Bowel Imaging Reveals More Information on COVID-19

Bowel abnormalities like ischemia and cholestasis could be commonly found in abdominal imaging of patients with the coronavirus disease 2019 (COVID-19).

A team, led by Rajesh Bhayana, MD, Division of Abdominal Imaging, Department of Radiology, Massachusetts General Hospital, reported new abdominal imaging findings from patients with COVID-19.

In the retrospective cross-sectional study, the investigators included 412 patients who consecutively admitted to a single quaternary care center who tested positive for the SARS-COV-2 virus.

The investigators performed abdominal imaging studies in each patient, with salient findings recorded. They also reviewed medical records for clinical data and performed univariable analysis and logistic regression.

The average of the patient population was 57 years old, with 241 men and 171 women included in the study.

Overall, 224 abdominal imaging studies were performed—137 radiographs, 44 ultrasounds, 42 CT scans, and 1 MRI—in 134 patients (33%).

Abdominal imaging was linked to age (OR, 1.03 per year increase; P = 0.001), as well as ICU admissions (OR, 17.3; P <0.001). The investigators also found bowel wall abnormalities in 31% of CT scans (13 of 42), which were associated with ICU admission (OR, 15.5; P = 0.01).

The bowel findings included pneumatosis or portal venous gas, which was found in 20% of CT scans of ICU patients (4 of 20), while surgical correlation (n = 4) revealed unusual yellow discoloration of bowel (n = 3) and bowel infarction (n = 2).

The team also found pathology identified ischemic enteritis with patchy necrosis and fibrin thrombi in arterioles (n = 2). Of right upper quadrant ultrasounds, 32 (87%) were performed for liver laboratory findings and 20 (54%) demonstrated a dilated sludge-filled gallbladder suggestive of cholestasis.

Patients with a cholecystostomy tube placed (n = 4) had negative bacterial cultures.

“Bowel abnormalities and cholestasis were common findings on abdominal imaging of inpatients with COVID-19,” the author wrote. “Patients who went to laparotomy often had ischemia, possibly due to small vessel thrombosis.”

As testing capacity and case numbers continue to increase worldwide, some gastrointestinal symptoms including diarrhea, nausea/vomiting, abdominal pain, and loss of appetite have been increasingly recognized.

While lung injuries are the most common, liver injuries of uncertain etiology have been observed in patients, with increased frequency in severe cases.

The SARS-CoV-2 virus is believed to gain access to cells through surface expression of angiotensin converting enzyme 2 (ACE2). Tissues with high levels of ACE2 expression are assumed to be susceptible to direct infection.

ACE2 surface expression is most abundant in lung alveolar epithelial cells, enterocytes of the small intestine, and vascular endothelium. The large amount of ACE2 surface expression in the gastrointestinal tract and, less so, biliary epithelium could explain the GI symptoms and liver injuries found in patients.

The virus has also been identified in stool samples of a significant portion of infected patients.

The study, “Abdominal Imaging Findings in COVID-19: Preliminary Observations,” was published online in Radiology.