice computed tomography system in 43 patients with CSC diagnosed by biopsy, and 24 cases of them underwent magnetic resonance imaging. The size of the tumor was measured on vCTP and magnetic resonance (MR) images. Perfusion parameters, including arterial blood flow (AF), blood volume, and permeability surface (PS), were measured by two radiologists, using interclass correlation coefficient to evaluate the interobserver reliability. The difference of tumor size and perfusion data was analyzed by paired t test and rank sum test. The correlation of perfusion parameters with some factors was analyzed by Pearson or Spearman correlation analysis.ResultsTumor sizes were not significantly different between vCTP and MR images. The interclass correlation coefficient of each parameter was 0.818–0.945. The AF value of CSC was significantly higher than normal uterine body, and the blood volume and PS values of CSC were not statistically different compared with those of normal uterine body. There was no significant difference in AF value of CSC among different FIGO stages and pathological grades. The AF and PS values of CSC were negatively correlated with the age of the patients.ConclusionThe vCTP could accurately shows the size of the CSC with use of MR as the reference standard, and its perfusion parameters have good measurement stability; the CSC was hypervascular, but this trend was less pronounced in older women.
       
  • Radiology Education in Medical School and Residency: The Views and Needs
           of Program Directors
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Patrick T. Schiller, Andrew W. Phillips, Christopher M. StrausRationale and ObjectivesThe authors of this study used the perspectives of residency program directors (PDs) nationally to explore whether trainees are adequately prepared to utilize and interpret medical imaging as interns, to identify the types of imaging skills most important for residency, and to begin to address current shortcomings in radiology education.Materials and MethodsThe authors created a survey using a modified version of Accreditation Council for Graduate Medical Education radiology milestones and sent it to 100 randomly selected PDs each in pediatrics, internal medicine, obstetrics and gynecology, and general surgery. The survey asked PDs to assess the actual and desired imaging skills of their incoming interns, the incoming interns' variability of skill level upon matriculation, and which imaging skills were most important from the PDs' perspective.ResultsPDs from all specialties identified a significant shortcoming relative to their expectations for both image interpretation and utilization skills. Additionally, PDs identified a significant variability in imaging skills, and described that variability as a hindrance to their programs. All of the potential imaging skills were rated as highly important with little clinically relevant difference between them.DiscussionThis multidisciplinary national survey found a deficiency in imaging education among interns across specialties and substantiates calls for formalized and improved radiology education in undergraduate medical education. Additionally, PDs had difficulty distinguishing which skills were most important, suggesting an unclear understanding of imaging ability needs for interns in respective specialties. More specific needs assessments are warranted on a national level.
       
  • The Problems with the Kappa Statistic as a Metric of Interobserver
           Agreement on Lesion Detection Using a Third-reader Approach When Locations
           Are Not Prespecified
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Joanna H. Shih, Matthew D. Greer, Baris TurkbeyRationale and ObjectivesTo point out the problems with Cohen kappa statistic and to explore alternative metrics to determine interobserver agreement on lesion detection when locations are not prespecified.Materials and MethodsUse of kappa and two alternative methods, namely index of specific agreement (ISA) and modified kappa, for measuring interobserver agreement on the location of detected lesions are presented. These indices of agreement are illustrated by application to a retrospective multireader study in which nine readers detected and scored prostate cancer lesions in 163 consecutive patients (n = 110 cases, n = 53 controls) using the guideline of Prostate Imaging Reporting and Data System version 2 on multiparametric magnetic resonance imaging.ResultsThe proposed modified kappa, which properly corrects for the amount of agreement by chance, is shown to be approximately equivalent to the ISA. In the prostate cancer data, average kappa, modified kappa, and ISA equaled 30%, 55%, and 57%, respectively, for all lesions and 20%, 87%, and 87%, respectively, for index lesions.ConclusionsThe application of kappa could result in a substantial downward bias in reader agreement on lesion detection when locations are not prespecified. ISA is recommended for assessment of reader agreement on lesion detection.
       
  • Prevalence and Reporting Rates of Incidental Dental Disease on Head CT
           Examinations
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Khaled Hammoud, Michael Lanfranchi, Daniel Adams, Harprit S. Bedi, William A. MehanRationale and ObjectivesRoutine head computed tomography (CT) examinations often inadvertently include dental pathology which is often overlooked. The purpose of this study is to examine the prevalence of dental disease incidentally present and detected on head CT examinations, and to determine the effect of the institution of a dental disease field or macro in a standardized head CT dictation template on the rate of reporting dental disease.Materials and MethodsHead CT examinations were retrospectively and randomly selected from all examinations performed 6 months before, and 6 months after the institution of a dental disease field in a standardized head CT template. Dental findings were recorded from the initial finalized report. Examination images were subsequently reviewed for the presence of dental disease by two neuroradiologists who were blinded to the original reports and to each other's findings.ResultsOne hundred examinations were reviewed in the analysis. At our institution, 33% of the randomly selected head CT examinations included the level of the teeth (100/307). Dental disease was determined to be present in 40%–41% of these cases. Only 11% of the initial reports mentioned dental disease (P 
       
  • Investigation of fMRI Analysis Method to Visualize the Difference in the
           Brain Activation Timing
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Sumito Maruyama, Kenzo Muroi, Yoshiyuki HosokaiRationale and ObjectivesIn general functional magnetic resonance imaging (fMRI) analysis, the task onset time of the statistical model is typically set according to the timing of stimulation. In this study, using a high temporal resolution fMRI data, we examined the way of dynamically visualizing the difference in the activation timing between the brain activation areas by analyzing the task onset time of the statistical model shifted from the actual stimulation timing.Materials and MethodsfMRI data with high temporal resolution was acquired using 3 T magnetic resonance imaging for 10 right-handed healthy volunteers. While being scanned, the volunteers completed a task that comprised two sets of a rest and right hand grip movement task. Statistical Parametric Mapping 12 (SPM12) software was used to analyze fMRI data. After preprocessing, statistical analyses were performed by shifting the task onset time on the statistical model by about 1 second forward or backward from the actual stimulation timing. Activation maps of multiple time phases were then created.ResultsActivity was observed to the left of the primary motor area and the supplementary motor area and to the right of the cerebellum (familywise error rate, P 
       
  • Impact of a New Adaptive Statistical Iterative Reconstruction (ASIR)-V
           Algorithm on Image Quality in Coronary Computed Tomography Angiography
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Gianluca Pontone, Giuseppe Muscogiuri, Daniele Andreini, Andrea I. Guaricci, Marco Guglielmo, Andrea Baggiano, Fabio Fazzari, Saima Mushtaq, Edoardo Conte, Andrea Annoni, Alberto Formenti, Elisabetta Mancini, Massimo Verdecchia, Alessandro Campari, Chiara Martini, Marco Gatti, Laura Fusini, Lorenzo Bonfanti, Elisa Consiglio, Mark G. RabbatRationale and objectivesA new postprocessing algorithm named adaptive statistical iterative reconstruction (ASIR)-V has been recently introduced. The aim of this article was to analyze the impact of ASIR-V algorithm on signal, noise, and image quality of coronary computed tomography angiography.Materials and MethodsFifty consecutive patients underwent clinically indicated coronary computed tomography angiography (Revolution CT; GE Healthcare, Milwaukee, WI). Images were reconstructed using filtered back projection and ASIR-V 0%, and a combination of filtered back projection and ASIR-V 20%–80% and ASIR-V 100%. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for left main coronary artery (LM), left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA) and were compared between the different postprocessing algorithms used. Similarly a four-point Likert image quality score of coronary segments was graded for each dataset and compared. A cutoff value of P 
       
