The Signal Intensity Ratio of Pancreas to Spleen in Magnetic Resonance Imaging Can Predict Nonalcoholic Fatty Liver Disease after Pancreaticoduodenectomy

Objectives Signal intensity ratio of pancreas to spleen (SI ratiop/s) on fat-suppressed T1-weighted images of magnetic resonance imaging has been associated with pancreatic exocrine function. We here investigated the predictive value of the SI ratiop/s for the development of nonalcoholic fatty liver disease (NAFLD) after pancreaticoduodenectomy (PD). Materials and Methods This study comprised 208 patients who underwent PD. NAFLD was defined as a liver-to-spleen attenuation ratio of <0.9 calculated by a computed tomography 1 year after surgery. SI ratiop/s was calculated by dividing the average pancreas SI by the spleen SI. We retrospectively investigated the association of clinical variables including the SI ratiop/s and NAFLD by univariate and multivariate analyses. Results NAFLD after 1 year was developed in 27 patients (13%). In multivariate analysis, the SI ratiop/s < 1 (P < 0.001) was an independent predictor of incidence of NAFLD. The SI ratiop/s < 1 was associated with low amylase level of the pancreatic juice (P < 0.001) and progressed pancreatic fibrosis (P = 0.017). According to the receiver operating characteristics curve, the SI ratiop/s had better prognostic ability of NAFLD than the remnant pancreas volume. Conclusions The SI ratiop/s is useful to predict NAFLD development after PD. Moreover, the SI ratiop/s can be a surrogate marker, which represents exocrine function of the pancreas.