Fatty Liver in Acute Pancreatitis: Characteristics in Magnetic Resonance Imaging

Objective: The objective of this research was to study the characteristics of fatty liver (FL) in acute pancreatitis (AP) in 2-dimensional in-phase (IP)/out-of-phase (OP) magnetic resonance imaging (MRI). Methods: Fifty patients with AP (23 men, 27 women; mean age, 44 [SD, 12] years [range, 16-73 years]) were included in this retrospective study. Patients' informed consent was waived. All of them performed abdominal MRI within 72 hours of symptom onset and MRI follow-up. The severity of the AP was graded according to the magnetic resonance severity index (MRSI). The MRSI cutoff was 7.0 points between the mild and the severe AP. Fatty liver in MRI was determined by the hepatic signal intensity difference between OP and IP images. Correlations between the severity of FL and MRSI or serum triglyceride levels were analyzed. Results: Of the 50 patients with AP, FL was found in 66% of patients' MRIs. A close correlation can be seen between the difference of liver signal intensities on IP/OP images and the MRSI (r = 0.83, P < 0.001). Close correlations were found between FL appearance on MRI and serum triglyceride levels in both mild (r = 0.93, P < 0.001) and severe AP (r = 0.95, P < 0.001). During follow-up MRI, the appearance of FL decreased following the decrease in MRSI scores and serum triglyceride levels in both mild and severe AP. Conclusions: Fatty liver in AP is frequently observed in MRI. The appearance of FL in MRI may decrease after subsidence of AP.