  • Radiation Dose Reduction at Low Tube Voltage CCTA Based on the CNR Index
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Takanori Masuda, Yoshinori Funama, Takeshi Nakaura, Tomoyasu Satou, Tomokazu Okimoto, Yukari Yamashita, Naoyuki Imada, Kazuo AwaiRationale and ObjectivesWe compared the radiation dose and diagnostic accuracy on 120- and 100-kVp coronary computed tomography angiography (CCTA) scans whose contrast-to-noise ratio (CNR) was the same.Materials and MethodsWe studied 1311 coronary artery segments from 100 patients. For 120-kVp scans, the targeted image level was set at 25 Hounsfield units (HU). For 100-kVp scans, the targeted noise level was set at 30 HU to obtain the same CNR as at 120 kVp. We compared the CNR and the radiation dose on scans acquired at 120 and 100 kVp. Invasive coronary angiography (ICA) images were evaluated by an interventional coronary angiography specialist, and CCTA images were evaluated by a radiologist. Coronary artery disease was defined as a luminal narrowing ≧50% for ICA and CCTA. With ICA considered the gold standard, the diagnostic accuracy (sensitivity, specificity, positive predictive value, and negative predictive value) was analyzed on both 120- and 100-kVp CCTA images. We also compared the diagnostic accuracy for area under the receiver operating characteristic curve of the ICA and CCTA performed at 120 and 100 kVp. Two blinded observers visually evaluated the septal branch.ResultsThe mean dose-length product was 48% lower at 100 kVp than at 120 kVp (P 
       
  • Advanced Modeled Iterative Reconstruction (ADMIRE) Facilitates Radiation
           Dose Reduction in Abdominal CT
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Stephan Ellmann, Ferdinand Kammerer, Thomas Allmendinger, Matthias Hammon, Rolf Janka, Michael Lell, Michael Uder, Manuel KramerRationale and ObjectivesThis study aimed to determine the potential degree of radiation dose reduction achievable using Advanced Modeled Iterative Reconstruction (ADMIRE) in abdominal computed tomography (CT) while maintaining image quality. Moreover, this study compared differences in image noise reduction of this iterative algorithm with radiation dose reduction.MethodsEleven consecutive patients scheduled for abdominal CT were scanned according to our institute's standard protocol (100 kV, 289 reference mAs). Using a proprietary reconstruction software, CT images of these patients were reconstructed as either full-dose weighted filtered back projections or with simulated radiation dose reductions down to 10% of the full-dose level and ADMIRE at either strength 3 or strength 5. Images were marked with arrows pointing on anatomic structures of the abdomen, differing in their contrast to the surrounding tissue. Structures were grouped into high-, medium-, and low-contrast subgroups. In addition, the intrinsic noise of these structures was measured. That followed, image pairs were presented to observers, with five readers assessing image quality using two-alternative-forced-choice comparisons. In total, 3000 comparisons were performed that way.ResultsBoth ADMIRE 3 and 5 decreased noise of the anatomic structures significantly compared to the filtered back projection, with an additional significant difference between ADMIRE 3 and 5. Radiation dose reduction potential for ADMIRE ranged from 29.0% to 53.5%, with no significant differences between ADMIRE 3 and 5 within the contrast subgroups.The potential levels of radiation dose reduction for ADMIRE 3 differed significantly between high-, medium-, and low-contrast structures, whereas for ADMIRE 5, there was only a significant difference between the high- and the medium-contrast subgroups.ConclusionAlthough ADMIRE 5 permits significantly higher noise reduction potential than ADMIRE 3, it does not facilitate higher levels of radiation dose reduction. ADMIRE nonetheless holds remarkable potential for radiation dose reduction, which features a certain dependency on the contrast of the structure of interest. Applying ADMIRE with a strength of 3 in abdominal CT may permit radiation dose reduction of about 30%.
       
  • Characterization of Urinary Stone Composition by Use of Whole-body,
           Photon-counting Detector CT
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Andrea Ferrero, Ralf Gutjahr, Ahmed F. Halaweish, Shuai Leng, Cynthia H. McColloughRational and ObjectivesThis study aims to investigate the performance of a whole-body, photon-counting detector (PCD) computed tomography (CT) system in differentiating urinary stone composition.Materials and MethodsEighty-seven human urinary stones with pure mineral composition were placed in four anthropomorphic water phantoms (35–50 cm lateral dimension) and scanned on a PCD-CT system at 100, 120, and 140 kV. For each phantom size, tube current was selected to match CTDIvol (volume CT dose index) to our clinical practice. Energy thresholds at [25, 65], [25, 70], and [25, 75] keV for 100, 120, and 140 kV, respectively, were used to generate dual-energy images. Each stone was automatically segmented using in-house software; CT number ratios were calculated and used to differentiate stone types in a receiver operating characteristic (ROC) analysis. A comparison with second- and third-generation dual-source, dual-energy CT scanners with conventional energy integrating detectors (EIDs) was performed under matching conditions.ResultsFor all investigated settings and smaller phantoms, perfect separation between uric acid and non–uric acid stones was achieved (area under the ROC curve [AUC] = 1). For smaller phantoms, performance in differentiation of calcium oxalate and apatite stones was also similar between the three scanners: for the 35-cm phantom size, AUC values of 0.76, 0.79, and 0.80 were recorded for the second- and third-generation EID-CT and for the PCD-CT, respectively. For larger phantoms, PCD-CT and the third-generation EID-CT outperformed the second-generation EID-CT for both differentiation tasks: for a 50-cm phantom size and a uric acid/non–uric acid differentiating task, AUC values of 0.63, 0.95, and 0.99 were recorded for the second- and third-generation EID-CT and for the PCD-CT, respectively.ConclusionPCD-CT provides comparable performance to state-of-the-art EID-CT in differentiating urinary stone composition.
       
  • Magnetic Resonance Imaging Parameters in Predicting the Treatment Outcome
           of High-intensity Focused Ultrasound Ablation of Uterine Fibroids With an
           Immediate Nonperfused Volume Ratio of at Least 90%
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Bilgin Keserci, Nguyen Minh DucRationale and ObjectivesWe aimed to investigate the role of magnetic resonance imaging parameters in predicting the treatment outcome of high-intensity focused ultrasound (HIFU) ablation of uterine fibroids with a nonperfused volume (NPV) ratio of at least 90%.Material and MethodsA total of 120 women who underwent HIFU treatment were divided into groups 1 (n = 72) and 2 (n = 48), comprising patients with an NPV ratio of at least 90% and less than 90%, respectively. Multivariate logistic regression analyses were carried out to investigate the potential predictors of the NPV ratio of at least 90%. The NPV ratios immediately post-treatment, therapeutic efficacy at 6 months' follow-up, and safety in terms of adverse effects and changes in anti-Mullerian hormone level were assessed.ResultsBy introducing multiple predictors obtained from multivariate analyses into a generalized estimating equation model, the results showed that the thickness of the subcutaneous fat layer in the anterior abdominal wall, peak enhancement of fibroid, time to peak of fibroid, and the ratio of area under the curve of fibroid to myometrium were statistically significant, except T2 signal intensity ratio of fibroid to myometrium, hence predicting an NPV ratio of at least 90%. No serious adverse effects and no significant difference between the anti-Mullerian hormone levels before or 6 months post-treatment were reported.ConclusionsThe findings in this study suggest that the achievement of NPV ratio of at least 90% in magnetic resonance imaging-guided HIFU treatment of uterine fibroids based on prediction model appears clinically possible without compromising the safety of patients.
       
  • The Value of Supine Chest X-Ray in the Diagnosis of Pneumonia in the Basal
           Lung Zones
    • Abstract: Publication date: October 2018Source: Academic Radiology, Volume 25, Issue 10Author(s): Wolfgang G. Kunz, Maximilian Patzig, Alexander Crispin, Robert Stahl, Maximilian F. Reiser, Mike NotohamiprodjoRationale and ObjectivesBasal lung opacities are frequently observed on supine chest x-ray (SCXR) of intensive care patients, causing insecurity among clinicians and radiologists. We sought to determine the diagnostic accuracy of SCXR for basal pneumonia.Materials and MethodsWe identified 172 patients who received both SCXR and computed tomography within 1 hour. Two readers examined the SCXR and rated findings in both basal zones according to the following scale: 0 = “no pneumonia,” 1 = “possible pneumonia,” 2 = “highly suspected pneumonia.” Computed tomography served as standard of reference. Sensitivity, specificity, and positive and negative predictive values (PPV/NPV) were calculated once pooling 0 and 1 as negative and once pooling 1 and 2 as positive finding.ResultsWhen pooling 0 and 1 as negative, sensitivity was 0.45 (right)/0.38 (left), specificity was 0.94/0.97, PPV was 0.76/0.79, and NPV was 0.81/0.84. When pooling 1 and 2 as positive, sensitivity was 0.80/0.75, specificity was 0.62/0.58, PPV was 0.45/0.35, and NPV was 0.88/0.89. The most common findings in false-positive cases were combined pleural effusions and lower lobe atelectasis.ConclusionsInterpreting only highly suspicious basal opacities as pneumonia considerably increases the PPV with almost constant NPV. Clinicians and radiologists should be aware of the limitations of SCXR regarding basal pneumonia.
       
