Showing papers in "Journal of Computer Assisted Tomography in 2019"

Clinical Applications of Arterial Spin Labeling in Brain Tumors.

Abstract: The aim of this review was to review the basic background, technique, and clinical applications of arterial spin labeling in brain tumors. Arterial spin labeling is used for differentiation of brain tumors from nonneoplastic lesions such as infarction and infection. It has a role in the grading of gliomas and in the differentiation of gliomas from lymphomas and metastasis. It is used for detection of the best biopsy site and prediction of treatment response. Arterial spin labeling is used for the assessment of extra-axial tumors and pediatric tumors. Last, it has a role in the differentiation of tumor recurrence from postradiation changes and in monitoring patients after therapy.

Radiomics for Classifying Histological Subtypes of Lung Cancer Based on Multiphasic Contrast-Enhanced Computed Tomography.

Abstract: Objectives The aim of this study was to evaluate the performance of the radiomics method in classifying lung cancer histological subtypes based on multiphasic contrast-enhanced computed tomography (CT) images. Methods A total of 229 patients with pathologically confirmed lung cancer were retrospectively recruited. All recruited patients underwent nonenhanced and dual-phase chest contrast-enhanced CT; 1160 quantitative radiomics features were calculated to build a radiomics classification model. The performance of the classification models was evaluated by the receiver operating characteristic curve. Results The areas under the curve of radiomics models in classifying adenocarcinoma and squamous cell carcinoma, adenocarcinoma and small cell lung cancer, and squamous cell carcinoma and small cell lung cancer were 0.801, 0.857, and 0.657 (nonenhanced); 0.834, 0.855, and 0.619 (arterial phase); and 0.864, 0.864, and 0.664 (venous phase), respectively. Moreover, the application of contrast-enhanced CT may affect the selection of radiomics features. Conclusions Our study indicates that radiomics may be a promising tool for noninvasive predicting histological subtypes of lung cancer based on the multiphasic contrast-enhanced CT images.

Current Update on Desmoid Fibromatosis

Abstract: Objective The purpose of this article is to review the etiopathogenesis, molecular cytogenetics, histopathology, clinical features, and multimodality imaging features of desmoid fibromatosis. Recent advances in the management of desmoid fibromatosis will also be discussed. Conclusions Desmoid fibromatosis is a rare soft tissue neoplasm with a high incidence of local recurrence. Imaging plays an important role in the diagnosis and management of this disease.

Imaging of Brain Infarctions: Beyond the Usual Territories.

Abstract: In this review, our intension is to present imaging features of several categories of uncommon cases of brain infarctions including infarctions associated with neurovascular variants, infarctions along small arterial territories, and brainstem stroke syndromes. Infarctions associated with neurovascular variants include azygos anterior cerebral artery territory infarction and artery of Percheron infarction. In the second group, we discuss anterior choroidal artery infarction and artery of Heubner infarction. The third group highlights brainstem stroke syndromes, including Claude and Benedikt syndromes due to midbrain infarction; Foville, Marie Foix, and locked-in syndromes due to pontine infarction; and Dejerine (medial medullary), bilateral medial medullary, and Wallenberg (lateral medullary) syndromes.

Diagnostic Value of Contrast-Enhanced Spectral Mammography in Comparison to Magnetic Resonance Imaging in Breast Lesions.

Abstract: Objective The aim of this study was to evaluate the diagnostic value between contrast-enhanced spectral mammography (CESM) and breast magnetic resonance imaging (MRI) in breast disease. Methods Two hundred thirty-five patients who were suspected of having breast abnormalities by clinical examination or mammography underwent CESM and MRI examination. Using histopathologic results as the criterion standard, the diagnostic performance of CESM and MRI was investigated. The areas under receiver operating characteristic curves were applied to analyze diagnostic efficiency. The Pearson correlation coefficients between CESM versus pathology and MRI versus pathology were calculated. Results Two hundred sixty-three breast lesions were found in 235 patients, in which 177 were malignant and 86 were benign. By evaluating the diagnostic value, sensitivity, positive predictive value, negative predictive value, and false-negative rate from CESM examination were comparable to those from MRI (91.5%, 94.7%, 83.7%, and 8.5% vs 91.5%, 90.5%, 82.1%, and 8.5%). Importantly, the accuracy and the specificity were higher for CESM than those for MRI (81% and 89.5% vs 80.2% and 71.7%), whereas the false-positive rate was lower (10.5% vs 19.8%). The areas under receiver operating characteristic curves of CESM and MRI were 0.950 and 0.939, displaying the equivalent diagnostic efficiency (P = 0.48).For the agreement between measurements, mean tumor sizes were 3.1 cm for CESM and 3.4 cm for MRI compared with 3.2 cm on histopathologic results. The Pearson correlation coefficient of CESM versus histopathology (r = 0.774, P = 0.000) was consistent with MRI versus histopathology (r = 0.771, P = 0.000). Conclusions Our results show better accuracy, specificity, and false-positive rate of CESM in breast cancer detection than MRI. Contrast-enhanced spectral mammography displayed a good correlation with histopathology in assessing the lesion size of breast cancer, which is consistent with MRI.

