Significance of Renal Rim Grade on Computed Tomography in Severity Evaluation of Acute Pancreatitis

Objectives: Multifactor scoring systems, such as the Acute Physiology and Chronic Health Evaluation (APACHE) II, are useful for predicting the severity of acute pancreatitis (AP); however, they are rather complicated. The aim of this study was to introduce renal rim grade (RRG) as a severity assessment measure for AP. Methods: One hundred twenty-two eligible AP patients who underwent abdominal computed tomography (CT) on admission were evaluated for RRG (grades 1-3). The end points were the severity of illness and hospital mortality. Furthermore, RRG was compared with the Balthazar score, the CT severity index, the Ranson score, and the Acute Physiology and Chronic Health Evaluation (APACHE) II score, using a receiver operating characteristic analysis. Results: The exacerbation rates into severe disease were 3% (grade 1), 48% (grade 2), and 89% (grade 3). The mortality rates were 3% (grade 1), 8% (grade 2), and 31% (grade 3). The area under the receiver operating characteristic curves to predict the severe disease and mortality using the RRG system were comparable with other scoring systems. Conclusions: Renal rim grade is useful for the evaluation of the severity of AP.