  • Establishing a Surgical Preliminary Year in the IR Residency: Keys to
           Success
    • Abstract: Publication date: Available online 6 September 2018Source: Academic RadiologyAuthor(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.
       
  • Convolutional Neural Networks with Template-Based Data Augmentation for
           Functional Lung Image Quantification
    • Abstract: Publication date: Available online 6 September 2018Source: Academic RadiologyAuthor(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
       
  • Combination of Adaptive Statistical Iterative Reconstruction-V and Lower
           Tube Voltage During Craniocervical Computed Tomographic Angiography Yields
           Better Image Quality with a Reduced Radiation Dose
    • Abstract: Publication date: Available online 5 September 2018Source: Academic RadiologyAuthor(s): Chih-Wei Chen, Po-An Chen, Chiung-Chen Chou, Jui-Hsun Fu, Po-Chin Wang, Shuo-Hsiu Hsu, Ping-Hong LaiRationale and ObjectivesTo evaluate image quality and radiation exposure when using the adaptive statistical iterative reconstruction-V (ASIR-V) algorithm for reconstructing craniocervical computed tomographic angiography images acquired at 100 kVp.Materials and MethodsWe randomly divided 121 patients into three groups: group A (conventional protocol), 120 kVp with filtered back projection; group B, 120 kVp with 50% ASIR-V; and group C, 100 kVp with 50% ASIR-V. All patients underwent scans in a 256-slice computed tomography (CT) scanner. Radiation dose (volume CT dose index), dose-length product, and effective dose, objective parameters such as arterial attenuation value, signal-to-noise ratio, contrast-to-noise ratio, and noise obtained at head, neck, and shoulder levels were compared among the groups. Subjective image quality was independently assessed by two radiologists, and interobserver reliability was assessed using kappa analysis.ResultsThe radiation dose in group C was the lowest (p < 0.01) with a 40% reduction in volume CT dose index, dose-length product, and effective dose values compared to group A, and group C showed higher arterial attenuation than either group A or B (p < 0.01). Additionally, signal-to-noise ratio and contrast-to-noise ratio were higher and noise was lower in groups B and C than group A. Group C had better subjective image quality than groups A and B (p < 0.05), and the interobserver reliability between the two radiologists was high (k = 0.783).ConclusionCompared to the conventional protocol, using 50% ASIR-V and the 100 kVp protocol during craniocervical computed tomographic angiography yields better objective and subjective image quality at lower radiation doses.
       
  • Two-dimensional Texture Analysis Based on CT Images to Differentiate
           Pancreatic Lymphoma and Pancreatic Adenocarcinoma: A Preliminary Study
    • Abstract: Publication date: Available online 5 September 2018Source: Academic RadiologyAuthor(s): Zixing Huang, Mou Li, Du He, Yi Wei, Haopeng Yu, Yi Wang, Fang Yuan, Bin SongObjectiveTo retrospectively assess the diagnostic performance of texture analysis and characteristics of CT images for the discrimination of pancreatic lymphoma (PL) from pancreatic adenocarcinoma (PA).MethodsFifteen patients with pathologically proved PL were compared with 30 age-matched controls with PA in a 1:2 ratio. Patients underwent a CT scan with three phases including the precontrast phase, the arterial phase, and the portal vein phase. The regions of interest of PA and PL were drawn and analyzed to derive texture parameters with MaZda software. Texture features and CT characteristics were selected for the discrimination of PA and PL by the least absolute shrinkage and selection operator and logistic regression analysis. Receiver operating characteristic analysis was performed to assess the diagnostic performance of texture analysis and characteristics of CT images.ResultsSixty texture features were obtained by MaZda. Of these, four texture features were selected by least absolute shrinkage and selection operator. Following this, three texture features and nine CT characteristics were excluded by logistic regression analysis. Finally, “S(5, −5)SumAverg” (texture feature) and “Size” (CT characteristic) were selected for the receiver operating characteristic analysis. The AUC of “S(5, −5)SumAverg” and “Size” were to be 0.704 and 0.821, respectively, with no significance between them (p = 0.3064).ConclusionTwo-dimensional texture analysis is a quantitative method for differential diagnosis of PL from PA. The diagnostic performance of both texture analysis and CT characteristics was similar.
       
  • How Evolutionary Theory Illuminates Radiologic Practice: Bipedalism
    • Abstract: Publication date: Available online 3 September 2018Source: Academic RadiologyAuthor(s): Richard B. Gunderman, Abdul R.S. Aasar
       
  • Perception's Crucial Role in Radiology Education
    • Abstract: Publication date: Available online 3 September 2018Source: Academic RadiologyAuthor(s): Richard B. Gunderman, Parth Patel
       
  • Effect of Dual-Source Radiofrequency Transmission on Left Ventricular
           Measurements and Measurement Reproducibility at 3.0 T Cardiac MR Imaging:
           Comparison with Conventional Single-Source Transmission Reference
    • Abstract: Publication date: Available online 30 August 2018Source: Academic RadiologyAuthor(s): Chunhai Li, Bo Liu, Hong Meng, Guangbin Wang, Cuiyan Wang, Haipeng JiaRationale and ObjectivesTo prospectively assess effect of dual-source radiofrequency (RF) transmission on left ventricular (LV) measurements and measurements reproducibility at 3.0 T MR using balanced steady-state free precession (b-SSFP) cine imaging, compared to the conventional single-source RF transmission reference approach.Materials and MethodsCardiac b-SSFP cine imaging was performed in 19 subjects at 3.0 T MR equipped with dual-source RF transmission. All images were analyzed to obtain LV end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, mass, LV end-diastolic inferior wall thickness, and interventricular septal thickness. The difference of all LV measurements between the two imaging techniques was tested with the paired t test and the intertechnique agreement was tested through linear regression and Bland-Altman analyses. Additionally, repeated LV measurements were performed to determine intra and interobserver variability with the Bland-Altman method, the 95% limits of agreement, the coefficient of variation (CV) and the intraclass correlation coefficient.ResultsCompared to conventional single-source, dual-source slightly overestimated end-diastolic volume, end-systolic volume, and stroke volume (mean differences, 3.9 mL ± 9.7, 1.1 mL ± 2.6, and 2.8 mL ± 9.1, respectively; p> 0.05), resulting in a small but significant positive bias in ejection fraction (1.5% ± 2.6; p = 0.021). Mass was significantly smaller with dual-source than with single-source (−4.0 g ± 6.5, p = 0.001). Dual-source slightly underestimated interventricular septal thickness (−0.29 mm ± 0.6, p = 0.067) and significantly underestimated LV end-diastolic inferior wall thickness (−0.55 mm ± 0.4, p < 0.0001). The two techniques in measurements correlated highly (r2 = 0.81 to 0.96, p < 0.0001). Intra and interobserver variability in dual-source measurements was much lower than that in single-source, and variability values were
       
  • Contrast-to-Noise Ratio Optimization in Coronary Computed Tomography
           Angiography: Validation in a Swine Model
    • Abstract: Publication date: Available online 30 August 2018Source: Academic RadiologyAuthor(s): Logan Hubbard, Shant Malkasian, Yixiao Zhao, Pablo Abbona, Sabee MolloiRationale and ObjectivesThe accuracy of coronary computed tomography (CT) angiography depends upon the degree of coronary enhancement as compared to the background noise. Unfortunately, coronary contrast-to-noise ratio (CNR) optimization is difficult on a patient-specific basis. Hence, the objective of this study was to validate a new combined diluted test bolus and CT angiography protocol for improved coronary enhancement and CNR.Materials and MethodsThe combined diluted test bolus and CT angiography protocol was validated in six swine (28.9 ± 2.7 kg). Specifically, the aortic and coronary enhancement and CNR of a standard CT angiography protocol, and a new combined diluted test bolus and CT angiography protocol were compared to a reference retrospective CT angiography protocol. Comparisons for all data were made using box plots, t tests, regression, Bland–Altman, root-mean-square error and deviation, as well as Lin's concordance correlation.ResultsThe combined diluted test bolus and CT angiography protocol was found to improve aortic and coronary enhancement by 26% and 13%, respectively, as compared to the standard CT angiography protocol. More importantly, the combined protocol was found to improve aortic and coronary CNR by 29% and 20%, respectively, as compared to the standard protocol.ConclusionA new combined diluted test bolus and CT angiography protocol was shown to improve coronary enhancement and CNR as compared to an existing standard CT angiography protocol.
       