Imaging of Moyamoya Disease and Moyamoya Syndrome: Current Status.

Abstract: Moyamoya disease (MMD) and Moyamoya syndrome (MMS) are referring to a progressive steno-occlusive vasculopathy at terminal portions of the bilateral internal carotid arteries and their proximal branches with prominent collateral artery formation. They can be found throughout the world and cause irreversible damage to the cerebral hemodynamics due to the progressive nature. Prompt diagnosis and accurate assessment could significantly improve the prognosis of MMD and MMS. Some imaging modalities could be used for diagnosis and nonquantitative evaluation of MMD and MMS, such as conventional computed tomography (CT) and magnetic resonance imaging (MRI), digital subtraction angiography, CT angiography (CTA), and magnetic resonance angiography. Some could quantitatively evaluate the cerebral hemodynamics of MMD and MMS, such as single-photon emission CT, positron emission tomography, xenon-enhanced CT, perfusion CT, dynamic susceptibility contrast MRI, arterial spin labeling MRI, and the hemodynamic parameters measured by those imaging methods could guide treatment of MMD and MMS. All the imaging modalities have their merits and demerits, and they can play a part in certain situation. We need establish standardized protocols for preoperative and postoperative evaluation with different imaging techniques in the further science for MMD and MMS.

Computed Tomography Angiography and Magnetic Resonance Angiography of Congenital Anomalies of Pulmonary Veins.

Abstract: We aimed to review computed tomography and magnetic resonance angiography of congenital anomalies of pulmonary veins. Total anomalous pulmonary venous return shows all pulmonary veins drain abnormally in another site rather than left atrium. Imaging can detect anomalous veins either supracardiac, infracardiac, or mixed. Partial anomalous pulmonary venous return shows some pulmonary vein have abnormal drainage that well delineated with computed tomography angiography. Scimitar syndrome is a type of partial anomalous pulmonary venous return where the pulmonary veins of the right lung drain infracardiac and is associated with right lung hypoplasia and dextrocardia. Pseudoscimitar show anomalous vein that takes a tortuous course and drains into the left atrium producing a false-positive scimitar sign. Cor triatriatum shows septum divide left atrium with proximal chamber receives blood flow from the pulmonary veins. Levoatriocardinal vein is an anomalous connection between the left atrium and anomalous vein from systemic venous system that is embryo logically derived from the cardinal veins. Computed tomography angiography can detect pulmonary vein stenosis, atresia, hypoplasia, and varix. Imaging is important for intimal diagnosis and detects the anomalous vessels and its connection, presence of stenosis, and associated other congenital cardiac anomalies. Also, it is a great role in assessment of patients after surgery.

Whole-Body Computed Tomography Using Low-Dose Biphasic Injection Protocol With Adaptive Statistical Iterative Reconstruction V: Assessment of Dose Reduction and Image Quality in Trauma Patients.

Abstract: AIM This study aimed to evaluate potential dose savings on a revised protocol for whole-body computed tomography and image quality after implementing Adaptive Statistical Iterative Reconstruction V (ASiR-V) algorism for trauma patients and compare it with routine protocol. MATERIALS AND METHODS One hundred trauma patients were classified into 2 groups using 2 different scanning protocols. Group A (n = 50; age, 32.48 ± 8.09 years) underwent routine 3-phase protocol. Group B (n = 50; age, 35.94 ± 13.57 years) underwent biphasic injection protocol including unenhanced scan for the brain and cervical spines, followed by a 1-step acquisition of the thorax, abdomen, and pelvis. The ASiR-V level was kept at 50% for all examinations, and then studies were reconstructed at 0% ASiR-V level. Radiation dose, total acquisition time, and image count were compared between groups (A and B). Two radiologists independently graded image quality and artifacts between both groups and 2 ASiR-V levels (0 and 50%). RESULTS The mean (±SD) dose-length product value for postcontrast scans in group A was 1602.3 ± 271.8 mGy · cm and higher when compared with group B (P < 0.001), which was 951.1 ± 359.6 mGy · cm. Biphasic injection protocol gave a dose reduction of 40.4% and reduced the total acquisition time by 11.4% and image count by 37.6%. There was no statistically significant difference between the image quality scores for both groups; however, group A scored higher grades (4.62 ± 0.56 and 4.56 ± 0.67). Similarly, the image quality scores for both ASiR-V levels in both groups were not significantly different. CONCLUSIONS Biphasic computed tomography protocol reduced radiation dose with maintenance of diagnostic accuracy and image quality after implementing ASiR-V algorism.

Semiautomated Characterization of Carotid Artery Plaque Features From Computed Tomography Angiography to Predict Atherosclerotic Cardiovascular Disease Risk Score.

