Abdominopelvic CT in COVID-19 patients with abdominal complaints including both waves and controls: reader agreement and overcalls after consensus review.

BACKGROUND: Since many COVID-19 publications lack consensus reviews or controls, interpretive accuracy is unclear; abdominal processes unique or infrequent during the pandemic remain unknown. The incidence and nature of CT findings accounting for abdominal complaints in COVID patients, reader agreement and overcalling will be determined. METHODS: A retrospective study was performed on COVID patients with abdominal complaints from 3/15/2020-5/31/2020 and 11/1/2020-4/15/2021 including matched controls. Reviewers blinded to initial reads interpreted abdominopelvic CT exams, with discordant cases resolved in consensus. Reader agreement was measured by Cohen's Kappa, differences between cohorts by permutation tests and factors affecting false positive/negative rates by Fisher's Exact Test and logistic regression. RESULTS: 116 first wave (average age 65 years [±15.3], 63 [54%] women) and 194 second wave COVID cases (average age 64 years [±16.3], 103 [53%] women) including 116 wave 1 and 194 wave 2 prepandemic controls were included. Concordance was lower among COVID cases than controls (Cohen's Kappa of 0.58 vs. 0.82 [p ≤ 0.001]) and among wave 1 than wave 2 cases (Cohen's Kappa of 0.45 vs. 0.66 [p = 0.052]). With true positives defined as consensus between the initial reader and study reader, false positive rates were higher among COVID cases than controls (OR = 0.42, p = 0.003) and for initial than study reader (OR = 0.36, p ≤ 0.001), but lower in wave 2 than 1 (OR = 0.5, p = 0.028). CONCLUSION: Greater reader disagreement occurred during COVID than prepandemic with no reader bias as both initial and study readers called more false positives among COVID cases than controls. More overcalling occurred during COVID with colitis and cystitis most common.

Imaging features of anorectal proctitis in monkeypox infection.

The monkeypox outbreak of 2022 saw the first community-sustained transmission of the monkeypox virus outside of Africa, and rapidly developed into multi-country spread. A common presenting sign of monkeypox infection during this outbreak has been rectal pain due to proctitis. Proctitis with large hypoattenuated anorectal ulcers on CT scan should invoke consideration for monkeypox infection in young homosexual or bisexual men with associated skin eruptions.

Colonic lipomas revisited on CT colonography.

PURPOSE: CT colonography (CTC) is growing in its utilization as a nationally approved colorectal cancer screening test. After colonic polyps, lipomas are the second most common colonic lesions and their accurate and rapid recognition are important. METHODS: This retrospective Institutional Review Board approved study was performed at two large academic university-based institutions. 1044 patients underwent CTC at Institution A from 2010 to 2018 and 1094 patients underwent CTC at Institution B from 2003 to 2015. All CTC examinations with at least one colonic lipoma in their report were evaluated by a fellowship-trained abdominal imaging radiologist. 47 CTC examinations containing 59 colonic lipomas were detected and included. Segmental location, sessile versus pedunculated morphology, multiplicity, average attenuation, and largest lesion diameter were evaluated. A review of the current literature on colonic lipomas is entailed. RESULTS: The overall incidence of colonic lipoma was 2.2% in women and 2.3% in men. Mean age for detection of colonic lipomas on CTC was 66.9 years. Segmental locations of colonic lipomas include ascending colon (39%), transverse colon (19%), ileocecal valve (12%), cecum (12%), descending colon (10%), and rectosigmoid (8%). 9% of colonic lipomas were multiple, 42% were pedunculated, and 58% were sessile. The mean (range) size of detected lipomas was 19 (6-59) mm. The mean (range) attenuation was - 132 (- 41 to - 258) HU. CONCLUSION: Most colonic lipomas are located in the ascending colon. Although they are typically solitary, just under 10% are multiple, and although they are most often sessile, slightly under half are pedunculated mimicking polyps. CTC detects smaller lipomas than optical colonoscopy.