  • Toward Improving Breast Cancer Imaging: Radiological Assessment of
           Propagation-Based Phase-Contrast CT Technology
    • Abstract: Publication date: Available online 25 August 2018Source: Academic RadiologyAuthor(s): Seyedamir Tavakoli Taba, Patrycja Baran, Sarah Lewis, Robert Heard, Serena Pacile, Yakov I. Nesterets, Sherry C. Mayo, Christian Dullin, Diego Dreossi, Fulvia Arfelli, Darren Thompson, Mikkaela McCormack, Maram Alakhras, Francesco Brun, Maurizio Pinamonti, Carolyn Nickson, Chris Hall, Fabrizio Zanconati, Darren Lockie, Harry M QuineyRationale and ObjectivesThis study employs clinical/radiological evaluation in establishing the optimum imaging conditions for breast cancer imaging using the X-ray propagation-based phase-contrast tomography.Materials and MethodsTwo series of experiments were conducted and in total 161 synchrotron-based computed tomography (CT) reconstructions of one breast mastectomy specimen were produced at different imaging conditions. Imaging factors include sample-to-detector distance, X-ray energy, CT reconstruction method, phase retrieval algorithm applied to the CT projection images and maximum intensity projection. Observers including breast radiologists and medical imaging experts compared the quality of the reconstructed images with reference images approximating the conventional (absorption) CT. Various radiological image quality attributes in a visual grading analysis design were used for the radiological assessments.ResultsThe results show that the application of the longest achievable sample-to-detector distance (9.31 m), the lowest employed X-ray energy (32 keV), the full phase retrieval, and the maximum intensity projection can significantly improve the radiological quality of the image. Several combinations of imaging variables resulted in images with very high-quality scores.ConclusionThe results of the present study will support future experimental and clinical attempts to further optimize this innovative approach to breast cancer imaging.
       
  • Accuracy of Breast Magnetic Resonance Imaging Compared to Mammography in
           the Preoperative Detection and Measurement of Pure Ductal Carcinoma In
           Situ: A Retrospective Analysis
    • Abstract: Publication date: Available online 24 August 2018Source: Academic RadiologyAuthor(s): Heike Preibsch, Johannes Beckmann, Johannes Pawlowski, Christopher Kloth, Markus Hahn, Annette Staebler, Beate M. Wietek, Konstantin Nikolaou, Benjamin WiesingerRationale and ObjectivesDuctal carcinoma in situ (DCIS) hinders imaging detection due to multifocal appearance and discontinuous growth. Preoperative determination of its extent is therefore challenging.Aim of this study was to investigate the additional benefit of breast magnetic resonance imaging (MRI) to mammography (MG) in the diagnosis of DCIS according to size and grading.Materials and MethodsRetrospective analysis of 295 patients with biopsy-proven, pure DCIS. Mean patient age was 57.0 years (27–87 years). All patients obtained MG. Additional MRI was performed in 41.7% (123/295). Mammographic breast density, background parenchymal enhancement (BPE), tumor size and grading were analysed. Tumor size on MG and MRI were compared to histopathological size of the surgical specimen.ResultsMean tumor size was 39.6 mm. DCIS was occult on MG in 24.4% (30/123) and on MRI in 1.6% (2/123). Size was underestimated by 4.6 mm (mean) mammographically. DCIS was high grade in 54.5% (67/123), intermediate grade in 40.7% (50/123) and low grade in 4.9% (6/123). MG was exact regarding tumor size in low grade DCIS, underestimated intermediate grade DCIS by 1 mm (median) and high grade DCIS by 10.5 mm. MRI overestimated low grade DCIS by 1 mm (median), was exact regarding intermediate grade DCIS and underestimated high grade DCIS by 1 mm. BPE did not influence tumor detection and measurement.ConclusionMRI outperforms MG in the detection and size estimation of DCIS and can reduce positive margin rates.
       
  • MRI Findings After Cryoablation of Primary Breast Cancer Without Surgical
           Resection
    • Abstract: Publication date: Available online 24 August 2018Source: Academic RadiologyAuthor(s): Youichi Machida, Akiko Shimauchi, Takao Igarashi, Eisuke FukumaRationale and ObjectivesTo retrospectively evaluate findings on serial magnetic resonance imaging (MRI) after cryoablation for breast cancer lesions without subsequent surgical resection.Materials and MethodsThis study was approved by the Institutional Review Board and the requirement to obtain informed consent waived. Ductal carcinoma in situ or invasive carcinoma ≤15 mm, nuclear grade 1 or 2, estrogen receptor positive/human epidermal growth factor 2 negative without lymph node metastasis were treated with cryoablation without subsequent excision. Two observers independently reviewed the first two postcryoablation MRIs for shape (none, focus-to-mass, or nonmass enhancement) and suspicion of residual disease (positive or negative). Fisher's exact or the Mann–Whitney U test was used to assess significance. Interobserver agreement on findings was evaluated by calculating κ values.ResultsFifty-four patients were enrolled. The first and second postcryoablation MRIs were performed 22–171 days and 82–487 days after cryoablation, respectively. Interobserver agreement ranged from fair to moderate (κ = 0.356–0.434). Observer 1 or 2 identified suspicious areas on the first postcryoablation MRI in seven cases (13.0%). These were significantly associated with focus-to-mass shape (vs non–focus-to-mass: nonmass enhancement or none) and residual disease or recurrence suspected by both observers (p < 0.001). There were no cases of both observers identifying suspicious findings on the second postcryoablation MRI.ConclusionSuspicious findings can be detected within the treated area at the first postcryoablation MRI. These can resolve during subsequent adjuvant therapies and follow-up.
       
  • Morphological and Semiquantitative Kinetic Analysis on Dynamic Contrast
           Enhanced MRI in Triple Negative Breast Cancer Patients
    • Abstract: Publication date: Available online 23 August 2018Source: Academic RadiologyAuthor(s): Silvia Gigli, Maria Ida Amabile, Emanuele David, Alessandro De Luca, Cristina Grippo, Lucia Manganaro, Massimo Monti, Laura BallesioRationale and ObjectivesThe aim of this study was to retrospectly investigate the association between different breast cancer (BC) immunohistochemical subtypes and morphological and semiquantitative kinetic analysis on breast magnetic resonance imaging (MRI) performed before surgery treatment. Specifically we aimed to assess MRI features of triple-negative breast cancer (TNBC) compared to the other BC subtypes (nTNBC).Materials and MethodsPatients undergone to breast MRI and then diagnosed with BC by core-needle biopsy were included. The MRI morphological and kinetic features were studied. Parametric and non-parametric tests were used, as appropriate.ResultsSeventy-five BC patients were considered, 30 patients included in TNBC Group and 45 patients included in nTNBC Group. We found in TNBC Group a greater mean lesion size (P
       
  • Body Weight-Based Protocols During Whole Body FDG PET/CT Significantly
           Reduces Radiation Dose without Compromising Image Quality:Findings in a
           Large Cohort Study
    • Abstract: Publication date: Available online 23 August 2018Source: Academic RadiologyAuthor(s): Charbel Saade, Ahmad Ammous, Alain S. Abi-Ghanem, Frederik Giesel, Karl AsmarRationale and ObjectivesTo investigate radiation dose reduction during whole body fluorodeoxyglucose (18F-FDG) positron emission tomographic (PET)/computed tomography (CT) by employing weight-based protocols.Materials and MethodsOne thousand and twenty-eight patients were referred for 18F-FDG PET/CT study with one of two protocols: conventional protocol I; 120 kVp, 120 mAs, 0.5 second rotation time, pitch 0.8 mm/rot across all body weights; four-tier body weight protocol II all used 140 kVp, 0.75 seconds rotation time and pitch 0.8 mm/rot: Protocol A (≤60 kg): 35 mAs, Protocol B (61–80 kg): 50 mAs, Protocol C (81–100 kg): 65 mAs, and Protocol D: (>101 kg): 100 mAs. All protocols employed tube current modulation. Quantitative and qualitative image visual grading characteristics assessed image quality.ResultsPatient demographics demonstrated no significant difference between each protocol except for patient weight in weight protocol IIB (p < 0.009). Mean effective dose in all protocols were significantly lower in Protocol B compared to A (p < 0.009). Contrast-to-noise ratio demonstrated no differences between each protocol (p < 0.21) except for weight protocol in protocol IIA (
       