Abstract: Purpose To investigate whether selected carotid computed tomography angiography (CTA) quantitative features can predict 10-year atherosclerotic cardiovascular disease (ASCVD) risk scores. Methods One hundred seventeen patients with calculated ASCVD risk scores were considered. A semiautomated imaging analysis software was used to segment and quantify plaque features. Eighty patients were randomly selected to build models using 14 imaging variables and the calculated ASCVD risk score as the end point (continuous and binarized). The remaining 37 patients were used as the test set to generate predicted ASCVD scores. The predicted and observed ASCVD risk scores were compared to assess properties of the predictive model. Results Nine of 14 CTA imaging variables were included in a model that considered the plaque features in a continuous fashion (model 1) and 6 in a model that considered the plaque features dichotomized (model 2). The predicted ASCVD risk scores were 18.87% ± 13.26% and 18.39% ± 11.6%, respectively. There were strong correlations between the observed ASCVD and the predicted ASCVDs, with r = 0.736 for model 1 and r = 0.657 for model 2. The mean biases between observed ASCVD and predicted ASCVDs were -1.954% ± 10.88% and -1.466% ± 12.04%, respectively. Conclusions Selected quantitative imaging carotid features extracted from the semiautomated carotid artery analysis can predict the ASCVD risk scores.

Imaging Findings of Klippel-Trenaunay Syndrome.

Abstract: We aim to review the imaging findings of Klippel-Trenaunay syndrome. This disorder characterized clinically by a triad of capillary malformations manifesting as a port-wine stain, venous varicosities typically along the lateral aspect of the lower extremities, and bone and/or soft tissue hypertrophy. Imaging of extremities shows unilateral venous varicosities, persistent embryonic veins, anomalous of the superficial and deep venous system, low-flow venolymphatic malformations, and bony and soft tissue hypertrophy. Other findings include neurospinal as cavernoma, aneurysm, and hemimegalencephaly, pulmonary as pulmonary thromboembolism and pulmonary hypertension and visceral as gastrointestinal and genitourinary vascular anomalies. Imaging may detect associated lesions and differentiate from simulating lesions.

Comparison of Navigator Triggering Reduced Field of View and Large Field of View Diffusion-Weighted Imaging of the Pancreas.

Abstract: RATIONALE AND OBJECTIVES The purpose of this study is to compare image quality, presence and grade of artifacts, signal-to-noise ratio, and apparent diffusion coefficient (ADC) values in pancreatic tissue between high-resolution navigator-triggered (NT) restricted field of view (rFOV) FOCUS single-shot (SS) echo-planar imaging (EPI) diffusion-weighted imaging (DWI) and NT large FOV SS-EPI DWI. MATERIALS AND METHODS Magnetic resonance imaging examinations were performed with GE 3-T systems using a 32-channel body array coil. Seventeen consecutive patients were imaged. A 5-point scale semiquantitative grading system was used to evaluate image quality and general artifacts. Signal-to-noise ratio and ADC were measured in the head, body, and tail of the pancreas. Statistical analysis was performed using Student t test and Wilcoxon signed rank test, with differences considered significant for P value less than 0.05. RESULTS More artifacts were present on large FOV compared with rFOV FOCUS SS-EPI DW images (P < 0.01). Restricted field of view image quality was subjectively better (P < 0.01). No difference in the signal-to-noise ratio was demonstrated between the 2 image datasets. Apparent diffusion coefficient values were significantly lower (P < 0.01) when calculated from rFOV images than large FOV images. CONCLUSIONS Our results demonstrate better image quality and reduced artifacts in rFOV images compared with large FOV DWI. Measurements from ADC maps derived from rFOV DWI show significantly lower ADC values when compared with ADC maps derived from large FOV DWI.

Clinical and Payer-Based Analysis of Value of Dual-Energy Computed Tomography for Workup of Incidental Abdominal Findings.

Abstract: Objective To perform a clinical and payer-based analysis of the value of dual-energy computed tomography (DECT) for workup of incidental abdominal findings. Methods This was a single-center, retrospectively designed, Health Insurance Portability and Accountability Act-compliant study approved by our institutional review board. Sixty-nine examinations in 69 patients (45 men, 24 women; mean age, 57.7 years) who underwent single-phase postcontrast abdominal DECT studies between January 1, 2011, and December 31, 2017, were included. Two radiologists, blinded to study objective and design, reviewed all cases and identified incidental abdominal findings needing further imaging. All incidental findings were reviewed by 2 other investigators, who determined whether an imaging-based diagnosis could be made using DECT virtual noncontrast images and iodine maps. Additional studies and associated payer-reimbursement amounts avoided by use of DECT were estimated. All imaging costs were estimated based on the US Centers for Medicare & Medicaid Services reimbursement amounts. Results Thirty-four incidental findings (renal mass, n = 20; adrenal nodule, n = 8; pancreatic cystic lesions, n = 3; others, n = 3) were identified in 19 (27.5%) of 69 patients. Dual-energy computed tomography characterized 27 incidental findings in 15 patients and accounted for cost savings of 15 additional imaging examinations (abdominal magnetic resonance imaging, n = 11; abdominal computed tomography, n = 4). Based on Centers for Medicare & Medicaid Services reimbursement amounts, we estimated that, by abolishing the need for additional imaging use, DECT saved US $84.95 per patient. Conclusions Dual-energy computed tomography can provide an imaging-based diagnosis of incidental abdominal findings, otherwise incompletely characterized on routine abdominal computed tomography, in approximately 21% of patients. In select patients, the monetary savings from abolishing additional imaging may reduce payer costs associated with use of DECT.

