Role of multislice computed tomography in the diagnosis ofgene-mutation-associated pancreatitis (GMAP)

PURPOSE: The aim of this study was to review the computed tomography (CT) features of the pancreatic parenchyma and ducts in patients with gene-mutation-associated pancreatitis (GMAP). MATERIALS AND METHODS: Twenty-five patients with GMAP were included in this retrospective study. Patients were divided into two groups according to the time interval between the onset of symptoms and the first CT examination (group A </=24 months and group B >25 months). RESULTS: On qualitative image assessment, in group A patients, pancreatic duct stones were detected in 2/13 with GMAP. All stones were calcified and homogenous. Enhancement of the pancreatic parenchyma was hypovascular in 7/13 patients. In group B patients, pancreatic duct stones were detected in 12/12 with GMAP. Stones were calcified in 10/12 cases and noncalcified (protein plugs) in 2/12; in 5/10 cases, the calcified stones were heterogeneous with noncalcified central core (bull's-eye appearance). Enhancement of the pancreatic parenchyma was hypovascular in 12/12 patients. On quantitative image assessment, in group A patients, the mean diameter of duct stones was 0.6 mm (range 0-5 mm). Mean diameter of the main duct in the pancreatic head and body/tail was 4.8 mm and 4.9 mm, respectively. In group B patients, the mean diameter of duct stones was 21.9 mm (range 2-50 mm). Mean diameter of the main duct in the pancreatic head and body/tail was 18.8 mm and 13.9 mm, respectively. CONCLUSIONS|: In patients with GMAP and time interval between symptom onset and first CT scan </=24 months (group A), CT identified normal or slightly increased parenchymal thickness and a main pancreatic duct of normal calibre and without duct stones. In contrast, in patients with GMAP and time interval between symptom onset and first CT scan >25 months (group B), it identified large-calibre duct stones with bull's-eye appearance.