Juxtapapillary duodenal diverticula: MDCT findings in 1010 patients and proposal for a new classification.

The aim of this study is to analyze the MDCT findings of juxtapapillary duodenal diverticula (JPDD) and to propose a new radiological classification. CT-examinations of 1010 consecutive patients, all examined by 16-row MDCT of the abdomen over a time period of 20 months were retrospectively analyzed. All study patients were examined by triple phase CT (native, arterial and portal venous CT scan) of the abdomen and all recieved positive oral contrast prior to the examination. Thirty-three patients showed a juxtapapillary duodenal diverticulum, which could be seen on all CT scans, but jusually was depicted most clearly on the thin collimated arterial phase CT images. Size of diverticula range from 4 mm to 4.5 cm (mean 1.7 cm). In 17 cases the diverticulum was located ventrally to the vaterian sphincter complex, extending less or more into the pancreas at the site where the dorsal and the ventral anlage of the pancreas have fused (type I). 12 diverticula were located dorsally to the sphincter complex (type II). Three patients presented with a bilobated juxtapapillary diverticulum extending to both sides, ventrally and dorsally (type III) and one patient showed a little diverticulum ventrally to the minor papilla (type IV).Three patients presented with food impaction in the diverticulum but only one of these patients with a large IPDD showed a Lemmel-syndrome, whereas the other three patients with non-calculous extrahepatic cholostasis showed larger diverticula without food impaction. MDCT allows to identify four different types of juxtapapillary duodenal diverticula and using the proposed classification may be helpful for a more exact, anatomy based radiological description of this CT finding.