Imaging of Pulmonary Atresia With Ventricular Septal Defect.

Abstract: The aim of this article was to review computed tomography angiography and magnetic resonance angiography of pulmonary atresia with ventricular septal defect. This disorder is a rare complex congenital heart disease. Preoperative imaging of pulmonary atresia with ventricular septal defect with computed tomography angiography and magnetic resonance angiography is important for complete anatomical delineation and planning for treatment. Preoperative imaging used for assessment of the main pulmonary artery (its size, valve, and confluence), aortopulmonary collaterals (its origin, insertion, course, and size), presence of patent ductus arteriosus, other sources of collaterals as bronchial and coronary arteries, and pattern of pulmonary arborization. Imaging can detect associated aortic, pulmonary venous and coronary anomalies, and other congenital heart disease. Postoperative imaging after unifocalization and stent is for assessment of patency, stenosis, and occlusion of stent or perivascular lesions as seroma.

Impact Analysis of the Routine Use of Dual-Energy Computed Tomography for Characterization of Incidental Renal Lesions

Abstract: Objective The aim of this study was to quantify the prevalence of incidental, indeterminate renal lesions on routine contrast-enhanced abdominal computed tomography (CT) and the proportion of such lesions that could be exonerated by dual-energy CT (DECT) postprocessing as benign hyperdense cysts. Methods The reports for 2729 consecutive contrast-enhanced DECT scans in the emergency department setting were reviewed for the mention of any renal lesion. For scans with a reported lesion, images were reviewed to assess for the presence of an indeterminate lesion that could not be definitively characterized as benign. All indeterminate lesions were reviewed with DECT postprocessing by 2 radiologists to assess for enhancement and other imaging characteristics and characterized by readers as benign or not definitively benign. Agreement between readers was assessed statistically, and disagreement was resolved by consensus. Results Two thousand seven hundred twenty-nine scans were performed in 2406 unique patients; a renal lesion was reported in 805 unique patient scans (33.4%). Review of these 805 scans led to discovery of 137 indeterminate lesions in 125 scans (5.2% of patients). Of the 137 lesions, 70 (51.1%) were classified as benign hyperdense cysts by readers, with the remaining 67 lesions classified as not definitively benign (43 solid masses, 9 Bosniak IIF cysts, 8 Bosniak III cysts, 7 Bosniak IV cysts). Conclusions Incidental indeterminate renal lesions are common on routine contrast-enhanced CT. More than half of these lesions could potentially be exonerated with DECT as benign Bosniak II cysts, which could avert the need for further workup in 2.8% of patients undergoing routine abdominal CT.

Imaging of Usual and Unusual Complication of Rotator Cuff Repair.

Abstract: Several complications may be encountered after rotator cuff (RC) repair. A thorough knowledge of surgical interventions, normal postoperative findings, and postoperative complications is crucial to provide a timely diagnosis, improving the clinical outcome of patients. Postoperative complications may involve RC, implanted device, osteochondral tissue, surgical-site infection, peripheral nerves, soft tissues, and vascular structures. In this review, we discuss the usual and unusual complications detectable after RC repair.

Comparison of Abdominal Computed Tomographic Enhancement and Organ Lesion Depiction Between Weight-Based Scanner Software Contrast Dosing and a Fixed-Dose Protocol in a Tertiary Care Oncologic Center.

Abstract: OBJECTIVE This study aimed to evaluate the quality of enhancement and solid-organ lesion depiction using weight-based intravenous (IV) contrast dosing calculated by injector software versus fixed IV contrast dose in oncologic abdominal computed tomographic (CT) examinations. METHODS This institutional review board-exempt retrospective cohort study included 134 patients who underwent single-phase abdominal CT before and after implementation of weight-based IV contrast injector software. Patient weight, height, body mass index, and body surface area were determined. Two radiologists qualitatively assessed examinations (4 indicating markedly superior to -4 indicating markedly inferior), and Hounsfield unit measurements were performed. RESULTS Enhancement (estimated mean, -0.05; 95% confidence interval [CI], -0.19 to 0.09; P = 0.46) and lesion depiction (estimated mean, -0.01; 95% CI, -0.10 to 0.07; P = 0.79) scores did not differ between CT examinations using weight-based IV contrast versus fixed IV contrast dosing when a minimum of 38.5 g of iodine was used. However, the scores using weight-based IV contrast dosing were lower when the injector software calculated and delivered less than 38.5 g of iodine (estimated mean, -0.81; 95% CI, -1.06 to -0.56; P < 0.0001). There were no significant differences in measured Hounsfield units between the CT examinations using weight-based IV contrast dosing versus fixed IV contrast dosing. CONCLUSIONS Oncologic CT image quality was maintained or improved with weight-based IV contrast dosing using injector software when using a minimum amount of 38.5 g of iodine.

