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.

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.

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.

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.

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.

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.

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.

Gray-scale and color Doppler sonographic features of the vaginal cuff and cervical remnant after hysterectomy.

OBJECTIVE: The purpose of this study was to define the sonographic characteristics of the vaginal cuff and cervical remnant after hysterectomy and to establish normal measurements of each after each type of surgery. MATERIALS AND METHODS: One hundred twenty-one women who had undergone hysterectomy (mean age, 51 years; range, 31-80 years) were studied using transabdominal or transvaginal sonography. Seventy-six patients were acquired retrospectively and 45 prospectively. Hysterectomy types included abdominal, 52% (63/121); supracervical, 17% (20/121); vaginal, 17% (20/121); and unknown, 15% (18/121). Two reviewers, who were blinded to clinical information, evaluated each cuff or remnant in consensus. Transabdominal anteroposterior, transvaginal anteroposterior, and transvaginal length measurements before and after transducer compression, and amount of color Doppler flow as shown by percentage of color pixels (n = 36 patients) were correlated with hysterectomy type and patient age. RESULTS: Supracervical cuffs were larger (p < 0.01) than abdominal and vaginal hysterectomy cuffs (transabdominal sonography anteroposterior, 2.8 vs 1.5 and 1.6 cm; transvaginal sonography anteroposterior, 3.3 vs 1.8 and 1.7 cm; and transvaginal length, 3.0 vs 2.1 and 1.9 cm). Anteroposterior measurements, but not length, decreased significantly with advancing age. Transvaginal length decreased with compression (mean, 0.84 cm; p < 0.0001). Color Doppler flow scores (minimum, 56% [20/36]; mild, 28% [10/36]; moderate, 14% [5/36]; and absent, 3% [1/36]) did not vary with age, time since surgery, or type of surgery. CONCLUSION: The remnant is larger in every dimension after supracervical hysterectomy compared with both abdominal and vaginal hysterectomy and commonly shows some color Doppler flow.

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.

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.

Role of computed tomography in guiding the management of peripheral bronchopleural fistula.

The present study was designed to elucidate whether demonstration of a peripheral bronchopleural fistula on CT correlated with the need for surgical management. We retrospectively identified 33 patients, 24 males and nine females, mean age 38 years, with clinical diagnosis of peripheral bronchopleural fistula and whose chest CT scans and medical charts were reviewed. Each chart was reviewed to identify the cause of the peripheral bronchopleural fistula and its treatment. Treatment decisions were categorized as surgical or conservative. Each chest CT was evaluated for the cause of peripheral bronchopleural fistula as follows: bulla(e), lung abscess/necrotizing pneumonia, neoplasms, peripheral bronchiectasis, and trauma. The peripheral bronchopleural fistula was classified as visible on CT if a distinct channel between the lung or a peripheral bronchus and the pleura was seen on the lung windows. We found that CT was useful in guiding surgery by identifying and localizing the cause of the peripheral bronchopleural fistula in the 55% (18/33) of patients who required surgery. The peripheral bronchopleural fistula or its probable cause was identified in 91% (30/33) as follows: bulla(e) (n = 12), lung abscess/necrotizing pneumonia (n = 11), peripheral bronchiectasis (n = 5), malignancy (n = 1), and posttraumatic pneumatocele (n = 1). The peripheral bronchopleural fistula was right-sided in 24, left-sided in nine, and was visible on CT in 36% (12/33). Among the patients with bullae, 58% (7/12) required surgery; however, the peripheral bronchopleural fistula was visible on CT in only 8% (1/12). Among the 21 patients without bulla(e), the peripheral bronchopleural fistula was visible on CT in 52% (11/21). When the fistula was visible in this subgroup, 73% (8/11) required surgery compared with 30% (3/10) in whom the fistula was not visible (p = NS; Fisher exact). In conclusion, CT was useful in guiding surgery by identifying and localizing the peripheral bronchopleural fistula or its probable cause. Peripheral bronchopleural fistulas caused by bulla(e) were less likely to be visible on CT (p < 0.05). Excluding patients with bulla(e), our data suggest a trend toward the need for surgical management for patients in whom the peripheral bronchopleural fistula was visible on CT.

Type II endoleak after endoaortic graft implantation: diagnosis with helical CT arteriography.