CT features of acquired cystic kidney disease-associated renal cell carcinoma.

PURPOSE: Acquired cystic kidney disease-associated renal cell carcinoma (ACKD-RCC) is a relatively recently described entity with scarce literature describing its imaging appearance (1, 2). The purpose of this study was to determine typical and potentially unique features of ACKD-RCC on CT scan that could aid lesion identification. MATERIALS AND METHODS: A retrospective review of the CT scans of 24 patients with 29 histologically proven ACKD-RCC lesions was performed. Imaging features were recorded based on consensus readings of two radiologists. RESULTS: Tumors ranged in size from 1.2 to 5 cm. Nineteen lesions were right-sided and 10 left-sided. Nineteen lesions were exophytic. One patient had bilateral lesions and three patients had multiple lesions in the same kidney. All lesions had well-defined margins with 21 round, 7 lobulated and 1 crescentic in shape. On non-enhanced exam 4 lesions were hypodense, 16 iso-dense and 9 hyperdense; 5 had gross calcifications. Twenty two patients had contrast-enhanced CT exams, with 13 lesions demonstrating homogeneous enhancement (solid pattern) and 14 having inhomogeneous enhancement (cystic or mixed solid and cystic pattern). Only 1 patient had metastatic disease. Eight patients had a history of renal transplants. CONCLUSION: ACKD-RCCs are well-defined lesions of variable size that are almost always rounded and most often exophytic. They occasionally have calcifications and are not uncommonly hyperdense on non-enhanced exam. They are most often iso-dense on non-enhanced exam and can be solid, cystic or mixed in attenuation on enhanced exam.

Review of COVID-19, part 2: Musculoskeletal and neuroimaging manifestations including vascular involvement of the aorta and extremities.

The coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world resulting in severe morbidity, mortality and economic hardship, altering the landscape of healthcare forever. Its devastating and most frequent thoracic and cardiac manifestations have been well reported since the start of the pandemic. Its extra-thoracic manifestations are myriad and understanding them is critical in diagnosis and disease management. The role of radiology is growing in the second wave and second year of the pandemic as the multiorgan manifestations of COVID-19 continue to unfold. Musculoskeletal, neurologic and vascular disease processes account for a significant number of COVID-19 complications and understanding their frequency, clinical sequelae and imaging manifestations is vital in guiding management and improving overall survival. The authors aim to provide a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19. In Part I, abdominal manifestations of COVID-19 in adults and multisystem inflammatory syndrome in children will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

Review of COVID-19, part 1: Abdominal manifestations in adults and multisystem inflammatory syndrome in children.

The coronavirus disease 2019 (COVID -19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world, resulting in severe morbidity, mortality and economic hardship, and altering the landscape of healthcare forever. Although primarily a pulmonary illness, it can affect multiple organ systems throughout the body, sometimes with devastating complications and long-term sequelae. As we move into the second year of this pandemic, a better understanding of the pathophysiology of the virus and the varied imaging findings of COVID-19 in the involved organs is crucial to better manage this complex multi-organ disease and to help improve overall survival. This manuscript provides a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19 with the exception of unique cardiothoracic features associated with multisystem inflammatory syndrome in children (MIS-C). In Part I, extra-thoracic manifestations of COVID-19 in the abdomen in adults and features of MIS-C will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

CT Colonography: Improving Interpretive Skill by Avoiding Pitfalls.

An earlier incorrect version of this article appeared online. This article was corrected on December 20, 2019.

Colostomy on CT and fluoroscopy: What the radiologist needs to know.

Colostomies are commonly created in conjunction with colorectal surgery performed for both malignant and benign indications. Familiarity with the different types of colostomies and their normal imaging appearance will improve radiologic detection and characterization of colostomy complications. The radiologist plays a large role in assessment of colostomy patients either via fluoroscopic technique or multidetector computed tomography (CT) in order to help identify ostomy complications or to aid the surgeon prior to colostomy reversal. In this article, we will review: (1) the types of colostomies and indications for their creation; (2) the proper radiographic technique of ostomy evaluation; and (3) the potential complications of colostomies and their imaging manifestations.

