Contribution of US and CT for diagnosis of intraperitoneal focal fat infarction (IFFI): a pictorial review.

The term IFFI--for intraperitoneal focal fat infarction--includes various acute abdominal clinical conditions in which focal fatty tissue necrosis represents the common pathologic denominator. Only differing by their various anatomical locations and dimensions, all cases nevertheless present rather similar clinical signs, aetiology, radiological features and prognosis. In clinical practise, most cases of IFFI concern torsion and/or infarction of the greater omentum or epiploic appendages. Rarer types of torsion and/or infarction of lipomatous appendages of the hepatic falciform ligament and of the lesser omentum have also been reported. Cases are finally described in the paediatric population. US and merely CT have been shown having a high sensitivity and specificity for the diagnosis of IFFI and in most cases the clinical evolution is spontaneously favourable. For these two reasons, the option of conservative treatment after specific imaging diagnosis now represents the other common denominator of IFFI. Such a safe and unambiguous imaging diagnosis of IFFI represents thus an important challenge for each abdominal radiologist with the intention of persuading the referent clinician to avoid unnecessary surgery for their patients. The aim of this pictorial review is to extensively explore not only the classical imaging findings of various types of IFFI but also to review the normal US and MDCT anatomy of the fatty abdominal structures being usually implicated in IFFI. More rare or atypical presentations are also illustrated as well as subacute findings and sequels. All reported patients were collected in our department during a 7-year-period and most were successfully treated conservatively.