Role of fat-suppressed T1-weighted magnetic resonance imaging in predicting severity and prognosis of acute pancreatitis: An intraindividual comparison with multidetector computed tomography

OBJECTIVE: To determine the diagnostic value of magnetic resonance (MR) grading focusing on elevated signal on T1-weighted images in the prediction of severity and prognosis of acute pancreatitis as compared with the Balthazar computed tomography (CT) grading. MATERIALS: Thirty-one patients with acute pancreatitis who underwent CT and MR imaging including fat-suppressed T1-weighted images within a 48-hour interval were included in this study. The severity of pancreatitis was evaluated by 2 observers using the Balthazar CT grading system and an MR grading system that is focused on an elevated signal on T1-weighted images. The MR grading was correlated with the CT grading, and each MR or CT grade was compared with patient outcome parameters, including the duration of hospitalization, local and systemic complications, and clinical outcome grading. RESULTS: There was a significant correlation between CT and MR gradings for pancreatic or peripancreatic inflammation (r = 0.688, P < 0.01). However, for all of the outcome parameters and outcome grading, a stronger correlation was seen with the MR grading than with the CT grading. No significant correlation was found between CT grading and infected necrosis (r = 0.316, P = 0.083). CONCLUSIONS: Magnetic resonance imaging including fat-suppressed T1-weighted images is more accurate to predict the severity and prognosis of acute pancreatitis in comparison with CT.