When Aunt Minnie turns out to be a Zebra: distal bile duct adenomyoma stimulating pancreas head tumor.

A 55-year-old female patient with a history of ethyl and nicotine abuse presented with chronic diarrhoea, significant weight loss and abnormal liver tests. Ultrasound examination revealed dilatation of the bile ducts and computed tomography scan with IV contrast further established simultaneous dilatation of the common bile duct and pancreatic duct (double duct sign). The dilatation abruptly stopped at the level of the pancreatic head which demonstrated a small irregular hypovascular zone (1.2 cm), suspected for malignancy. The following week, a radical pancreaticoduodenectomy was performed. Anatomopathological analysis revealed an adenomyoma (12 mm) located distal to the common bile duct, without arguments for malignancy.

Don't burn the blanket to kill a flea: a case of intra-abdominal desmoid fibromatosis.

A 39-year-old woman presented to the Emergency Department with dysuria and persistent abdominal pain for several weeks. The pain increased with palpation. Physical examination was otherwise normal. Computerized tomography (CT) scan revealed a round structure of unknown origin against the caecum and terminal ilium suspect for a GIST tumor and a fluid-filled right uterine tube suggestive of pyosalpinx. The following day a laparoscopic surgery with removal of the pyosalpinx and complete right hemi-colon including the suspected lesion was performed and biopsies of the surrounding peritoneum, meso and ileum were taken. Immunohistochemical tests (CD117/DOG1) and molecular analysis (KIT/PDGFRA) ruled out GIST. SMA and desmin were also negative. ß-catenin along with next generation sequencing which revealed a likely pathogenic mutation in exon 3 of the CTNNB1 gene, suggested a diagnosis of desmoid-type fibromatosis (DF). Biopsies of the lymph nodes were negative.

Diagnostic Performance of Chest CT for SARS-CoV-2 Infection in Individuals with or without COVID-19 Symptoms.

Background The use of chest CT for coronavirus disease 2019 (COVID-19) diagnosis or triage in health care settings with limited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) capacity is controversial. COVID-19 Reporting and Data System (CO-RADS) categorization of the level of COVID-19 suspicion might improve diagnostic performance. Purpose To investigate the value of chest CT with CO-RADS classification to screen for asymptomatic SARS-CoV-2 infections and to determine its diagnostic performance in individuals with COVID-19 symptoms during the exponential phase of viral spread. Materials and Methods In this secondary analysis of a prospective trial, from March 2020 to April 2020, parallel SARS-CoV-2 PCR and CT with categorization of COVID-19 suspicion was performed with CO-RADS for individuals with COVID-19 symptoms and control participants without COVID-19 symptoms admitted to the hospital for medical emergencies unrelated to COVID-19. CT with CO-RADS was categorized on a five-point scale from 1 (very low suspicion) to 5 (very high suspicion). Area under the receiver operating curve (AUC) was calculated in symptomatic versus asymptomatic individuals to predict positive SARS-CoV-2 PCR, and likelihood ratios for each CO-RADS score were used for rational selection of diagnostic thresholds. Results A total of 859 individuals (median age, 70 years; interquartile range, 52-81 years; 443 men) with COVID-19 symptoms and 1138 control participants (median age, 68 years; interquartile range, 52-81 years; 588 men) were evaluated. CT with CO-RADS had good diagnostic performance (P < .001) in both symptomatic (AUC, 0.89) and asymptomatic (AUC, 0.70) individuals. In symptomatic individuals (42% PCR positive), CO-RADS 3 or greater detected positive PCR with high sensitivity (89%, 319 of 358) and specificity of 73%. In asymptomatic individuals (5% PCR positive), a CO-RADS score of 3 or greater detected SARS-CoV-2 infection with low sensitivity (45%, 27 of 60) but high specificity (89%). Conclusion CT with Coronavirus Disease 2019 Reporting and Data System (CO-RADS) had good diagnostic performance in symptomatic individuals, supporting its application for triage. Sensitivity in asymptomatic individuals was insufficient to justify its use as a first-line screening approach. Incidental detection of CO-RADS 3 or greater in asymptomatic individuals should trigger testing for respiratory pathogens. © RSNA, 2020 Online supplemental material is available for this article.

Endovascular management of an isolated dissection of the celiac artery following a blunt deceleration-type trauma.

A 29-year-old, otherwise healthy male was brought to the emergency department after suffering an injury from falling from the roof of his house. Whole-body computed tomography (CT) showed a small ostial dissection of the celiac artery (CA) associated with a pseudoaneurysm, thrombosis, and retroperitoneal periaortic hematoma. The celiac trunk was otherwise normal with good distal patency and no signs of intestinal ischemia. The patient was successfully managed via an endovascular approach with the placement of a covered stent in the CA.