Comparison of extracolonic findings and clinical outcomes in a screening and diagnostic CT colonography population.

PURPOSE: To compare the distribution of extracolonic findings and clinical outcomes between screening and diagnostic CT colonography (CTC) populations. METHODS: 388 consecutive patients (369 men, 19 women; mean ± SD age 67.8 ± 10 years) who underwent first-time CTC (4/2011-4/2017) at a Veteran's Affairs Medical Center were divided into screening (asymptomatic) or diagnostic (symptomatic) cohorts based on CTC indication. CTC reporting and data system E-scores for extracolonic findings were retrospectively assigned based on prospective CTC radiologic reports. Multinomial logistic regression was used to examine the association between E-scores and CTC indication. Electronic medical records of all patients with E3 or E4 scores were reviewed (median follow-up 2.8 years) to determine clinical outcomes. RESULTS: 68% (262/388) underwent screening and 32% (126/388) diagnostic CTC. 7.2% (28/388) had extracolonic findings considered potentially significant (E4), 4.4% (17/388) had indeterminate but likely unimportant findings (E3), and 88.4% (347/388) had normal or unimportant findings (E1 or E2). E-scores were not significantly different between screening and diagnostic CTC when adjusted for age, gender, and prior imaging (p = 0.44). 4.6% (12/262) of patients with E3/E4 findings in the screening cohort demonstrated clinically significant outcomes, compared with 4.0% (5/126) in the diagnostic cohort, including a total of three extracolonic malignancies (0.8%) and three abdominal aortic aneurysms (0.8%). 4.6% (18/388) underwent follow-up imaging studies to confirm a benign outcome after detection of a category E3/E4 finding. CONCLUSIONS: The distribution of extracolonic findings and clinical outcomes were not statistically significantly different between screening and diagnostic CTC populations.

Improving diagnosis of atraumatic splenic lesions, part II: benign neoplasms/nonneoplastic mass-like lesions.

Focal atraumatic splenic lesions often pose a diagnostic challenge on cross-sectional imaging. They can be categorized based on etiology as nonneoplastic, benign neoplastic (discussed in Part II), and malignant neoplastic lesions or on prevalence as common, uncommon, and rare lesions. Familiarity with pertinent clinical parameters, etiology, pathology, prevalence and ancillary features such as splenomegaly, concomitant hepatic involvement, and extrasplenic findings, in addition to knowledge of imaging spectra of the lesions, can improve diagnostic confidence. Consideration of these factors together can arm the radiologist with the necessary tools to render a more confident diagnosis and, thus, better aid management.

Hollow organ abdominal ischemia, part II: clinical features, etiology, imaging findings and management.

Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and almost always requires urgent treatment. Despite different risk factors and anatomic differences, ischemia is commonly due to low flow states but can also be due to arterial and venous occlusion. Radiologic diagnosis is critical as many present with nonspecific symptoms. Contrast-enhanced computed tomography (CT) is the modality of choice. Magnetic resonance imaging (MRI) is preferred in suspected appendicitis in pregnant patients and is superior in biliary necrosis. This article provides a pictorial review of the CT/MRI features of hollow abdominal organ ischemia while highlighting key clinical features, pathogenesis, and management.

Improving diagnosis of atraumatic splenic lesions, part I: nonneoplastic lesions.

Focal atraumatic splenic lesions often pose a diagnostic challenge on cross-sectional imaging. They can be categorized based on etiology as nonneoplastic (reviewed in Part I), benign neoplastic, and malignant neoplastic lesions. Lesions can also be characterized based on prevalence as common, uncommon, and rare. Familiarity with pertinent clinical parameters, etiology, pathology, prevalence, and ancillary features such as splenomegaly, concomitant hepatic involvement, and extrasplenic findings, in addition to knowledge of imaging spectra of these lesions, can improve diagnostic confidence. Since the nonneoplastic lesions are usually easily recognized, it is critical that the radiologist identifies them avoiding unnecessary work up.

