CT of the superior mesenteric artery root in pancreatitis and pancreatic carcinoma

Previous reports suggested that pancreatitis does not produce CT changes in the region of the root of the superior mesenteric artery (SMA) while pancreatic carcinoma does. The authors have reviewed 103 CT studies from patients with proved pancreatitis (n = 61) or pancreatic carcinoma (n = 42). Masked CT studies (obscuring all regions except the root of the SMA) were evaluated for infiltration of the fat around the SMA, adjacent lymph nodes, focal mass abutting the SMA, and mass circumferentially encasing the SMA. Streaky infiltration around the SMA was seen in patient with pancreatitis (58%) and pancreatic carcinoma (52%). Lymph nodes were seen in both pancreatitis (28%) and carcinoma (17%). Focal mass abutting the SMA was seen in pancreatitis (7%) and carcinoma (26%). Encasement of the SMA was seen only in carcinoma (17%). Both pancreatitis and pancreatic carcinoma can produce CT findings in the region of the root of the SMA. Encasement of the SMA was the only finding specific to patients with pancreatic carcinoma