Combining Clinical Characteristics and Specific Magnetic Resonance Imaging Features to Predict Placenta Accreta.

Abstract: Objective The aim of this study was to explore the independent clinical and magnetic resonance imaging (MRI) performance risk factors for predicting placenta accreta. Methods From January 2012 to December 2015, we retrospectively reviewed the clinical characteristics and MRI features of 97 patients. Of these, 42 were confirmed to be placenta accreta by pathological results or cesarean delivery findings. We tried to identify the independent risk factors by multivariate logistic regression model for significant differences in variables determined by univariate analysis. Results The multivariate logistic regression model indicated that 2 or more instances of previous cesarean deliveries and/or abortions, placenta previa, and placenta-myometrial interface interruption were independent risk factors for placenta accreta. The odd ratios were 3.79 for patients who had 2 or more instances of previous cesarean deliveries and/or abortions, 0.04 for marginal/partial placenta previa, 0.024 for complete placenta previa, and 6.56 for placenta-myometrial interface interruption. The values of accuracy and positive prediction by combination of a single clinical risk factor and placenta-myometrial interface interruption and of positive prediction by a combination of all 3 risk factors for predicting placenta accreta were raised to 83.5%, 75%, and 92.9%, respectively. We obtained 3 different risk groups by different combinations of all 3 risk factors. Conclusions The study suggested that 2 or more instances of previous cesarean deliveries and/or abortion, placenta previa, and placenta-myometrial interface interruption were independent risk factors for placenta accreta. A combination of a single clinical risk factor and an MRI risk factor can improve the diagnosis of placenta accreta, and a combination of all 3 risk factors could help recognize patients with placenta accreta.

Standardizing Magnetic Resonance Imaging Protocols, Requisitions, and Reports in Multiple Sclerosis: An Update for Radiologist Based on 2017 Magnetic Resonance Imaging in Multiple Sclerosis and 2018 Consortium of Multiple Sclerosis Centers Consensus Guidelines.

Abstract: The advent of magnetic resonance imaging has improved our understanding of the pathophysiology and natural course of multiple sclerosis (MS). The ability of magnetic resonance imaging to show the evolution of MS lesions on sequential scans has brought it to be one of the endpoints in clinical trials for disease-modifying therapies. Based on the most updated consensus guidelines from the American (Consortium of MS Centers) and European (Magnetic Resonance Imaging in MS) boards of experts in MS, this document shows the most relevant landmarks related to imaging findings, diagnostic criteria, indications to obtain a magnetic resonance, scan protocols and sequence options for patients with MS. Although incorporating the knowledge derived from the research arena into the daily clinical practice is always challenging, in this article, the authors provide useful recommendations to improve the information contained in the magnetic resonance report oriented to facilitate communication between radiologists and specialized medical teams involved in MS patients' multidisciplinary care.

Comparing Arterial- and Venous-Phase Acquisition for Optimization of Virtual Noncontrast Images From Dual-Energy Computed Tomography Angiography

Abstract: BACKGROUND: Follow-up with computed tomographic angiography is recommended after endovascular aneurysm repair, exposing patients to significant levels of radiation and iodine contrast medium. Dual-energy computed tomography allows virtual noncontrast (VNC) images to be reconstructed from contrast-enhanced images using a software algorithm. If the VNC images are a good-enough approximation of true noncontrast (TNC) images, a reduction in radiation dose can be ensured through omitting a TNC scan. PURPOSE: To compare image quality of VNC images reconstructed from arterial phase and venous phase dual-energy computed tomographic angiography to TNC images and to assess which one is more suitable to replace TNC images. METHODS: Sixty-three consecutive patients were examined using a dual-energy computed tomography as elective follow-up after endovascular aneurysm repair. The examination protocol included 1 unenhanced and 2 contrast-enhanced scans (80 kV/Sn140 kV) of the aorta. Virtual noncontrast data sets were reconstructed from the arterial (A-VNC) and venous (V-VNC) phase scans, respectively. Mean attenuation and image noise were measured for TNC, A-VNC, and V-VNC images within regions of interest at 2 levels in the aorta, the liver, retroperitoneal fat, and psoas muscle. Subjective image quality was assessed on a 4-point scale by 2 blinded readers. RESULTS: The differences between A-VNC and TNC, and between A-VNC and V-VNC, were substantial aorta at the level of diaphragm and aorta at the level of renal arteries. The difference between V-VNC and TNC was, on the other hand, very small and not statistically significant for the renal artery aorta. For liver, fat, and muscle tissue, there were significant differences between both A-VNC and V-VNC compared with TNC, but findings were similar between A-VNC and V-VNC. CONCLUSIONS: Virtual noncontrast images based on venous-phase scans appear to be a more accurate representation of TNC scans than VNC images based on arterial-phase scans. (Less)

Comparison of Cone-Beam Computed Tomography and Multislice Computed Tomography in the Assessment of Extremity Fractures.

