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

Abstract

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.