title: Omental infarct: CT imaging features.
abstract: BACKGROUND
  The aim of this study is to describe contrast-enhanced computed tomographic (CT) features of acute omental infarction and to study the evolutionary changes on follow-up CT imaging.
  
  
  METHODS
  Fifteen cases of omental infarction were evaluated for their initial CT imaging features. The imaging features evaluated included size of the fatty lesion, location, peripheral rim, and relation to colon. CT findings were correlated with etiology, clinical presentation, and leukocytosis. Follow-up CT images were available in eight patients and the imaging features were studied.
  
  
  RESULTS
  Eight omental infarcts were of unknown etiology and seven were secondary to abdominal surgery. In 53% of patients (eight of 15), the location of the omental infarct was in the right lower, mid, or upper quadrants. These eight right-side infarcts occurred in six patients with primary omental infarcts. In 13 of 14 patients who underwent CT within 15 days of onset of omental infarct, the margin of the lesion was ill defined. Primary omental (n = 8) infarcts were seen in younger patients (p = 0.02) and were larger on CT (p = 0.02) compared with secondary omental infarcts. CT findings evolved from an ill-defined, heterogeneous fat-density lesion to a well-defined, heterogeneous fat-density lesion with a peripheral hyperdense rim in all six secondary omental infarctions for which acute stage and follow-up CT images were available for interpretation.
  
  
  CONCLUSIONS
  There is a significant difference in the age distribution and CT findings in terms of size of the omental infarction between primary and secondary etiologies. On follow-up CT, secondary omental infarcts progressively shrank and developed a well-defined, hyperdense rim around a fatty core.
authors.affiliation: Division of Abdominal Imaging and Interventional Emergency Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA. pallaviajay@hotmail.com
authors.forename: A K
authors.initials: AK
authors.lastname: Singh
authors.forename: D A
authors.initials: DA
authors.lastname: Gervais
authors.forename: P
authors.initials: P
authors.lastname: Lee
authors.forename: S
authors.initials: S
authors.lastname: Westra
authors.forename: P F
authors.initials: PF
authors.lastname: Hahn
authors.forename: R A
authors.initials: RA
authors.lastname: Novelline
authors.forename: P R
authors.initials: PR
authors.lastname: Mueller
mesh_terms: D000006:Abdomen, Acute / Q000000981:diagnostic imaging / Q000209:etiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003287:Contrast Media; D005260:Female; D006801:Humans; D007238:Infarction / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009852:Omentum / Q000098:blood supply*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media