Solid organ abdominal ischemia, part I: clinical features, etiology, imaging findings, and management.

Solid organ abdominal ischemia commonly presents with acute pain prompting radiologic evaluation and often requires urgent treatment. Despite different risk factors and anatomic differences, most solid organ ischemia is due to arterial or venous occlusion and, less frequently, a low-flow state. Radiologic diagnosis is critical, as clinical presentations are often nonspecific. Contrast-enhanced computed tomography (CT) is the modality of choice (except in adnexal torsion) with magnetic resonance imaging (MRI) useful in equivocal cases or follow-up of ischemic disease. This article will provide a pictorial review of the CT and MRI features of solid abdominal organ ischemia while highlighting key clinical features, etiology, and management.

Improving diagnosis of atraumatic splenic lesions, Part III: malignant lesions.

Focal atraumatic splenic lesions often pose a diagnostic challenge on cross-sectional imaging. They can be categorized based on etiology, as nonneoplastic, benign neoplastic, and malignant neoplastic (discussed in Part III) lesions, or on prevalence, as common, uncommon, and rare lesions. Familiarity with pertinent clinical parameters, etiology, pathology, prevalence, and ancillary features such as splenomegaly, concomitant hepatic involvement, and extrasplenic findings, in addition to knowledge of imaging spectra of the lesions, can improve diagnostic confidence. Consideration of these factors together can arm the radiologist with the necessary tools to render a more confident diagnosis and thus better aid management.

Pearls and pitfalls in first-trimester obstetric sonography.

Ultrasound is the primary imaging modality used in the evaluation of first-trimester vaginal bleeding and pelvic pain. This article will summarize the ultrasound findings in normal first-trimester pregnancy, failed pregnancy, ectopic pregnancy, subchorionic hemorrhage, retained products of conception, and gestational trophoblastic disease. Mastery of the spectrum of sonographic findings in the normal and abnormal first-trimester pregnancy allows the radiologist to make accurate diagnoses and helps to appropriately guide patient management.

Adrenal cysts: natural history by long-term imaging follow-up.

OBJECTIVE: The purpose of this article is to determine the natural history of adrenal cysts on the basis of long-term imaging follow-up. MATERIALS AND METHODS: This retrospective study included patients with adrenal cysts who had at least 12 months of imaging follow-up (1993-2010). Medical records were reviewed. Two radiologists reviewed imaging examinations in consensus and recorded wall thickness (thin, ≤ 3 mm; thick, > 3 mm), septations, and calcification. CT attenuation value, MRI signal intensity, the presence or absence of enhancement, and typical sonographic features were used to confirm fluid content of the lesions. Cyst wall enhancement was recorded (thin, ≤ 3 mm and smooth; thick, > 3 mm). Cyst diameter on the initial and most remote follow-up examinations was compared. The Wilcoxon matched-pairs signed rank test was applied to assess statistically significant differences in size and CT attenuation on follow-up examinations. RESULTS: Twenty patients with unilateral adrenal cysts (seven male and 13 female patients; mean age, 44 years; range, 10-75 years) had a mean imaging follow-up period of 64 months (range, 12-198 months). CT, MRI, and ultrasound examinations were obtained in 19, 11, and 13 patients, respectively. Cysts were diagnosed by lack of enhancement on CT or MRI in 12 patients, typical sonographic features in three patients, and combination of CT and sonographic or MRI features in five patients. Signal intensities typical for fluid were found on all MRI examinations, attenuations of less than 20 HU on 17 of 19 (89%) CT examinations, and features of either simple or mildly complicated cysts on all sonograms. Thin walls, wall calcifications, and thin septations were found in 20 (100%), 12 (60%), and four (20%) lesions, respectively. During the follow-up of 20 lesions, the median cyst diameter increased by 26.0% (interquartile range, 6.8-68.4%) in 12 (60%) patients, decreased by 32.9% (interquartile range, 7.1-42.8%) in six (30%) patients, and was unchanged in two (10%) patients. The median baseline CT attenuation values did not significantly change on follow-up CT examinations (p = 0.72). No patient developed a complication of adrenal cyst. Four patients had histologically confirmed benign adrenal cysts. CONCLUSION: Interval enlargement of an adrenal cyst is frequent and as an isolated finding does not indicate malignancy or presence of a complication. However, some adrenal cysts may decrease or remain stable in size over time.