  • Noninvasive Differential Diagnosis of Liver Iron Contents in Nonalcoholic
           Steatohepatitis and Simple Steatosis Using Multiecho Dixon Magnetic
           Resonance Imaging
    • Abstract: Publication date: Available online 22 August 2018Source: Academic RadiologyAuthor(s): Tae-Hoon Kim, Chang-Won Jeong, Hong Young Jun, Youe Ree Kim, Ju Young Kim, Young Hwan Lee, Kwon-Ha YoonRationale and ObjectivesThe roles of iron stores in nonalcoholic fatty liver disease have not yet been clearly identified, and it is lack of uniform criteria and a standardized study design for assessing the liver iron content (LIC) in nonalcoholic steatohepatitis (NASH). This study was to compare LICs in biopsy-proven simple steatosis (SS) and NASH based on T2⁎-relaxometry.Material and MethodsA total of 32 subjects divided to three groups, consisting of 10 healthy controls, 12 SS and 10 NASH. All MRI examinations were performed on a 3 T MRI with a 32-channel body coil. To measure T2⁎-value, we used a gradient echo sequence with six multiechoes within a single breath-hold. Hepatic iron contents among three groups were compared using Kruskal–Wallis H test and Mann–Whitney's posthoc tests. Diagnostic accuracy was determined by calculating the area under the receiver operating characteristics curve. To identify the reliability of iron measurements in the different region of interests, coefficient of variance (CV) was calculated overall CV values for the variability of measurements. Interobserver agreement and reliability were estimated by calculating the intraclass correlation coefficient.ResultsThe variations of all LIC measurements are not exceeded 20%, as a mean CV value 18.3%. intraclass correlation coefficients were higher than 0.9. Mean T2⁎-values at localized region of interests were healthy controls 45.42 ± 7.19 ms, SS 20.96 ± 4.28 ms, and NASH 15.49 ± 2.87 ms. The mean T2⁎-value in NASH is significantly shorter than that in SS (p = 0.008). The area under the receiver operating characteristics curve to distinguish NASH from SS was 0.908 (95% confidence interval 0.775–1.000, p = 0.001) at a cut-off of iron contents greater than 17.95 ms, and its diagnostic accuracy had 0.833 sensitivity and 0.800 specificity.ConclusionThis study demonstrates that the T2⁎ calculation can help to differentially diagnose NASH.
       
  • A Review of Options for Localization of Axillary Lymph Nodes in the
           Treatment of Invasive Breast Cancer
    • Abstract: Publication date: Available online 22 August 2018Source: Academic RadiologyAuthor(s): Ryan W. Woods, Melissa S. Camp, Nicholas J. Durr, Susan C. HarveyInvasive breast cancer is a common disease, and the most common initial site of metastatic disease are the axillary lymph nodes. As the standard of care shifts towards less invasive surgery in the axilla for patients with invasive breast cancer, techniques have been developed for axillary node localization that allow targeted dissection of specific lymph nodes without requiring full axillary lymph node dissection. Many of these techniques have been adapted from technologies developed for localization of lesions within the breast and include marker clip placement with intraoperative ultrasound, carbon-suspension liquids, localization wires, radioactive seeds, magnetic seeds, radar reflectors, and radiofrequency identification devices.The purpose of this article is to summarize these methods and describe benefits and drawbacks of each method for performing localization of lymph nodes in the axilla.
       
  • Reduced Contrast Volume and Radiation Dose During Computed Tomography of
           the Pancreas: Timing-Specific Contrast Media Protocol
    • Abstract: Publication date: Available online 17 August 2018Source: Academic RadiologyAuthor(s): Charbel Saade, Jad Chokr, Lena Naffaa, Walid Faraj, Ali Shamseddine, Deborah Mukherji, Skye El Sayegh, Rita Assi, Ali HaydarRationale and ObjectiveTo investigate the opacification of the pancreatic vasculature and parenchyma during computed tomography utilizing a patient-specific contrast formula.Materials and MethodsThis hybrid prospective and retrospective study was approved by the institution review board. In 220 consecutive patients, pancreatic CT was performed with one of two protocols: protocol A, 100 mL of contrast material injected via timed bolus triggering technique; or protocol B, employing a patient-specific contrast media protocol specifically timed at the gastroduodenal artery; both protocols employed 4.5 mL/s contrast media and 100 mL saline chaser. Attenuation of pancreatic parenchymal, arterial, and venous vasculature supplying the pancreas was measured. Effective dose was calculated. Data were compared to the independent two-sample t test. Receiver operating characteristic, visual grading characteristic, and Cohens’ kappa analyses were performed.ResultsMean pancreatic density measurements in each of the pancreatic segments during the arterial and venous phase were significantly higher in Protocol B (mean ± standard deviation, art: 96.59 HU ± 27.37; venous: 91.28 HU ± 20.88) compared to A (art: 77.86 HU ± 21.14; venous: 73.99 HU ± 14.75) (p < 0.0001). Mean arterial opacification was significantly higher in protocol B compared to A with the abdominal aorta (p < 0.007), superior mesenteric (p < 0.0002), gastroduodenal (proximal segment only p < 0.014), and splenic arteries (p < 0.036). In the venous circulation, the inferior vena cava, superior mesenteric, portal and splenic veins (all segments) demonstrated significant reduction in vascular opacification protocol B compared to A (p < 0.001). The contrast media volume in protocol B (57.60 ± 12.25 mL) was significantly lower than in protocol A (100 ± 1 mL) (p < 0.001). Effective dose was significantly reduced in protocol B (2.75 ± 0.63 mSv) compared to A (4.015 ± 0.89 mSv) (p < 0.001). Receiver operating characteristic and visual grading characteristic analysis demonstrated significantly higher area under the curve for protocol B (p < 0.0001) (p < 0.034) respectively, with inter-reader agreement increasing from good to excellent in pancreatic lesion detection.ConclusionTiming-specific contrast media protocol enhances image quality at reduced contrast volume and radiation dose during computed tomography of the pancreas.
       
  • Tumor Response Criteria—Radiological Implications
    • Abstract: Publication date: Available online 17 August 2018Source: Academic RadiologyAuthor(s): Ashish P. Wasnik
       
  • Long-term Personal Relationships and Well-being
    • Abstract: Publication date: Available online 16 August 2018Source: Academic RadiologyAuthor(s): Richard B. Gunderman, Danielle A. Bly
       
  • Building a Tree From the Leaves Down: A Challenge for Contemporary
           Educators
    • Abstract: Publication date: Available online 16 August 2018Source: Academic RadiologyAuthor(s): Richard B. Gunderman, Kitt Shaffer
       
  • Patient-Reported Breast Density Awareness and Knowledge after Breast
           Density Legislation Passage
    • Abstract: Publication date: Available online 16 August 2018Source: Academic RadiologyAuthor(s): Randy C. Miles, Constance Lehman, Erica Warner, Ashley Tuttle, Mansi SaksenaRationale and ObjectivesTo determine awareness and knowledge of breast density and breast density legislation among women receiving routine mammography following passage of Massachusetts breast density legislation.Materials and MethodsA survey assessing breast density awareness and knowledge was administered to all women receiving screening mammography over two separate 1-week periods at an academic medical center following implementation of mandatory breast density notification. Survey questions queried sociodemographic factors, breast density knowledge, legislation awareness, and medical decision-making intent.ResultsOf 1000 survey recipients, 338 (33.8%) returned their survey. Most women were surprised (207/338; 61.2%) to receive their breast density notification letter and unaware (302/338; 89.9%) of newly implemented breast density legislation. The majority (185/338; 54.7%) of survey respondents self-reported having dense breasts. Only 61.1% (113/185) of women with dense breasts reported that their personal breast density increased breast cancer risk, while only 60.0% (78/130) of women with non dense breasts reported that their personal breast density did not increase breast cancer risk. Significant differences between women with dense and nondense breasts were observed related to intention to follow-up with a health practitioner (118/185; 63.8% vs. 66/130; 50.8%, p = 0.03) and views on necessity of supplemental screening based on personal breast density (83/185; 45.1% vs. 20/130; 15.4%, p < 0.01).ConclusionsDespite implementation of state breast density laws since 2009, confusion and misinformation about breast density persists among women receiving mammography screening. Innovative tools that more effectively inform patients, may be required to improve communication and patient understanding about breast density and subsequent breast care management.
       