Abstract: Objectives The aims of this study were to evaluate the agreement between cone-beam computed tomography (CBCT) and multislice computed tomography for the characterization of extremity fractures and to compare image quality, radiation dose, and patient tolerance. Methods Thirty-six patients with suspected fracture affecting distal extremities or who required preoperative fracture assessment were enrolled prospectively. Each patient underwent CBCT and multislice computed tomography the same day. Both examinations were evaluated independently twice by 2 trained radiologists using the Muller AO classification for fracture characterization. Results Cohen κ coefficient for agreement between the imaging techniques was almost perfect for fracture characterization, κ = 0.94 [95% confidence interval, 0.91-0.98]. There was substantial to almost perfect agreement for secondary findings. Cone-beam computed tomography was well tolerated and significantly less irradiant and had better subjective image. Conclusions An excellent agreement between both imaging techniques was found. This confirms the ability of CBCT to assess fractures and its potential in the management of patients with distal limb trauma.

Updated Imaging Features of Dysplastic Cerebellar Gangliocytoma.

Abstract: OBJECTIVE The aim of this study was to perform an updated review of the imaging features of dysplastic cerebellar gangliocytoma (DCG). METHODS Imaging findings were retrospectively reviewed in 14 patients with DCG. The analysis included size, location, cyst formation, calcification, intralesional hemorrhage, enhancement pattern, and apparent diffusion coefficient (ADC). RESULTS In addition to revisiting many well-established imaging features of DCG, enhancement was much more common (64.3%) than previously reported, and small enhancing veins were also frequently encountered within or along the periphery of the lesions (50%). Dysplastic cerebellar gangliocytomas had an elevated ADC compared with normal cerebellum (967.8 ± 115.7 vs 770.4 ± 47.3 × 10 mm/s; P < 0.0001). CONCLUSIONS Enhancement on magnetic resonance imaging within DCG should be an accepted imaging finding rather than being viewed as uncommon or atypical. Dysplastic cerebellar gangliocytomas typically have an elevated ADC compared with normal cerebellum, which may assist in differentiation from other posterior fossa neoplasms.

Computerized Image Analysis to Differentiate Benign and Malignant Breast Tumors on Magnetic Resonance Diffusion Weighted Image: A Preliminary Study.

Abstract: PURPOSE This work aims to determine the feasibility of using a computer-aided diagnosis system to differentiate benign and malignant breast tumors on magnetic resonance diffusion-weighted image (DWI). MATERIALS AND METHODS Institutional review board approval was obtained. This retrospective study included 76 patients who underwent breast magnetic resonance imaging before neoadjuvant chemotherapy from March 10, 2017, to October 12, 2017, with a total of 80 breast tumors including 40 cases of breast cancers and 40 cases of benign breast tumors. The textural features of DWI images were analyzed. The area under the receiver operating characteristic curve was calculated to evaluate the diagnostic efficiency of texture parameters. Multiple linear regression analysis was used to determine the efficiency of texture parameters for distinguishing the 2 types of breast tumors. RESULTS Computer vision algorithms were applied to extract 67 imaging features from lesions indicated by a breast radiologist on DWI images. A total of 19 texture feature parameters, such as variance, standard deviation, intensity, and entropy, out of 67 texture parameters were statistically significant in the 2 sets of data (P < 0.05). By comparing the receiver operating characteristic curves, we found that the mean and relative deviations exhibited high diagnostic values in differentiating between benign and malignant tumors. The accuracy of Fisher discriminant analysis for the 2 types of breast tumors was 92.5%. CONCLUSIONS Breast lesions exhibit certain characteristic features in DWI images that can be captured and quantified with computer-aided diagnosis, which enables good discrimination of benign and malignant breast tumors.

Spectral Computed Tomography Imaging in the Differential Diagnosis of Lung Cancer and Inflammatory Myofibroblastic Tumor.