Hepatic enhancement during the hepatobiliary phase after gadoxetate disodium administration in patients with chronic liver disease: the role of laboratory factors.

PURPOSE: To identify factors influencing hepatobiliary phase (HBP) hepatic enhancement on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD). MATERIALS AND METHODS: We retrospectively reviewed abdominal gadoxetate disodium-enhanced MRIs and medical records of patients with (n=97) and without (n=48) CLD. CLD subgroups were formed based on normal/abnormal components of liver function tests (LFTs). Hepatic enhancement coefficients (HEKs) were calculated on MRI, and compared with LFTs and Model for End-stage Liver Disease (MELD) scores. RESULTS: The mean HEK was significantly lower (P<0.0008) in the CLD than control group. The mean HEK was similar to controls in the subgroup with all normal LFTs (P=0.09) and subgroup with normal direct bilirubin (DB) (p=0.09), while it was significantly reduced (P<0.0001) in the subgroup with elevated DB. For all other LFT components, regardless of normal or abnormal values, there was a significant reduction in the mean HEKs versus controls (all P values<0.01). There was a highly negative correlation between the mean HEKs in CLD subgroups and number of abnormal LFTs (r=-0.93) and MELD scores (r=-0.89). CONCLUSION: HBP hepatic enhancement in CLD patients is similar to those with no CLD as long as direct bilirubin remains normal. Higher MELD scores and higher number of abnormal LFT components are associated with reduced hepatic enhancement.

Efficacy of contrast-enhanced CT in assessing the endometrium.

OBJECTIVE: The purpose of our study was to determine the efficacy of contrast-enhanced CT in detecting a thickened endometrium. We used transvaginal sonography as the reference standard. MATERIALS AND METHODS: Between March 2005 and January 2007, data from 259 patients (mean age, 47 years; age range, 18-90 years) who underwent transvaginal sonography and contrast-enhanced CT of the pelvis were analyzed retrospectively. The endometrium was quantitatively measured in millimeters on sonography. On CT it was qualitatively categorized as normal, thickened, indeterminate, or not visualized and compared with the sonography findings and original radiology reports. When the endometrium was indeterminate (thickened or triangular in shape on axial images), sagittal reconstructions were performed for final categorization. Two reviewers evaluated the CT scans and sonograms jointly with differences resolved by consensus. Kappa, Wilcoxon's rank sum test, and intraclass correlation statistics were derived. RESULTS: The overall sensitivity and specificity of CT in detecting the thickened endometrium was 53.1% and 93.5%, respectively, relative to transvaginal sonography. The positive and negative predictive values were 66.7% and 89.1%, respectively. Kappa, the statistical measure of agreement between CT and sonography data, was 0.5049. All cases of a triangular endometrium were normal in size on sagittal reconstruction images. CONCLUSION: Routine pelvic CT correctly identifies a normal endometrium in most patients. Sagittal reconstruction images are helpful to further evaluate the endometrium on CT in cases with a prominent or triangular endometrium because these are often related to uterine version. CT is relatively insensitive in detecting the thickened endometrium but better able to identify gross rather than subtle thickening, which must be further characterized by transvaginal sonography.