CT colonography: size reduction of submerged colorectal polyps due to electronic cleansing and CT-window settings.

OBJECTIVES: To assess whether electronic cleansing (EC) of tagged residue and different computed tomography (CT) windows influence the size of colorectal polyps in CT colonography (CTC). METHODS: A database of 894 colonoscopy-validated CTC datasets of a low-prevalence cohort was retrospectively reviewed to identify patients with polyps ≥6 mm that were entirely submerged in tagged residue. Ten radiologists independently measured the largest diameter of each polyp, two-dimensionally, before and after EC in colon, bone, and soft-tissue-windows, in randomised order. Differences in size and polyp count before and after EC were calculated for size categories ≥6 mm and ≥10 mm. Statistical testing involved 95% confidence interval, intraclass correlation and mixed-model ANOVA. RESULTS: Thirty-seven patients with 48 polyps were included. Mean polyp size before EC was 9.8 mm in colon, 9.9 mm in bone and 8.2 mm in soft-tissue windows. After EC, the mean polyp size decreased significantly to 9.4 mm in colon, 9.1 mm in bone and 7.1 mm in soft-tissue windows. Compared to unsubtracted colon windows, EC, performed in colon, bone and soft-tissue windows, led to a shift of 6 (12,5%), 10 (20.8%) and 25 (52.1%) polyps ≥6 mm into the next smaller size category, thus affecting patient risk stratification. CONCLUSIONS: EC and narrow CT windows significantly reduce the size of polyps submerged in tagged residue. Polyp measurements should be performed in unsubtracted colon windows. KEY POINTS: • EC significantly reduces the size of polyps submerged in tagged residue. • Abdominal CT-window settings significantly underestimate 2D sizes of submerged polyps. • Size reduction in EC is significantly greater in narrow than wide windows. • Underestimation of polyp size due to EC may lead to inadequate treatment. • Polyp measurements should be performed in unsubtracted images using a colon window.

Image quality improvement in submillisievert computed tomographic colonography using a fast 3-dimensional noise reduction method.

OBJECTIVE: The objective of this study was to evaluate the image quality in submillisievert computed tomographic colonography (CTC) images using a structure preserving diffusion denoising method. METHODS: Image quality was compared before and after denoising in 31 patients. One hundred twenty-kilovolt, 30-mAs prone CTC scans were used as reference and compared with submillisievert 140-kV, 10-mAs supine scans. Two readers assessed 2-dimensional and endoluminal image quality. The image noise and the signal-to-noise ratio were measured. RESULTS: After denoising, image quality scores improved in both supine series and prone series (P < 0.0001), with the submillisievert denoised images being equal to or better than the native prone reference images. In both the supine images and the prone images, the noise was reduced by a factor of 2 and the signal-to-noise ratio was significantly higher (P < 0.001). The signal-to-noise ratio in the denoised submillisievert images was higher than those in the native prone images (P < 0.001). CONCLUSIONS: The structure preserving diffusion denoising method preserves the image quality in submillisievert CTC images compared with the native 30-mAs reference images.

Chronic diverticulitis vs. colorectal cancer: findings on CT colonography.

PURPOSE: The purpose of this update article is to evaluate findings on CT colonography in patients with chronic diverticulitis and to compare the findings in patients with colorectal carcinoma. MATERIALS AND METHODS: Different morphological criteria retrieved from a literature review were retrospectively analyzed in a series of 13 patients with proven chronic diverticulitis. The findings were compared with a series of 10 patients with colorectal carcinoma. RESULTS: Overall, the findings in chronic diverticulitis resemble the findings in acute diverticulitis. The advantage of virtual CT colonography in differentiating both entities relies in the combination of morphological features previously described on axial computed tomography and double contrast barium enema. The single strongest morphological feature pointing towards the diagnosis of chronic diverticulitis is the presence of diverticula in the affected segment. In the presence of diverticula in the affected segment, a long segment (≥10 cm), thick fascia sign without adenopathies, mild bowel wall thickening, tapered margins, and distorted but preserved mucosal folds are likely to further improve accuracy of diagnosing chronic diverticulitis. CONCLUSION: The single strongest morphological sign to differentiate chronic diverticulitis from colorectal cancer is the presence of diverticula in the affected segment.

Inflammatory Pseudotumor of the Mesentery.

Teaching point: An inflammatory pseudotumor can occur almost everywhere in the body and has nonspecific imaging findings.

Bilateral pulmonary sequestration complicated with a bibasal pneumonia in an adult patient.

