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Aim: To assess the ability of dual-energy computed tomography (DECT) to distinguish benign from malignant ovarian tumours (OTs)., Materials and Methods: Following approval of the institutional review board, the institutional database was mined for treatment-naive patients who underwent primary cytoreduction for OT. Thirty-seven patients were included and divided into those with benign OTs (n = 11) and malignant OTs (n = 26), including high-grade (n = 20) and low-grade (n = 6) malignant OTs. Advanced processing and region of interest delineation on the ovarian mass were performed using the preoperative staging DECT examination using the Advantage Workstation. The pixel-level data of the CT attenuation values at 50, 70, and 120 keV and the effective atomic number (Z eff ), water content (WC), and iodine content (IC) in the ovarian mass were recorded. The Wilcoxon rank-sum test was used to compare CT attenuation data at different voltages, Z eff , and WC and IC levels between benign and malignant OTs and between high- and low-grade malignant OTs. Simple logistic regression was used to correlate the imaging characteristics with malignant status and grade., Results: Malignant OTs had significantly higher Z eff and IC compared with benign OTs. The threshold values for the diagnosis of malignant OT were IC≥9.74 (100 μg/cm 3 ) with 81% sensitivity and 73% specificity and Z eff ≥8.16 with 85% sensitivity and 73% specificity. High-grade OTs had significantly higher WC compared with low-grade OTs, and a threshold of ≥1,013.92 mg/cm 3 differentiated them with 80% sensitivity and 83% specificity., Conclusion: DECT may be a tool to help distinguish malignant and benign OTs and predict tumour grade., (Copyright © 2020 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Aim: To compare the efficacy of computed tomography (CT) texture analysis and conventional evaluation by radiologists for differentiation between large adrenal adenomas and carcinomas., Materials and Methods: Quantitative CT texture analysis was used to evaluate 54 histopathologically proven adrenal masses (mean size=5.9 cm; range=4.1-10 cm) from 54 patients referred to Anderson Cancer Center from January 2002 through April 2014. The patient group included 32 women (mean age at mass evaluation=59 years) and 22 men (mean age at mass evaluation=61 years). Adrenal lesions seen on precontrast and venous-phase CT images were labelled by three different readers, and the labels were used to generate intensity- and geometry-based textural features. The textural features and the attenuation values were considered as input values for a random forest-based classifier. Similarly, the adrenal lesions were classified by two different radiologists based on morphological criteria. Prediction accuracy and interobserver agreement were compared., Results: The textural predictive model achieved a mean accuracy of 82%, whereas the mean accuracy for the radiologists was 68.5% (p<0.0001). The interobserver agreements between the predictive model and radiologists 1 and 2 were 0.44 (p<0.0005; 95% confidence interval [CI]: 0.25-0.62) and 0.47 (p<0.0005; 95% CI: 0.28-0.66), respectively. The Dice similarity coefficient between the readers' image labels was 0.875±0.04., Conclusion: CT texture analysis of large adrenal adenomas and carcinomas is likely to improve CT evaluation of adrenal cortical tumours., (Copyright © 2019. Published by Elsevier Ltd.)

Purpose: Large adrenal masses pose a diagnostic dilemma. The purpose of this study was twofold: first, to assess the degree of interobserver agreement in evaluating the morphology of pathologically proven adrenal adenomas and adrenocortical carcinomas larger than 4 cm in diameter; and second, to identify morphologic characteristics that correlated with the pathologic diagnosis., Materials and Methods: For this blinded, retrospective study, we collected cases of 25 adrenal adenomas and 33 adrenocortical carcinomas measuring larger than 4 cm. Two radiologists evaluated morphologic characteristics of the lesions on CT. Interobserver agreement was evaluated using kappa statistics, and the correlation of imaging characteristics with the diagnosis was evaluated using a logistic regression model., Results: We found the highest interobserver agreement in the assessment of precontrast attenuation (Κ = 0.81) as well as substantial agreement in determining the shape and the presence of calcifications (Κ = 0.69 and 0.74, respectively). Readers agreed less often regarding the presence of fat (Κ = 0.48), as well as regarding the presence of necrosis, heterogeneity, and the overall impression (Κ = 0.15, 0.24, and 0.26, respectively). CT characteristics correlated with benignity included round shape (p = 0.02), an overall radiologic impression of a benign lesion (p < 0.0001), the presence of fat (p = 0.01), and a precontrast attenuation of less than 10 Hounsfield units (p < 0.0001). The latter two of these characteristics were highly specific for benign pathology (93% and 100%, respectively)., Conclusion: Our study suggests that CT has the ability to consistently identify characteristics significantly correlated with benign vs. malignant adrenal tumors.

