A Systematic Review of Abdominal Imaging Findings in COVID-19 Patients

<b><i>Objective:</i></b> The objective of this systematic review was to evaluate key imaging manifestations of COVID-19 on abdominal imaging by utilizing a comprehensive review of the published literature. <b><i>Method:</i></b> A systematic literature search from PubMed, Google Scholar, and Scopus was performed for studies mentioning abdominal imaging findings in COVID-19 patients. Studies published from inception to 15 March 2021 were included. <b><i>Results:</i></b> A total of 116 studies comprising 1,198 patients were included. Abdominal pain was the most common indication for abdominal imaging in 50.2% of the patients. No abnormality was seen in 48.1% of abdominopelvic computed tomography scans. Segmental bowel wall thickening (14.7%) was the most common imaging abnormality, followed by bowel ischemia (7.1%), solid organ infarction (6.7%), vessel thrombosis (6.7%), and fluid-filled colon (6.2%). Other relevant findings were dilated air-filled bowel, pancreatitis, pneumatosis/portal venous gas, bowel perforation, and appendicitis. Other than abdominal findings, COVID-19-related basal lung changes were incidentally detected in many studies. Moreover, the presence of bowel imaging findings was positively correlated with the clinical severity of COVID-19 infection. <b><i>Conclusion:</i></b> This review describes the abdominal imaging findings in COVID-19 patients. This is pertinent for the early diagnosis of COVID-19 in patients presenting solely with abdominal symptoms as well as in identifying abdominal complications in a known case of COVID-19.

Role of Multidetector Computed Tomography in Patients of Acute Mesenteric Ischaemia and its Comparison with Clinicosurgical Outcome: A Cross-sectional Study

Introduction: Acute mesenteric ischaemia is an abdominal emergency occurring in nearly 1% of patients presenting with acute abdomen. Early diagnosis is very important for the improved survival of the patient. Acute mesenteric ischaemia frequently presents with non specific features such as vomiting, loose stools and abdominal distension. The classical triad of fever, haematochezia and abdominal pain is seen in only 30% of the patients so, it is difficult to diagnose clinically. Multidetector Computed Tomography (MDCT) is gold standard and first line test to diagnose intestinal ischaemia. Aim: To assess the efficacy of MDCT in the diagnosis of acute mesenteric ischaemia and to compare its outcome with surgical and/or clinical findings. Materials and Methods: In this cross-sectional descriptive study conducted from 1st November 2018 to 31st May 2020, MDCT was performed on 40 patients (23 male; 17 female, age range: 28-93 years). Axial and reconstructed images of each patient were evaluated for evidence of bowel wall thickening, bowel wall attenuation, abnormal wall enhancement, bowel dilatation, mesenteric stranding, ascites, solid organ infarcts, pneumatosis intestinalis or portomesenteric gas, and mesenteric arterial or venous thrombosis. Multidetector CT findings were compared with the surgical findings and clinical outcome. Results were expressed in terms of frequency and percentages. Results: Out of 40 patients, most common cause of acute mesenteric ischaemia was arterial thrombosis, seen in 20 patients (50%) while 13 patients (32.5%) had portomesenteric venous thrombosis and 7 (17.5%) patients were diagnosed with non occlusive mesenteric ischaemia. CT finding of bowel wall thickening and bowel dilatation however non specific were seen in majority of patients (62.5% and 70%, respectively). Mesenteric fat stranding and ascites were seen in 95% and 77.5% cases respectively. Specific signs of acute mesenteric ischaemia includes hypoenhancing and non enhancing bowel walls seen in 27 patients (67.5%). Pneumatosis intestinalis and portomesenteric pneumatosis in 20% patients. A total of 27 patients underwent surgery and 13 patients were managed conservatively. On comparing the CT findings with intraoperative/ histopathological findings, accuracy of MDCT in the diagnosis of acute mesenteric ischaemia in this study was 96.39%. Conclusion: MDCT should be the first line imaging modality to diagnose acute mesenteric ischaemia and to exclude other causes of acute abdomen. It is an excellent and fast modality to diagnose bowel ischaemia, as it can visualise both the bowel and mesenteric changes as well as accurately depict the mesenteric vasculature.

Bowel wall thickening and hyperemia assessed by high-frequency ultrasound indicate histological inflammation in Crohn’s ileitis

Purpose We evaluated ileal bowel wall thickness and semiquantitative vascularization by ultrasound in correlation with the presence or absence of histopathological inflammation in patients with Crohn’s disease (CD). Methods We conducted a retrospective analysis of 221 ultrasound examinations of the terminal ileum or neoterminal ileum in CD patients with biopsies of the ileum during colonoscopies within 8 weeks of the ultrasound. Ultrasound data were obtained from an inflammatory bowel disease ultrasound register from 2011 to 2017. Bowel wall ultrasound was performed by a high-frequency, linear transducer (7–12 MHz). Presence of bowel wall thickening (> 3 mm), vascularization by the Limberg score, and presence of ileal histopathological inflammation were analyzed. Results In 221 bowel wall ultrasound examinations of CD patients (128 female, 93 male, mean age 37.5 years), a thickened bowel wall was found in 140 (63.3%) and hypervascularization (corresponding to a Limberg score ≥ 2) in 96 (43.4%) cases. In 187 (84.6%) cases, ileal inflammation was confirmed by histopathology and in 34 (15.4%) cases no inflammation was shown. Bowel wall thickening showed a sensitivity of 70.1%, a negative predictive value (NPV) of 30.9%, a specificity of 73.5% and a positive predictive value (PPV) of 93.6% for the detection of histopathological ileal inflammation. Hypervasularization had a low sensitivity (49.7%) and NPV (24.8%), but high specificity (91.2%) and PPV (96.9%). Conclusion In this CD subcohort of an ultrasound register, pathologic ultrasound findings were quite common. Bowel wall thickening (> 3 mm) and hypervascularization are good predictors of histopathological inflammation within the terminal ileum or neoterminal ileum. Normal ultrasound findings without bowel wall thickening and without hypervascularization do not rule out histopathological inflammation.

Giant villous adenoma of the sigmoid colon: an unusual cause of homogeneous, segmental bowel wall thickening

Colonic adenomas are commonly encountered lesions that are a precursor of colorectal cancer. Of these, villous adenomas are a rarer, more advanced subtype that are larger in size than tubular adenomas and have a higher risk of malignant transformation. We present a patient with a giant villous adenoma of the sigmoid colon identified on CT as homogeneous segmental bowel wall thickening.

Colon metastases as first clinical manifestation of lobular breast carcinoma with no subsequent evidence of breast disease

A 73-year-old woman was brought to the oestrogen receptor for altered mental status. She was found to be hypotensive and hypoglycaemic and admitted to the intensive care unit. She had a history of chronic watery diarrhoea which had recently increased over the last 2 weeks and was associated with vague abdominal pain. A CT showed bowel wall thickening concerning for colitis. Due to the increasing diarrhoea, a colonoscopy was done after all stool studies came back negative. Polyps in the ascending, transverse and sigmoid colon were found to be tubular adenomas but random colonic mucosa biopsies were revealed to be histologically consistent with metastatic lobular breast carcinoma. Further workup revealed no primary breast disease.