  • Supporting Radiology Residents’ Professional Development Through a
           Competitive Intramural Grant
    • Abstract: Publication date: Available online 12 August 2018Source: Academic RadiologyAuthor(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.
       
  • Evaluating Renal Fibrosis with R2* Histogram Analysis of the Whole Cortex
           in a Unilateral Ureteral Obstruction Model
    • Abstract: Publication date: Available online 12 August 2018Source: Academic RadiologyAuthor(s): Tingting Zha, Xiaojun Ren, Zhaoyu Xing, Jinggang Zhang, Xiaojuan Tian, Yanan Du, Wei Xing, Jie ChenRationale and ObjectivesThe aim of this study was to use histogram analysis to assess the correlation between blood oxygen-level dependent magnetic resonance imaging (BOLD-MRI) and renal fibrosis induced by unilateral ureteral obstruction (UUO) in an animal model for a long experimental period.Materials and MethodsThe rabbits were randomly divided into a control group (n = 6) and a UUO group (n = 30). The rabbits in the UUO group underwent left ureteral obstruction surgery. BOLD-MRI examinations were performed at 2, 4, 6, and 8 weeks after ligation. After the examinations, nephrectomy was performed for histologic evaluation. Histogram analysis of the left renal cortex (C) R2* values was performed to measure the mean, median, 10th percentile, 90th percentile, skewness, and kurtosis for all kidneys. Masson trichrome staining was used to assess the percentage of fibrotic area.ResultsThe histogram R2* values of the mean, median, 10th percentile, and 90th percentile at week 2 were all lower than those at baseline. Over the course of UUO progression, there were statistical differences between the histogram R2* values at any other two time points, except between weeks 4 and 6, and weeks 6 and 8. A close correlation was found between the percentage of fibrotic area and R2* values (mean: F = 21.49, p = 0.0001, R2 = 0.49, median: F = 30.07, p < 0.0001, R2 = 0.58, 10th percentile: F = 31.02, p < 0.0001, R2 = 0.59, 90th percentile: F = 24.13, p < 0.0001, R2 = 0.52).ConclusionBOLD-MRI could reflect the formation and progression of renal fibrosis in a rabbit UUO model; however, the value of BOLD-MRI in the long-term evaluation of fibrosis is limited.
       
  • Prediction of Cancer Masking in Screening Mammography Using Density and
           Textural Features
    • Abstract: Publication date: Available online 10 August 2018Source: Academic RadiologyAuthor(s): James G. Mainprize, Olivier Alonzo-Proulx, Taghreed I. Alshafeiy, James T. Patrie, Jennifer A. Harvey, Martin J. YaffeRationale and ObjectivesHigh mammographic density reduces the diagnostic accuracy of screening mammography due to masking of tumors, resulting in possible delayed diagnosis and missed cancers. Women with high masking risk could be preselected for alternative screening regimens less susceptible to masking. In this study, various models to predict masking status are presented based on biometric and image-based parameters.Materials and MethodsFor a cohort of 67 nonscreen-detected (cancers detected via other means after a negative mammogram) and 147 screen-detected invasive cancers, quantitative volumetric breast density, BI-RADS density, and the distribution and appearance of dense tissue through statistical and texture metrics were measured. Age and Body Mass Index were recorded. Stepwise multivariate logistic regressions were computed to select those parameters that predicted nonscreen-detected cancers. Accuracy of the models was evaluated using the area under receiver operator characteristic curve (AUC).ResultsUsing BI-RADS density alone to predict masking risk yielded an AUC of 0.64 (95% confidence interval [0.57–0.70]). Age-adjusted BI-RADS density or volumetric breast density had AUCs of 0.72 [0.64–0.79] and 0.71 [0.62–0.78], respectively. A model extracted from the full pool of variables had an AUC of 0.75 [0.67–0.82].ConclusionThe optimal model predicts masking more accurately than density alone, suggesting that texture metrics may be useful in models to guide a stratified screening strategy.
       
  • Letter to the Editor: Women Representation on Radiology Journal Editorial
           Boards
    • Abstract: Publication date: Available online 9 August 2018Source: Academic RadiologyAuthor(s): Prachi P. Agarwal, Sowmya Balasubramanian, Deborah Levine, Ella A Kazerooni, M Elizabeth Oates
       
  • Musculoskeletal Radiology Fellowship Application and Selection Process:
           Perceptions of Residents, Fellows, and Fellowship Directors
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Jennifer L. Demertzis, Jonathan C. Baker, Michael V. Friedman, Charles S. Resnik, Theodore T. Miller, David A. RubinRational and ObjectivesThis study aimed to assess resident, fellow, and fellowship director perceptions of the musculoskeletal (MSK) radiology fellowship application process.Materials and MethodsA task group constructed three surveys with questions about current and “ideal” fellowship application and selection processes. Surveys were distributed to MSK fellowship directors, who were also asked to give separate surveys to current fellows. US and Canadian radiology residency directors were asked to distribute surveys to current R3 and R4 residents. Responses were tabulated and analyzed.ResultsResponses were received from 47 MSK fellowship directors, 73 MSK fellows, and 147 residents. Fellowship directors and fellows reported that most fellowship offers occur between July and September of the R3 year, although 19% of directors made offers as early as the R2 year. Of the 43 director respondents, 31 (72%) noted “pressure from other programs” as the main driving force behind their policies, but 28 (65%) felt that their timelines were “too early.” A formal match was supported by 55% of responding fellowship directors, 57% of fellows, and 61.9% of residents, citing “fairness” as a major justification.ConclusionsMSK radiology fellowship selection occurs as early as the R2 year, before many residents have had substantial exposure to different subspecialties. An “arms race” has developed with programs moving their timelines earlier in response to the actions of other programs, presumably to avoid missing the best candidates. Although a majority of respondents would support a formalized match to increase fairness, there is not universal agreement that it would be the best approach.
       
  • Rethinking the PGY-1 Basic Clinical Year: A Canadian National Survey of
           Its Educational Value for Diagnostic Radiology Residents
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Kathryn E. Darras, Abigail A. Arnold, Colin Mar, Bruce B. Forster, Linda Probyn, Silvia D. ChangRationale and ObjectivesRecently, the relevance of the postgraduate year 1 (PGY-1) Basic Clinical Year for radiology residents has been questioned. The purpose of this study was to determine the attitude of radiologists and trainees toward this year and which clinical rotations they perceived as most valuable to clinical practice.Materials and MethodsFollowing institutional review board approval, an anonymous online survey was administered to Canadian radiologists and radiology trainees. In addition to reporting demographic information, respondents were asked to rank the usefulness of individual rotations on a five-point Likert scale. To assess whether there are differences in the ratings and therefore rankings of the rotations by gender, position, and level of training, the Kruskal-Wallis one-way analysis of variance test was used with significance defined as P 
       
  • Machine Learning Algorithms Utilizing Quantitative CT Features May Predict
           Eventual Onset of Bronchiolitis Obliterans Syndrome After Lung
           Transplantation
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Eduardo J. Mortani Barbosa, Maarten Lanclus, Wim Vos, Cedric Van Holsbeke, William De Backer, Jan De Backer, James LeeRationale and ObjectivesLong-term survival after lung transplantation (LTx) is limited by bronchiolitis obliterans syndrome (BOS), defined as a sustained decline in forced expiratory volume in the first second (FEV1) not explained by other causes. We assessed whether machine learning (ML) utilizing quantitative computed tomography (qCT) metrics can predict eventual development of BOS.Materials and MethodsPaired inspiratory-expiratory CT scans of 71 patients who underwent LTx were analyzed retrospectively (BOS [n = 41] versus non-BOS [n = 30]), using at least two different time points. The BOS cohort experienced a reduction in FEV1 of>10% compared to baseline FEV1 post LTx. Multifactor analysis correlated declining FEV1 with qCT features linked to acute inflammation or BOS onset. Student t test and ML were applied on baseline qCT features to identify lung transplant patients at baseline that eventually developed BOS.ResultsThe FEV1 decline in the BOS cohort correlated with an increase in the lung volume (P = .027) and in the central airway volume at functional residual capacity (P = .018), not observed in non-BOS patients, whereas the non-BOS cohort experienced a decrease in the central airway volume at total lung capacity with declining FEV1 (P = .039). Twenty-three baseline qCT parameters could significantly distinguish between non-BOS patients and eventual BOS developers (P 
       
