Perfusion computed tomography findings of autoimmune pancreatitisa

Objective: The aim of this study was to clarify the pancreatic blood perfusion in patients with autoimmune pancreatitis (AIP) and the changes after steroid treatment. Methods: Perfusion computed tomography was performed in 11 patients with AIP and 12 control subjects. Pancreatic volumetric blood flow (F _V), volume of distribution (V _D), and blood transit time τ were determined from a single-compartment kinetic model. Nine patients with AIP were reexamined by perfusion computed tomography after corticosteroid administration. Results: The pancreatic FV values of the 11 patients with AIP (82.7/min) were significantly lower than those of control subjects (163.5/min, P = 0.0006). On the other hand, the pancreatic V _D and τ values were not significantly different between AIP and normal. After steroid treatment, the FV values of 9 reexamined patients with AIP (76.2/min) were significantly elevated (109.8/min, P = 0.0391). However, the changes of the values after the treatment differed in degree among individuals. The values of 4 patients were dramatically elevated to greater than 100/min, whereas those of 4 other patients did not improve well. The value of the remaining patient whose initial F _V value was normal (168.09/min) did not change after the treatment. Conclusions: Pancreatic volumetric perfusion was attenuated in AIP patients. The perfusion was improved after the steroid treatment.