Multiphasic CT is the gold standard for the identification of a SRH. Recognition of CT signs of active bleeding is the crucial feature influencing the timing of therapeutic treatment. Urgent embolization should be performed in cases of arterial bleeding or contained vascular injuries supplying the retroperitoneal hematoma. Surgery is to be addressed in cases of actively bleeding hematomas associated with complication. Finally, an initial more conservative approach can be adopted in patients without signs of contrast extravasation or low-flow active bleeding. Technical skill, expertise, and recognition of CT signs of arterial active bleeding are critical features influencing patients management.

Lemmel syndrome is a rare and misdiagnosed cause of acute abdominal pain due to a juxtapapillary duodenal diverticulum causing mechanical obstruction of the common bile duct. Frequently, patients suffering from Lemmel syndrome have a history of recurrent access to the emergency room for acute abdominal pain referable to a biliopancreatic obstruction, in the absence of lithiasis nuclei or solid lesions at radiological examinations. Ultrasonography (US) may be helpful in evaluation of upstream dilatation of extra-/intra-hepatic biliary duct, but computed tomography (CT) is the reference imaging modality for the diagnosis of periampullary duodenal diverticula compressing the intrapancreatic portion of the common bile duct. Recognition of this entity is crucial for targeted, timely therapy avoiding mismanagement and therapeutic delay. The aim of this paper is to report CT imaging findings and our experience in two patients affected by Lemmel syndrome.

The results of our study confirm the diagnostic potential of MRCP in the study of the pancreaticobiliary duct system. In particular, the comparison between MRCP and US and MSCT indicates the superiority of MRCP in evaluating bile ducts and detecting stones in the common bile duct.