  • Computed Tomography Window Blending: Feasibility in Thoracic Trauma
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Jacob C. Mandell, Jeremy R. Wortman, Tatiana C. Rocha, Les R. Folio, Katherine P. Andriole, Bharti KhuranaRationale and ObjectivesThis study aims to demonstrate the feasibility of processing computed tomography (CT) images with a custom window blending algorithm that combines soft-tissue, bone, and lung window settings into a single image; to compare the time for interpretation of chest CT for thoracic trauma with window blending and conventional window settings; and to assess diagnostic performance of both techniques.Materials and MethodsAdobe Photoshop was scripted to process axial DICOM images from retrospective contrast-enhanced chest CTs performed for trauma with a window-blending algorithm. Two emergency radiologists independently interpreted the axial images from 103 chest CTs with both blended and conventional windows. Interpretation time and diagnostic performance were compared with Wilcoxon signed-rank test and McNemar test, respectively. Agreement with Nexus CT Chest injury severity was assessed with the weighted kappa statistic.ResultsA total of 13,295 images were processed without error. Interpretation was faster with window blending, resulting in a 20.3% time saving (P 
       
  • The Yellow Scale Is Superior to the Gray Scale for Detecting Acute
           Ischemic Stroke on a Monitor Display in Computed Tomography
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Akio Ogura, Katsumi Hayakawa, Yoshito Tsushima, Fumie Maeda, Aoi Kamakura, Kunihiko KatagiriRationale and ObjectivesThe purpose of this study was to compare the efficacy of the color scale with regard to focal detection with computed tomography in acute ischemic stroke.Materials and MethodsComputed tomography images of the brain of 19 patients diagnosed with acute stroke, based on magnetic resonance diffusion-weighted images obtained within an onset of 24 hours, and the images of five normal patients were displayed in each color look-up table on a monitor. The detection of acute stroke was compared among 15 radiologists. The images were compared in the gray, green, yellow, red, and blue scales of the look-up tables. The observers recorded acute ischemic stroke as “present” or “absent.” They also located the position of the stroke lesion and described the degree of their conviction as to whether a lesion existed. Detection was evaluated by receiver operating characteristic analysis. The area under the receiver operating characteristic curves was compared. In addition, reduced fatigue and the ease in image observation were compared.ResultsCompared to the other scales, the yellow scale had a significantly higher area under the receiver operating characteristic curve, which indicated that this scale allowed better detection of acute ischemic stroke. The gray scale produced the least fatigue in image observation.ConclusionsThe detection of acute ischemic stroke is improved by changing the display monitor from the gray scale to the yellow scale. From the perspective of color psychology, yellow is associated with higher arousal, cheerfulness, confidence, creativity, and excitement. Therefore, the yellow scale may be suitable for a medical imaging display.
       
  • Neurometabolites Alteration in the Acute Phase of Mild Traumatic Brain
           Injury (mTBI): An In Vivo Proton Magnetic Resonance Spectroscopy (1H-MRS)
           Study
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Vigneswaran Veeramuthu, Pohchoo Seow, Vairavan Narayanan, Jeannie Hsiu Ding Wong, Li Kuo Tan, Aditya Tri Hernowo, Norlisah RamliRationale and ObjectivesMagnetic resonance spectroscopy is a noninvasive imaging technique that allows for reliable assessment of microscopic changes in brain cytoarchitecture, neuronal injuries, and neurochemical changes resultant from traumatic insults. We aimed to evaluate the acute alteration of neurometabolites in complicated and uncomplicated mild traumatic brain injury (mTBI) patients in comparison to control subjects using proton magnetic resonance spectroscopy (1H magnetic resonance spectroscopy).Material and MethodsForty-eight subjects (23 complicated mTBI [cmTBI] patients, 12 uncomplicated mTBI [umTBI] patients, and 13 controls) underwent magnetic resonance imaging scan with additional single voxel spectroscopy sequence. Magnetic resonance imaging scans for patients were done at an average of 10 hours (standard deviation 4.26) post injury. The single voxel spectroscopy adjacent to side of injury and noninjury regions were analysed to obtain absolute concentrations and ratio relative to creatine of the neurometabolites. One-way analysis of variance was performed to compare neurometabolite concentrations of the three groups, and a correlation study was done between the neurometabolite concentration and Glasgow Coma Scale.ResultsSignificant difference was found in ratio of N-acetylaspartate to creatine (NAA/Cr + PCr) (χ2(2) = 0.22, P 
       
  • Association of Focal Radiation Dose Adjusted on Cross Sections with
           Subsolid Nodule Visibility and Quantification on Computed Tomography
           Images Using AIDR 3D: Comparison Among Scanning at 84, 42, and 7 mAs
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Yukihiro Nagatani, Hiroshi Moriya, Satoshi Noma, Shigetaka Sato, Shinsuke Tsukagoshi, Tsuneo Yamashiro, Mitsuhiro Koyama, Noriyuki Tomiyama, Yoshiharu Ono, Sadayuki Murayama, Kiyoshi Murata, Mitsuhiro Koyama, Yoshifumi Narumi, Masahiro Yanagawa, Osamu Honda, Noriyuki Tomiyama, Yoshiharu Ohno, Kazuro Sugimura, Kotaro Sakuma, Hiroshi MoriyaRationale and ObjectivesThe objectives of this study were to compare the visibility and quantification of subsolid nodules (SSNs) on computed tomography (CT) using adaptive iterative dose reduction using three-dimensional processing between 7 and 42 mAs and to assess the association of size-specific dose estimate (SSDE) with relative measured value change between 7 and 84 mAs (RMVC7–84) and relative measured value change between 42 and 84 mAs (RMVC42–84).Materials and MethodsAs a Japanese multicenter research project (Area-detector Computed Tomography for the Investigation of Thoracic Diseases [ACTIve] study), 50 subjects underwent chest CT with 120 kV, 0.35 second per location and three tube currents: 240 mA (84 mAs), 120 mA (42 mAs), and 20 mA (7 mAs). Axial CT images were reconstructed using adaptive iterative dose reduction using three-dimensional processing. SSN visibility was assessed with three grades (1, obscure, to 3, definitely visible) using CT at 84 mAs as reference standard and compared between 7 and 42 mAs using t test. Dimension, mean CT density, and particular SSDE to the nodular center of 71 SSNs and volume of 58 SSNs (diameter>5 mm) were measured. Measured values (MVs) were compared using Wilcoxon signed-rank tests among CTs at three doses. Pearson correlation analyses were performed to assess the association of SSDE with RMVC7–84: 100 × (MV at 7 mAs − MV at 84 mAs)/MV at 84 mAs and RMVC42–84.ResultsSSN visibilities were similar between 7 and 42 mAs (2.76 ± 0.45 vs 2.78 ± 0.40) (P = .67). For larger SSNs (>8 mm), MVs were similar among CTs at three doses (P > .05). For smaller SSNs (
       
  • Incidental Thyroid Nodules in the National Lung Screening Trial:
           Estimation of Prevalence, Malignancy Rate, and Strategy for Workup
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Manisha BahlRationale and ObjectivesThere is limited research on the prevalence of incidental thyroid nodules (ITNs) in the United States screening population and on the appropriate evaluation of computed tomography (CT)-detected ITNs. The purpose of this study is to determine the prevalence of ITNs in the National Lung Screening Trial (NLST) and develop a workup strategy for ITNs.Materials and MethodsCT images were obtained for subjects with documented thyroid abnormalities in the CT screening arm of the NLST, subjects diagnosed with thyroid malignancies, and control subjects. Several size thresholds were compared to determine how many nodules would be further evaluated and how many thyroid malignancies would be missed had each threshold been applied at the time of workup.ResultsThyroid nodules were reported in 0.7% (117 of 17,309 subjects). In 663 control subjects without reported thyroid nodules, thyroid nodules were identified in 78 (11.8%). Reported nodules were larger than unreported nodules (21.3 vs 16.9 mm, P = .03). Thyroid malignancies were diagnosed in 0.1% (22 of 17,309). If a 20-mm rather than a 10-mm cutoff were used to determine which nodules should be further evaluated, all malignancies would be detected, but 24 rather than 62 patients would require workup, for a workup reduction rate of 48.7% (38 of 78).ConclusionsLess than 1% of subjects in the NLST had reported ITNs. The true prevalence of ITNs was estimated to be 11.8%, which provides a better approximation of the number of patients who could potentially receive workup. A 20-mm rather than a 10-mm cutoff would reduce the workup rate by almost 50% while still capturing all malignancies.
       