Dual-energy CT imaging has many potential uses in abdominal imaging. It also has unique requirements for protocol creation depending on the dual-energy scanning technique that is being utilized. It also generates several new types of images which can increase the complexity of image creation and image interpretation. The purpose of this article is to review, for rapid switching and dual-source dual-energy platforms, methods for creating dual-energy protocols, different approaches for efficiently creating dual-energy images, and an approach to navigating and using dual-energy images at the reading station all using the example of a pancreatic multiphasic protocol. It will also review the three most commonly used types of dual-energy images: "workhorse" 120kVp surrogate images (including blended polychromatic and 70 keV monochromatic), high contrast images (e.g., low energy monochromatic and iodine material decomposition images), and virtual unenhanced images. Recent developments, such as the ability to create automatically on the scanner the most common dual-energy images types, namely new "Mono+" images for the DSDECT (dual-source dual-energy CT) platform will also be addressed. Finally, an approach to image interpretation using automated "hanging protocols" will also be covered. Successful dual-energy implementation in a high volume practice requires careful attention to each of these steps of scanning, image creation, and image interpretation.

Pelvic exenteration is a radical surgery that is used in an attempt to cure patients with locally advanced central pelvic malignancies. Exenteration is a salvage operation that is considered only after other therapies, such as chemoradiation, have been exhausted. The high morbidity from exenteration's multiorgan resection warrants careful patient selection. Preoperative imaging plays a major role in the selection process, allowing the exclusion of patients with unresectable pelvic disease or distant metastases. Imaging is also crucial to surgical planning, providing the surgeon with a map of the distribution and extent of the pelvic disease., (©RSNA, 2015.)

Peritoneal disease can be caused by a wide spectrum of pathologies. While peritoneal disease is usually caused by primary or secondary malignancies, benign diseases can occur and mimic malignancies. This article begins with an overview of peritoneal embryology and anatomy followed by a detailed description of the multimodality imaging appearance of peritoneal diseases. Common diseases include peritoneal carcinomatosis, pseudomyxoma peritonei, lymphomatosis, sarcomatosis, and tuberculous peritonitis. The uncommon diseases which cause peritoneal disease include desmoid fibromatosis, desmoplastic small round cell tumor, malignant mesothelioma, well-differentiated mesothelioma, multicystic mesothelioma, papillary serous carcinoma, leiomyomatosis, extramedullary hematopoiesis, inflammatory pseudotumor and amyloidosis. This manuscript will help the radiologist become familiar with the different peritoneal spaces, pathways of spread, multimodality imaging appearance and differential diagnoses of peritoneal diseases in order to report the essential information for surgeons and oncologists to plan treatment.

Objective: This article will describe and illustrate the relevant anatomy and surgical techniques used in pelvic reconstruction using regional pedicled thigh flaps, which is often necessary in oncologic surgeries. Examples of normal postoperative imaging and common complications that can accompany pelvic reconstruction with anterolateral, gracilis myocutaneous, and posterior thigh fasciocutaneous flaps will be provided., Conclusion: Pelvic reconstruction using regional pedicled thigh flaps is often needed with extirpative oncologic surgeries to eliminate dead space, provide pelvic organ support, restore form and function, and introduce vascularized tissue to promote wound healing. Radiologists need to be aware of the normal postoperative appearance of these flaps so that the flaps are not mistaken for residual or recurrent disease and so that residual or recurrent disease can be identified and treated.

The role of Positron Emission Tomography/Computed Tomography (PET/CT) in the evaluation of various gynecologic malignancies in light of current available data is presented and illustrated with imaging examples, pearls, and common pitfalls. 18F-fluorodeoxyglucose PET/CT is being increasingly used in management of gynecologic malignancy and has useful applications in cervical, ovarian, and endometrial carcinoma. Sensitivity and specificity are superior compared with conventional imaging. However, there are limitations of which the reporting physician should be aware. This article introduces the available evidence and discusses the role of PET/CT in various gynecologic malignancies and highlights imaging pearls and potential pitfalls., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objective: We sought to determine the incidence of venous tumor thrombus in nonfunctioning pancreatic neuroendocrine tumors., Materials and Methods: We reviewed CT images of patients with a diagnosis of nonfunctional pancreatic neuroendocrine tumors over a 4-year period. For patients who underwent surgery, changes to surgical plans related to the tumor thrombus were also recorded., Results: CT showed venous tumor thrombi in 29 of the 88 patients (33%; 95% CI, 23-44%). This CT finding was not accurately reported in 18 of the 29 patients (62%; 95% CI, 42-79%). Of the 39 patients who underwent surgery, venous tumor thrombi were detected in 11 patients (28%; 95% CI, 15-45%) and were confirmed by pathology. Microscopic venous tumor thrombi in 10 patients were not detected by CT. Pathologic results showed venous tumor thrombi in 21 of the 39 patients (54%; 95% CI, 37-70%) who underwent surgery. The surgical plan was significantly changed in two of the 11 patients with gross thrombi (18%; 95% CI, 2-52%) who underwent surgery. There was no change in the surgical plan for the 10 patients with microscopic tumor thrombi., Conclusion: The incidence of venous tumor thrombus detected by imaging was 33% in our study. This imaging finding was not accurately reported on the radiology report in 62% of the patients. In 18% of the patients with gross venous tumor thrombi, there was a significant alteration in the surgical plan. It is critical for the radiologist to be aware of the association of venous tumor thrombi in patients with nonfunctioning pancreatic neuroendocrine tumors and to report these findings.