Pulmonary sequestrations (PS) are rare congenital pulmonary malformations, characterized by non-functioning and dysplastic pulmonary tissue, without a normal connection to the tracheobronchial tree and supplied by the systemic arterial circulation. PS typically occur in the lower lobes and the radiologist should consider the possibility of a PS in a patient with persistent or recurrent pneumonia in the lower lobes, especially in children. We hereby present a rare case of bilateral intralobar PS complicated with bilateral pneumonia, in a previously healthy 37-year-old male patient, who was referred to the emergency department by his general practitioner because of persisting dyspnea and fever. The hospital stay was complicated with central nervous aspergillosis due to septic emboli.

Serum 25(OH)D Level on Hospital Admission Associated With COVID-19 Stage and Mortality.

OBJECTIVES: Vitamin D deficiency was previously correlated with incidence and severity of coronavirus disease 2019 (COVID-19). We investigated the association between serum 25-hydroxyvitamin D (25(OH)D) level on admission and radiologic stage and outcome of COVID-19 pneumonia. METHODS: A retrospective observational trial was done on 186 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals hospitalized from March 1, 2020, to April 7, 2020, with combined chest computed tomography (CT) and 25(OH)D measurement on admission. Multivariate regression analysis was performed to study if vitamin D deficiency (25(OH)D <20 ng/mL) correlates with survival independently of confounding comorbidities. RESULTS: Of the patients with COVID-19, 59% were vitamin D deficient on admission: 47% of females and 67% of males. In particular, male patients with COVID-19 showed progressively lower 25(OH)D with advancing radiologic stage, with deficiency rates increasing from 55% in stage 1 to 74% in stage 3. Vitamin D deficiency on admission was not confounded by age, ethnicity, chronic lung disease, coronary artery disease/hypertension, or diabetes and was associated with mortality (odds ratio [OR], 3.87; 95% confidence interval [CI], 1.30-11.55), independent of age (OR, 1.09; 95% CI, 1.03-1.14), chronic lung disease (OR, 3.61; 95% CI, 1.18-11.09), and extent of lung damage expressed by chest CT severity score (OR, 1.12; 95% CI, 1.01-1.25). CONCLUSIONS: Low 25(OH)D levels on admission are associated with COVID-19 disease stage and mortality.

Electronic cleansing of tagged residue in CT colonography: what radiologists need to know.

CT colonography (CTC) is the radiological examination of choice for the diagnosis of colorectal neoplasia. Faecal tagging is considered a mandatory part of bowel preparation. However, the colonic mucosa, obscured by tagged residue, is not accessible to endoluminal 3D views and requires time-consuming 2D evaluation. Electronic cleansing (EC) software algorithms can overcome this limitation by digitally subtracting tagged residue from the colonic lumen. Ideally, this enables a seamless 3D endoluminal evaluation. Despite this benefit, EC is a potential source of a wide range of artefacts. Accurate EC requires proper CTC examination technique and faecal tagging. The digital subtraction process has been shown to affect the relevant morphological features of both colonic anatomy and colonic lesions, if submerged under faecal residue. This article summarises the potential effects of EC on CTC imaging, the consequences for reporting and patient management, and strategies to avoid pitfalls. Furthermore, potentially negative effects on clinical reporting and patient management are shown, and problem-solving techniques, as well as recommendations for the appropriate use of EC techniques, are presented. Radiologists using EC should be familiar with EC-related effects on polyp size and also with correct measurement techniques.

CT colonography polyp matching: differences between experienced readers.

The purpose of this study was to investigate if experienced readers differ when matching polyps shown by both CT colonography (CTC) and optical colonoscopy (OC) and to explore the reasons for discrepancy. Twenty-eight CTC cases with corresponding OC were presented to eight experienced CTC readers. Cases represented a broad spectrum of findings, not completely fulfilling typical matching criteria. In 21 cases there was a single polyp on CTC and OC; in seven there were multiple polyps. Agreement between readers for matching was analyzed. For the 21 single-polyp cases, the number of correct matches per reader varied from 13 to 19. Almost complete agreement between readers was observed in 15 cases (71%), but substantial discrepancy was found for the remaining six (29%) probably due to large perceived differences in polyp size between CT and OC. Readers were able to match between 27 (71%) and 35 (92%) of the 38 CTC detected polyps in the seven cases with multiple polyps. Experienced CTC readers agree to a considerable extent when matching polyps between CTC and subsequent OC, but non-negligible disagreement exists.

CT colonography: visualization methods, interpretation, and pitfalls.

Virtual colonoscopy interpretation is improving rapidly with the development of efficient software using two-dimensional, three-dimensional (3D) endoluminal, and 3D novel views such as those that seem to cut the colon open and lay it flat for interpretation. Comparison of these various views, comparisons of supine and prone positioning, and comparisons of lung and soft tissue windows aid in the recognition of various pitfalls of interpretation.