  • Reinforcing the Importance and Feasibility of Implementing a Low-dose
           Protocol for CT-guided Biopsies
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Eric J. Keller, Robert J. Lewandowski, Lee Goodwin, Vahid Yaghmai, Albert Nemcek, James C. Carr, Jeremy D. CollinsRationale and ObjectivesThis study sought to more definitely illustrate the impact and feasibility of implementing a low-dose protocol for computed tomography (CT)-guided biopsies using size-specific dose estimates and multivariate analyses.Materials and MethodsFifty consecutive CT-guided lung and extrapulmonary biopsies were reviewed before and after implementation of a low-dose protocol (200 patients total, mean age 61 ± 15 years, 128 women). Analyses of variance with Bonferroni correction were used to compare standard and low-dose protocols in terms of patient demographics, physician experience, target lesion size, total dose-length product, total acquisitions, size-specific dose estimate, signal-to-noise ratio, contrast-to-noise ratio, and lesion conspicuity ratings. All procedures were performed on the same 16-slice CT scanner.ResultsVoluntary protocol adherence was 100% (lung) and 89% (extrapulmonary). The low-dose protocol achieved significantly lower total average dose-length product [(lung) 735.6 ± 599.4 mGy × cm to 252.1 ± 101.9 mGy × cm, P 
       
  • A Dynamic Graph Cuts Method with Integrated Multiple Feature Maps for
           Segmenting Kidneys in 2D Ultrasound Images
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Qiang Zheng, Steven Warner, Gregory Tasian, Yong FanRationale and ObjectivesAutomatic segmentation of kidneys in ultrasound (US) images remains a challenging task because of high speckle noise, low contrast, and large appearance variations of kidneys in US images. Because texture features may improve the US image segmentation performance, we propose a novel graph cuts method to segment kidney in US images by integrating image intensity information and texture feature maps.Materials and MethodsWe develop a new graph cuts-based method to segment kidney US images by integrating original image intensity information and texture feature maps extracted using Gabor filters. To handle large appearance variation within kidney images and improve computational efficiency, we build a graph of image pixels close to kidney boundary instead of building a graph of the whole image. To make the kidney segmentation robust to weak boundaries, we adopt localized regional information to measure similarity between image pixels for computing edge weights to build the graph of image pixels. The localized graph is dynamically updated and the graph cuts-based segmentation iteratively progresses until convergence. Our method has been evaluated based on kidney US images of 85 subjects. The imaging data of 20 randomly selected subjects were used as training data to tune parameters of the image segmentation method, and the remaining data were used as testing data for validation.ResultsExperiment results demonstrated that the proposed method obtained promising segmentation results for bilateral kidneys (average Dice index = 0.9446, average mean distance = 2.2551, average specificity = 0.9971, average accuracy = 0.9919), better than other methods under comparison (P 
       
  • Intravoxel Incoherent Motion Diffusion-weighted MR Imaging for Early
           Evaluation of the Effect of Radiofrequency Ablation in Rabbit Liver VX2
           Tumors
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Lian Shanshan, Shi Feng, Wei Kaikai, Zhang Yijun, Liu Huiming, Xie ChuanmiaoRationale and ObjectivesThis study aims to investigate the value of intravoxel incoherent motion (IVIM)-derived parameters for early evaluation of the efficiency of radiofrequency ablation (RFA) treatment for rabbit liver VX2 tumor.Materials and MethodsEighteen rabbit liver VX2 tumor models were constructed, and computed tomography–guided RFA was performed. One day before and 7 days after RFA, 18 models underwent magnetic resonance imaging, including contrast-enhanced imaging and IVIM diffusion-weighted imaging with 16 b-factors (0–1000 s/mm2). Post-RFA liver tumors were segmented into viable tumor, inflammatory reaction, and ablation necrotic regions according to gross and histopathologic examinations. Parameters derived from IVIM were calculated. One-way analysis of variance and least significant difference test were used for comparisons among the three regions. The diagnostic performance of parameters was evaluated using receiver operating characteristic (ROC) analysis.ResultsADCtotal, D, and f values were significantly lower in viable tumor than in inflammatory reaction regions (all P 
       
  • An MRI-based Radiomics Classifier for Preoperative Prediction of Ki-67
           Status in Breast Cancer
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Cuishan Liang, Zixuan Cheng, Yanqi Huang, Lan He, Xin Chen, Zelan Ma, Xiaomei Huang, Changhong Liang, Zaiyi LiuRationale and ObjectivesThis study aims to investigate the value of a magnetic resonance imaging–based radiomics classifier for preoperatively predicting the Ki-67 status in patients with breast cancer.Materials and MethodsWe chronologically divided 318 patients with clinicopathologically confirmed breast cancer into a training dataset (n = 200) and a validation dataset (n = 118). Radiomics features were extracted from T2-weighted (T2W) and contrast-enhanced T1-weighted (T1+C) images of breast cancer. Radiomics feature selection and radiomics classifiers were generated using the least absolute shrinkage and selection operator regression analysis method. The correlation between the radiomics classifiers and the Ki-67 status in patients with breast cancer was explored. The predictive performances of the radiomics classifiers for the Ki-67 status were evaluated with receiver operating characteristic curves in the training dataset and validated in the validation dataset.ResultsThrough the radiomics feature selection, 16 and 14 features based on T2W and T1+C images, respectively, were selected to constitute the radiomics classifiers. The radiomics classifier based on T2W images was significantly correlated with the Ki-67 status in both the training and the validation datasets (both P 
       
  • Cultivating Future Radiology Educators: Development and Implementation of
           a Clinician-Educator Track for Residents
    • Abstract: Publication date: September 2018Source: Academic Radiology, Volume 25, Issue 9Author(s): Dexter Mendoza, Ryan Peterson, Christopher Ho, Peter Harri, Deborah Baumgarten, Mark E. MullinsEffective and dedicated educators are critical to the preservation and advancement of the practice of radiology. The need for innovative and adaptable educators is increasingly being recognized, with several institutions granting academic promotions through clinician-educator tracks. The implementation of resident “clinician-educator tracks” or “teaching tracks” should better prepare residents aspiring to become academic radiologists focused on teaching. In this work, we describe our experience in the development and implementation of a clinician-educator track for diagnostic radiology residents at our institution.
       
  • Lesion Nonvisualization at MRI-Guided Breast Biopsy: Now What'
    • Abstract: Publication date: Available online 29 July 2018Source: Academic RadiologyAuthor(s): Colleen H. Neal
       
  • Low Dose Lung CT Screening in an Asian Population
    • Abstract: Publication date: Available online 13 July 2018Source: Academic RadiologyAuthor(s): David P. Naidich
       
  • Learning How Professionalism Evolves: Lessons From the Law
    • Abstract: Publication date: Available online 15 June 2018Source: Academic RadiologyAuthor(s): Richard B. Gunderman, Mark J. Mutz
       
  • Single Injection Dual-Phase Cone Beam CT (DP-CBCT): Vascular Anatomy
           Assessment and Occult Nodule Detection; Have We Reached the Focus'
    • Abstract: Publication date: Available online 12 June 2018Source: Academic RadiologyAuthor(s): Pierleone Lucatelli, Gianluca De Rubeis, Renato Argirò, Mario Corona, Mario Bezzi
       
 
 
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