Objective: To study the behavior of hypoattenuating liver lesions, deemed too small to characterize at baseline scanning with multidetector computed tomography (CT), in patients with rectal cancer., Methods: Retrospective review of locally advanced rectal cancer patients from a radiation oncology therapy database was conducted. Patients who presented before neoadjuvant chemoradiation without metastases at baseline CT and with follow-up scans for at least 1 year after therapy were evaluated. CT studies were reviewed for the presence and change in size of hypoattenuating liver lesions (<15 mm) at baseline and follow-up., Results: A total of 616 consecutive patients from the radiotherapy database were reviewed. Of these, 70 patients with a total of 163 hepatic lesions met the selection criteria. The mean patient age was 62.4 years (range, 26-85 years). All patients subsequently underwent surgery and adjuvant chemotherapy. The mean time of radiographic imaging from baseline CT to most recent surveillance CT was 3.3 years (range, 1.1-7.4 years). Two radiologists independently reviewed the CTs. The lesions were stable in 56 of 70 (80.0%, 95% confidence interval: 69%, 89%) patients. Of 163 lesions, 148 (90.8%) were stable, 8 (4.9%) regressed, and 7 (4.3%) progressed in size. No significant difference in results was found for patients stratified according to T-stage (P = 0.41) and N-stage (P > 0.99)., Conclusion: In patients with rectal cancer, majority of small hypoattenuating liver lesions remain stable and are treated as benign lesions, at multidetector CT follow-up of more than a year. Nevertheless, hepatic lesion stability during systemic therapy should still be interpreted with caution and closely followed for at least 1 year after completion of therapy.

Background: Evaluate the significance of coronary arteries calcifications detected using contrast-enhanced chest computed tomography (CECCT) scans., Methods: A total of 145 patients who underwent both CECCT and gated stress myocardial perfusion imaging (MPI) within 2 weeks were included. The chest CT scans were reviewed for the presence of coronary artery calcium (CAC) by 2 experienced blinded readers. The degree of calcifications seen in any visualized area of the major coronary arteries was graded on a scale of 1 to 3 (1 when 0 to 4 small scattered plaques were seen, 2 when 5 or more scattered plaques were seen, and 3 when diffuse contiguous calcification were seen). The grade of CAC was correlated with the presence of MPI abnormalities. Additionally, the locations of the MPI abnormality was correlated with the CAC grade in the culprit coronary artery., Results: Of 580 major coronary arteries evaluated, 79% had grade 1 CAC, 10% had grade 2, 11% had grade 3, and 1% were inevaluable. Of the 145 patients, 33 (23%) had abnormal MPI results. Twenty-three of the patients with abnormal MPI results (70%) had more than 4 calcified plaques (CAC grade of 2 or 3) in one or more of their coronary arteries, whereas 41 of 122 patients with normal MPI results (37%) had similar CAC grades (P=0.001). Seventeen of the 33 patients (52%) who had MPI defects also had significant CAC in the culprit coronary artery, 7 patients (21%) had significant CAC in a different coronary artery from the MPI defect territory, 8 patients (24%) had no significant CAC visualized, and in 1 patient a pacemaker wire interfered with CAC grading in the culprit coronary artery (RCA). The sensitivity, specificity, the positive, and negative predictive values of grade 2 or 3 CAC for an abnormal MPI results were 70%, 63%, 36%, and 88%, respectively. When a subgroup of patients above 60 years old with grade 3 CAC was reanalyzed, the sensitivity, specificity, the positive, and negative predictive values for an abnormal MPI results were 69%, 73%, 41%, and 90%, respectively., Conclusion: Multiple diffuse CAC as detected during the interpretation of CECCT scans in combination with advanced age is a significant finding that warrants further investigation for functionally significant CAD.