Abstract: OBJECTIVE The aim of this study was to explore the value of spectral computed tomography (CT) imaging in differentiating lung cancer from inflammatory myofibroblastic tumor (IMT). METHODS One hundred twelve patients with 96 lung cancers and 16 IMTs underwent spectral CT during arterial phase (AP) and venous phase (VP). The normalized iodine concentration in AP (NICAP) and VP (NICVP), slope of spectral Hounsfield unit curve in AP (λAP) and VP (λVP), and normalized iodine concentration difference between AP and VP (ICD) were calculated. The 2-sample t test compared quantitative parameters. Two readers qualitatively assessed lesion types according to imaging features. Receiver operating characteristic curves were generated to calculate sensitivity and specificity. Sensitivity and specificity of the qualitative and quantitative studies were compared. RESULTS The patients with IMT had significantly higher NICAP, NICVP, λAP, λVP, and ICD than did the patients with lung cancer (P < 0.05). The threshold NICVP of 0.425 would yield the highest sensitivity and specificity of 92.7% and 81.3%, respectively, for differentiating lung cancer from IMT. The logistic regression model produced from combining quantitative parameters NICAP, NICVP, λAP, and λVP provided a sensitivity and specificity of 100% and 81.3%, respectively, for differentiating lung cancer from IMT. CONCLUSIONS Spectral CT imaging with the quantitative analysis may help to increase the accuracy of differentiating lung cancer from IMT.

Cardiovascular Magnetic Resonance Provides Evidence of Abnormal Myocardial Strain and Primary Cardiomyopathy in Marfan syndrome.

Abstract: OBJECTIVE Marfan syndrome is an autosomal-dominant genetic disorder caused by mutations in the fibrillin-1 gene. The condition is a connective tissue disease that frequently involves the cardiovascular system. The existence of a primary cardiomyopathy in Marfan syndrome, however, is controversial. The aims of this study were to investigate the prevalence of left ventricular dysfunction with both transthoracic echocardiography and cardiovascular magnetic resonance (CMR) in a cohort of Marfan syndrome patients and to investigate patterns of myocardial strain across the cohort. METHODS We used an institutional database to identify all patients with a firm diagnosis of Marfan syndrome based on Ghent criteria. Inclusion required left ventricular ejection fraction (LVEF) to have been measured by both CMR and transthoracic echocardiography within 12 months of each other. Normal LVEF was defined as a value of >55% when measured by CMR. Velocity vector imaging was used to measure left ventricular longitudinal strain patterns by application of feature tracking to cine magnetic resonance images. Results were compared with data from 20 age-matched control subjects. RESULTS Sixty-nine Marfan syndrome patients met the inclusion criteria. The mean age was 35.4 ± 15.0 years, and 56.5% were male. The mean LVEF was 59.0% ± 7.0% by CMR and 59.1% ± 5.8% by echo. One-fifth of Marfan syndrome patients (15/69; 21.7%) had reduced function with LVEF ≤55% by CMR, but only 5 of these were identified by echo. Furthermore, echo identified 5 Marfan syndrome patients as having reduced LVEF in the presence of a normal LVEF by CMR. Some Marfan syndrome patients had abnormal longitudinal strain patterns even with LVEF within the reference range. CONCLUSIONS These data provide support for a primary cardiomyopathy in some Marfan syndrome patients. Cardiovascular magnetic resonance is more sensitive than echo for identifying cases with mild systolic dysfunction. Strain analysis may be more sensitive than simple LVEF assessment for identifying at-risk individuals.

Preoperative Computed Tomography Features of Intrahepatic Cholangiocarcinoma for Predicting Lymph Node Metastasis and Overall Survival.

Abstract: OBJECTIVES The aims of this study were to compare the difference of computed tomography (CT) features between intrahepatic cholangiocarcinomas (ICCs) with and without lymph node metastasis (LNM) and to construct a nomogram to predict LNM and overall survival preoperatively. METHODS Clinicopathological and contrast-enhanced CT features of 63 patients with ICC were analyzed. Multivariate logistic regression analysis was performed to construct a nomogram to predict LNM preoperatively. Survival curves were drawn with the Kaplan-Meier method, and survival difference was compared. RESULTS Intrahepatic cholangiocarcinomas with and without LNM differed significantly in clinical symptoms, tumor location, morphologic classification, arterial phase enhancement degree-mean, arterial phase enhancement degree-max, portal venous phase enhancement degree-max, equilibrium phase (EP) enhancement ratio, EP CT value-max, and EP CT value-max/liver. A nomogram based on morphologic classification, EP CT value-max, and EP enhancement ratio was constructed to predict LNM with an area under curve of 0.814 (P < 0.001). Patients with ICC with LNM risk of 0.20 or greater based on the nomogram showed a significantly poorer overall survival than those with LNM risk less than 0.20 (39.5 ± 5.2 vs 51.1 ± 4.7 months). CONCLUSIONS Preoperative CT features of ICCs differed significantly between those with and without LNM. Nomogram based on those features could predict LNM and overall survival even better than the N stage.

Kinematic Analysis of the Distal Radioulnar Joint in Asymptomatic Wrists Using 4-Dimensional Computed Tomography-Motion Pattern and Interreader Reliability.