PURPOSE: To retrospectively assess endoleak shapes and locations within aneurysms to differentiate type II from type I and type III endoleaks. MATERIALS AND METHODS: The institutional review board granted an exemption for this HIPAA-compliant study; patient informed consent was not required. A retrospective review of arterial phase helical computed tomographic (CT) studies and medical records was performed for 39 patients (29 men, 10 women; age range, 60-89 years; mean, 78.5 years) who had an endoleak after endoaortic graft implantation for treatment of abdominal aortic aneurysm and who subsequently underwent angiography (n = 25), surgery (n = 8), or long-term follow-up (n = 6) to classify their endoleak into a specific type. At CT, endoleak shape (tubular or nontubular) and location (central or peripheral) were recorded. An endoleak was classified as type II if it contained a peripheral tubular component (PTC) near the aortic wall, with or without an identifiable feeding vessel. Endoleaks without these features were classified as type I or III. The Fisher exact test was used to assess associations between CT findings and endoleak type. RESULTS: There were 22 type II and 17 type I or III endoleaks. CT enabled correct identification of 22 (100%) of 22 type II endoleaks, all of which contained a PTC. Of 17 type I or III endoleaks, only two (12%) contained a PTC and were misclassified as type II endoleaks; the remaining 15 (88%) were correctly classified. Overall, CT enabled correct identification of endoleaks as type II or type I or III in 37 (95%) of 39 patients. PTCs were significantly more common (P < .001) in type II than in type I or III endoleaks, with a sensitivity, specificity, accuracy, negative predictive value, and positive predictive value of 100%, 88.2%, 94.9%, 100%, and 91.7%, respectively. CONCLUSION: A PTC is a statistically significant predictor of type II endoleak in most patients.

Sonographic comparison of the tubal ring of ectopic pregnancy with the corpus luteum.

OBJECTIVE: Pregnant patients without a sonographically visible intrauterine pregnancy and with a thick-walled cystic adnexal structure present a dilemma. This study compared the utility of various sonographic features in differentiating between the tubal ring of ectopic pregnancy and the corpus luteum. METHODS: Retrospective review of first-trimester transvaginal sonograms revealed a cystic adnexal structure in 79 women. Each structure was evaluated for 6 specific sonographic characteristics: echogenicity of its wall compared with that of the ovary and endometrium, wall thickness in 2 planes, color Doppler flow distribution and percentage of wall circumference, and internal texture. RESULTS: Forty-one (52%) of the 79 women had ectopic pregnancies, and 38 (48%) had corpora lutea. Eleven (32%) of 35 ectopic walls were more echogenic than the endometrium, compared with none of the corpora lutea. A cyst wall less echogenic than the endometrium was more likely in corpora lutea (84% versus 31%; P < .0001). More than twice as many ectopic rinds were more echogenic than ovarian tissue compared with corpora lutea (76% versus 34%; P < .0001). The only predictive internal texture feature was a clear pattern, which was more common in the corpora lutea (P < .01, Fisher exact test). There was no significant difference in mural flow distribution or extent between the 2 groups. CONCLUSIONS: Ancillary sonographic signs to distinguish between an ectopic pregnancy and a corpus luteum include decreased wall echogenicity compared with the endometrium and an anechoic texture, which suggests a corpus luteum.

Detection of endoleaks after endovascular repair of abdominal aortic aneurysm: value of unenhanced and delayed helical CT acquisitions.

PURPOSE: To assess unenhanced and delayed phase computed tomographic (CT) images combined with arterial phase images for detecting endoleaks after endovascular treatment for abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: CT scans were retrospectively evaluated for the presence of endoleaks after endovascular treatment of AAAs in 33 patients with endoleak (positive group) and 40 patients without evidence of endoleak or aneurysm enlargement (negative group). All patients underwent unenhanced and biphasic contrast material-enhanced CT. The CT scans were reviewed in the following combinations: (a) arterial phase and unenhanced scans (uniphasic/unenhanced set), (b) arterial and delayed phase scans only (biphasic set), and (c) arterial and delayed phase scans with unenhanced scans (complete set). Each set was reviewed by two radiologists blinded to the diagnosis of endoleak. Findings were recorded as positive, negative, or indeterminate for endoleak. RESULTS: Within the positive group, endoleaks were diagnosed with the uniphasic/unenhanced, biphasic, and complete image sets in 30 (91%), 32 (97%), and 33 (100%) patients, respectively. With the uniphasic/unenhanced set, three (9%) endoleaks (seen only on delayed phase images) were missed. With the biphasic set, one (3%) endoleak was interpreted as indeterminate. Within the negative group, uniphasic/unenhanced, biphasic, and complete image sets were negative for endoleaks in 100%, 80%, and 100% of patients, respectively. With the biphasic set, results were indeterminate in 20% of cases. CONCLUSION: A delayed CT acquisition enables detection of additional endoleaks, while an unenhanced acquisition helps eliminate indeterminate results. Thus, both acquisitions contribute to accurate diagnosis of endoleaks when combined with an arterial phase acquisition.