CASE 1507 Published on 18.03.2002

Omental infarction: sonographic and CT findings

Section

Abdominal imaging

Case Type

Clinical Cases

Authors

A. Hollerweger, P. Macheiner

Patient

35 years, male

Categories
No Area of Interest ; Imaging Technique Ultrasound, Ultrasound-Power Doppler, CT
Clinical History
A patient with acute right lower quadrant abdominal pain.
Imaging Findings
The patient presented with an 18-hour history of local tenderness in the right lower abdomen. No vomiting, nausea, or fever was present. He was admitted with suspected acute appendicitis and abdominal sonography and CT examinations were performed.
Discussion
Omental infarction is an acute abdominal condition, which is often clinically misdiagnosed as acute appendicitis (1,2). Its most common localisation, in the right mid or lower abdomen, has been explained as a congenital vascular anomaly, but segmental infarction can be localised anywhere in the omentum. Omental infarction is a relatively rare condition and may occur at any age. Approximately 15% of patients are children (3).

Patients usually present with acute or subacute abdominal pain and localised tenderness; laboratory parameters are within the normal range or show slight elevation of white blood cell count or sedimentation rate. Vomiting and nausea are rare (1,2).

Sonography typically shows an ovoid, non-compressible, moderately hyperechoic mass at the point of maximum tenderness (1,2,4,5). The mass may be surrounded by a hypoechoic rim and is frequently adherent to the parietal peritoneum of the abdominal wall. On colour Doppler sonography vascularisation is not visible in the infarcted omentum, but adjacent tissue shows moderately increased colour flow due to the inflammatory reaction.

CT scans show a corresponding fatty lesion with hyperattenuating streaks (1,2,5). The parietal peritoneum is often thickened, whereas the bowel wall appears normal.

Follow-up examinations show a slow decrease in lesion size and disappearance of the lesion over a period of 1–2 months.

In cases of segmental omentum infarction, both sonography and CT show characteristic features that enable the correct diagnosis. Clinical symptoms gradually disappear when treated with analgesics and, with appropriate diagnosis, unnecessary surgery can be avoided.

Differential Diagnosis List
Segmental omentum infarction
Final Diagnosis
Segmental omentum infarction
Case information
URL: https://eurorad.org/case/1507
DOI: 10.1594/EURORAD/CASE.1507
ISSN: 1563-4086