MR imaging of hemorrhage associated with acute pancreatitis

Abstract

Purpose: To study MRI findings of hemorrhage in acute pancreatitis (AP) and correlate the presence and extent of hemorrhage with the MR severity index (MRSI), Acute Physiology And Chronic Health Evaluation (APACHE) II scores, and clinical outcome.

Materials and methods: This retrospective study included 539 patients with AP. Hemorrhage was defined as areas of hyperintensity in or outside the pancreas on liver imaging with volume acceleration flexible (LAVA-Flex). The presence of hemorrhage was classified into three areas: within the pancreatic parenchyma, retroperitoneal space, and sub-or intraperitoneal space. Involvement of each area was awarded 1 point resulting in the hemorrhage severity index (HSI) score. The predicted severity of AP was graded by MRSI and APACHE II score. The association between HSI, MRSI, and APACHE II scores was analyzed. The length of hospital stay and organ dysfunction was used as clinical outcome parameters.

Results: Among 539 AP patients, 62 (11.5%) had hemorrhage. The prevalence of hemorrhage was 1.1% (2/186), 13.9% (43/310), and 39.5% (17/43) in predicted mild, moderate, and severe AP, respectively, based on MRSI (χ² = 55.3, p = 0.00); and 7.7% (21/273) and 19.2% (18/94) in predicted mild and severe AP, respectively, based on APACHE II (χ² = 21.2, p = 0.00). HSI score significantly correlated with MRSI (r = 0.36, p < 0.001) and APACHE II scores (r = 0.21, p = 0.00). The prevalence of organ dysfunction was higher and length of hospital stay was longer in patients with hemorrhage than in those without hemorrhage (p < 0.01).

Conclusions: Hemorrhage in AP is common. The presence of hemorrhage, rather than its extent, correlates with poor clinical outcome.

Keywords: Acute pancreatitis; Hemorrhage; MRI; Severity.