- This study correlated abdominal imaging findings with abdominal signs and symptoms in 412 adult inpatients with COVID-19, of whom 136 were admitted to the ICU
- 33% of the patients had abdominal imaging and 17% had cross-sectional imaging
- 31% of 42 CT scans showed bowel wall abnormalities
- CT signs of late ischemia were present in four ICU patients (3% of all ICU patients); pathologic examination suggested small vessel thrombosis
- Findings of bile stasis were seen on 54% of the 37 right upper quadrant ultrasound studies and evidence of fatty liver was noted in 27%
SARS-CoV-2, the virus that causes COVID-19, is thought to enter cells via receptors for angiotensin-converting enzyme 2. These are abundant not just in the lung but also in the gastrointestinal tract, biliary epithelium and vascular endothelium.
In Radiology, Rajesh Bhayana, MD, diagnostic radiologist, and Avinash Kambadakone, MBBS, MD, chief of the Division of Abdominal Imaging at Massachusetts General Hospital, and colleagues have published the first abdominal imaging findings corresponding to abdominal signs and symptoms in patients with COVID-19.
The researchers studied all 412 adults admitted to Mass General between March 27 and April 10, 2020, who tested positive for SARS-CoV-2. This included 136 who were admitted to the ICU. 34% of patients reported at least one gastrointestinal symptom at presentation.
By querying an electronic database, the researchers identified all abdominal imaging examinations performed in these patients between seven days prior to admission and April 21, 2020.
Imaging Utilization and Indications
134 patients (33%) had a total of 224 abdominal imaging studies:
- Radiography (n=137)
- Ultrasound (n=44 overall; 37 right upper quadrant (RUQ) studies [32 in ICU patients and five in non-ICU patients])
- CT (n=42 overall; 20 in ICU patients and 22 in non-ICU patients)
- MRI (n=1)
72 patients (17%) had at least one cross-sectional study.
The most common indication for RUQ ultrasound was abnormal liver laboratory findings (86%). CT was most commonly performed for abdominal pain (33%) or sepsis (29%).
- Abnormal bowel wall—13 studies (31% overall; 10 for ICU patients vs. 3 for non-ICU patients, P = .02)
- Colonic or rectal thickening—Seven studies
- Small bowel thickening—Five studies
- Pneumatosis or portal venous gas—Four studies (all in ICU patients)
- Perforation—One study
- Fluid-filled colon suggestive of diarrhea—18 studies (43% overall; 13 studies for ICU patients vs. five for non-ICU patients, P = .01)
- Solid organ infarct—Two studies
- Pancreatitis—One study
- Findings suggestive of hepatitis—One study
The four patients with pneumatosis or portal venous gas, suggestive of ischemia, underwent exploratory laparotomy. Two had frankly necrotic bowel, and one of them underwent bowel resection. Pathologic examination detected ischemic enteritis with patchy necrosis and small vessel thrombosis.
In the third patient who had ileal pneumatosis cystoides intestinalis at CT, laparotomy revealed fibrotic ileum with pneumatosis but no obvious infarction. Diffuse ischemic injury with multifocal necrosis and small vessel thrombosis was observed on pathologic examination.
The fourth patient, who had gas in the transverse mesocolon, was found to have patchy yellow discoloration of the antimesenteric transverse colon. The etiology was unknown.
RUQ Ultrasound Findings
- Findings suggestive of bile stasis (gallbladder sludge and distension)—20 studies (54%)
- Fatty liver—10 studies (27%)
- Gallbladder sludge, nondistended—Two studies
- Gallbladder wall thickening—One study
- Pericholecystic fluid—One study
- Portal venous gas—One study
Four ICU patients who had findings of cholestasis had cholecystostomy tubes placed that revealed no bacterial culture.
In three of the four patients with pneumatosis or portal venous gas, the finding was initially identified on radiograph or ultrasound, so radiologists should be alert to these manifestations on all imaging modalities. They may be present more frequently than previously recognized.
Diarrhea is common at presentation of COVID-19 yet can be overlooked. Liquid stool often escapes comment on CT, but radiologists who identify it might provide the first indication of gastrointestinal involvement in patients with COVID-19.
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