Abstract: Purpose The aim of this study was to determine the normal measurement values and interobserver performance of the distal radioulnar joint during wrist pronation-supination using 4-dimensional computed tomography (CT). Methods Four-dimensional CT examinations were performed on the asymptomatic contralateral wrists of 10 patients with unilateral chronic wrist pain. Measurements were conducted using the modified radioulnar (mRU) line and epicenter (Epi) methods. Volar subluxation of the ulnar head was demonstrated with negative values. Wilcoxon rank sum test was used to determine the measurement changes. Interobserver agreements were assessed using interclass correlation coefficients. Results In pronation, mRU line measurements (median, 0.09; interquartile range, 0-0.15) were significantly larger than in supination (median, -0.1; interquartile range, -0.18 to 0; P = 0.008).The Epi measurements were not significantly different in pronation (median, 0.03; interquartile range, 0.01-0.07) and supination (median, 0.06; interquartile range, 0.01-0.1; P = 0.799). There was an excellent inter-observer agreement between the two readers using mRU and Epi methods in pronation (0.982, 0.898), midpoint (0.994, 0.827) and supination (0.989, 0.972) positions, respectively. Conclusions Using 4-dimensional CT examination, distal radioulnar joint kinematics in asymptomatic wrists demonstrate excellent interobserver agreements with increased volar ulnar subluxation with supination as detected using mRU, but not the Epi method.

Value of Dual-Energy Computed Tomography for Diagnosing Cervical Lymph Node Metastasis in Patients With Papillary Thyroid Cancer

Abstract: Objective The objective of this study was to determine the value of dual-energy computed tomography (DECT) for the diagnosis of cervical lymph node metastasis in papillary thyroid cancer. Methods The normalized iodine concentration (NIC) and the slope of the spectral Hounsfield unit curve (λHU) in the arterial and venous phases were measured using iodine-overlay images and spectral curves. Quantitative DECT data and qualitative conventional CT data were analyzed by radiologists. Results The best qualitative parameter for lymph node metastasis detection was obvious node enhancement, and the best quantitative parameter for detection was arterial-phase NIC, which showed high sensitivity, specificity, and accuracy values at an optimal threshold of 25.8%. The best combination of qualitative and quantitative parameters consisted of obvious enhancement and arterial-phase NIC; this combination showed a sensitivity of 90.8% and a specificity of 80.5%. Conclusions The DECT quantitative parameters NIC and λHU can be an additional tool to diagnose cervical lymph node metastasis.

Associations Between Apparent Diffusion Coefficient Values and the Prognostic Factors of Breast Cancer.

Abstract: Objectives Breast imaging can offer great information about breast cancer heterogeneity. The purpose of this study was to analyze the relationship between apparent diffusion coefficient (ADC) values and various prognostic factors and investigate whether ADC values are useful for breast cancer diagnosis, evaluation of treatment response, and determination of prognosis. Methods A total of 111 cases of breast cancer were included in this study. Magnetic resonance findings were recorded according to the Breast Imaging Reporting and Data System magnetic resonance imaging lexicon. Diffusion-weighted imaging rim sign and minimum, maximum, and difference ADC values (ADCdiff) were also evaluated. Results ADCdiff was related to all prognostic factors such as histological grade, Ki-67, tumor size, molecular subtype, axillary node metastasis, lymphvascular invasion, internal enhancement pattern, intratumoral high T2 signal, peritumoral edema, and diffusion-weighted imaging rim sign, whereas minimum and maximum ADC values showed variable associations. Conclusions Apparent diffusion coefficient values were shown to be correlated with many proven or possible prognostic factors of breast cancer. In particular, ADCdiff can reflect tumor heterogeneity and showed higher correlation.

Ovarian Cancer Genetics and Implications for Imaging and Therapy.

Abstract: Ovarian cancer is the second most common gynecologic malignancy in the United States. Ovarian cancer has a dismal prognosis when diagnosed at an advanced stage. Therapy for these cancers is determined not only by stage but also by their heterogeneous pathologic features, genetic mutations, and biology. In this review, we will discuss types of epithelial ovarian cancer, and their associated genetic mutations and the implications for imaging and treatment.

Intraosseous Hibernoma: Five Cases and a Review of the Literature

Abstract: We present 5 cases of intraosseous hibernoma, a rare benign tumor of brown fat. Our literature review reveals that the average age at presentation is 58.6 years, and 69.7% of patients are female. Lesions are most often located in the spine and pelvis. Computed tomography usually demonstrates sclerotic changes, although lesions can be lytic. Magnetic resonance imaging findings include heterogeneous T2 hyperintensity. Technetium 99m-methyl diphosphonate bone scan reveals variable radiotracer uptake, whereas 18F-labeled fluoro-2-deoxyglucose (FDG) PET-CT shows mild uptake. Intraosseous hibernoma should be considered when imaging demonstrates a fat-containing lesion in bone, especially one exhibiting FDG avidity.