A MODIFIED CT SEVERITY INDEX FOR EVALUATING ACUTE PANCREATITIS: IMPROVED CORRELATION WITH PATIENT OUTCOME.

Abstract

Objective: This study was conducted to assess the correlation with patient outcome and interobserver variability of a modified CT severity index (M-CTSI) in the evaluation of patients with acute pancreatitis, compared with the currently accepted CT severity index (CTSI). Materials and Methods: Of 266 consecutive patients diagnosed with acute pancreatitis during a one year period, 66 underwent contrast-enhanced multidetector-row CT scan within one week of onset of symptoms. Three radiologists, blinded to patient outcome, independently scored the severity of the pancreatitis using both the CTSI and M-CTSI. The M-CTSI includes a simplified assessment of pancreatic inflammation and necrosis and also evaluates the presence of extrapancreatic complications. Outcome parameters included: length of hospital stay; need for surgery or percutaneous intervention; infection; organ failure; and death. For both the CTSI and M-CTSI, correlation between the severity of the pancreatitis and patient outcome was estimated using the Wilcoxon rank-sum test and Fisher’s exact test. Interobserver agreement for both the CTSI and M-CTSI was calculated. Results: Using the M-CTSI versus the CTSI, correlation between the severity of pancreatitis and the following parameters improved: length of hospital stay (0–34 days) [M-CTSI (p =0.0054–0.0714) versus CTSI (p =0.0052–0.3008)]; need for surgical or percutaneous procedures (10/66 patients) [M-CTSI (p =0.0112) versus CTSI (p =0.0324)]; infection (21/66 patients) [M-CTSI (p <1e-10) versus CTSI (p <1e-04). Significant correlation between the severity of pancreatitis and organ failure (9/66 patients) was only seen with the M-CTSI (p =0.0024) and not with the CTSI (p =0.0513). The interobserver agreement was similar using the M-CTSI (K: range: 0.71–0.85) compared with the CTSI (K: range: 0.63–0.86). Conclusions: The modified CT severity index correlates better with patient outcome measures than the current index with similar interobserver variability.