Omental infarction

Right Segmentary Omental Infarction Including Omental Torsion and Epiploic Appendagitis 63 Peritonitis 66... 

Epiploic appendagitis and omental infarction are benign self-limiting conditions that are more frequent than generally assumed. Both disorders fre-... 

Epiploic appendices are pedunculated adipose structures protruding from the serosal surface of the colon. An epiploic appendix might incidentally undergo infarction because of torsion or spontaneous venous thrombosis. The condition has been called epiploic appendagitis (van Breda Vriesman and Puylaert 2002). It is considered, as with omental infarction, a self-limited process, and the appropriate management is conservative. The inflamed mass is often delineated hy a hypoechoic ring on US. 

Fig. I.76a-c. Omental infarction, a Hyperechoic mass just behind the abdominal wall (arrows), b Axial CT image shows an area of fat stranding indicating inflamed mesenteric fat (arrows), c Another patient. Longitudinal US at the sub-hepatic region shows a hyperechoic mass just underneath the anterior abdominal wall that progressively attenuates the sound suggesting a fat origin (arrows). fi,dilated bowel loops L, liver...

Inflammation of the peritoneum caused by Myco-bacterium tuberculosis can be produced by direct spread from gastrointestinal tuberculosis or after hematogenous dissemination from a pulmonary focus. Involvement of the omentum in peritoneal tuberculosis is diffuse and different to the focal involvement of the omentum in appendicitis or in omental infarction on US or CT. The correct diagnosis is suggested by additional findings such as lymphadenopathy, involvement of the mesentery, bowel wall thickening, or loculated ascites (van Breda Vriesman and Puylaert 2002). 

Baldisserotto M, Maffazzoni DR, Dora MD (2005) Omental infarction in children color Doppler sonography correlated with surgery and pathology findings. AJR Am J Roentgenol 184 156-162... 

Fig. 17.18. Appendagitis epiploica. In a 29-year-old patient with acute pain, a tender 2.5-cm soft-tissue infiltration (arrow) with adjacent reticular fatty infiltration at the umbilical level is demonstrated. Because of its well-circumscribed hyperattenuating rim, it presents more likely appendagitis epiploica than omental infarction. The lesion vanished within a few days of conservative therapy...

Epiploic appendagitis and omental infarction are causes of acute pelvic pain that are often misdiagnosed clinically as acute appendicitis or diverticulitis. Based on the imaging findings, especially CT allows a definite diagnosis in most cases and patients can be managed conservatively. 

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