Tomoelastography and Pancreatic Extracellular Volume Fraction Derived From MRI for Predicting Clinically Relevant Postoperative Pancreatic Fistula

Abstract

BackgroundPancreatic stiffness and extracellular volume fraction (ECV) are potential imaging biomarkers for pancreatic fibrosis. Clinically relevant postoperative fistula (CR‐POPF) is one of the most severe complications after pancreaticoduodenectomy. Which imaging biomarker performs better for predicting the risk of CR‐POPF remains unknown.PurposeTo evaluate the diagnostic performance of ECV and tomoelastography‐derived pancreatic stiffness for predicting the risk of CR‐POPF in patients undergoing pancreaticoduodenectomy.Study typeProspective.PopulationEighty patients who underwent multiparametric pancreatic MRI before pancreaticoduodenectomy, among whom 16 developed CR‐POPF and 64 did not.Field Strength/Sequence3 T/tomoelastography and precontrast and postcontrast T1 mapping of the pancreas.AssessmentPancreatic stiffness was measured on the tomographic c‐map, and pancreatic ECV was calculated from precontrast and postcontrast T1 maps. Pancreatic stiffness and ECV were compared with histological fibrosis grading (F0‐F3). The optimal cutoff values for predicting CR‐POPF were determined, and the correlation between CR‐POPF and imaging parameters was evaluated.Statistical testsThe Spearman's rank correlation and multivariate linear regression analysis was conducted. The receiver operating characteristic curve analysis and logistic regression analysis was performed. A double‐sided P < 0.05 indicated a statistically significant difference.ResultsPancreatic stiffness and ECV both showed a significantly positive correlation with histological pancreatic fibrosis (r = 0.73 and 0.56, respectively). Patients with advanced pancreatic fibrosis had significantly higher pancreatic stiffness and ECV compared to those with no/mild fibrosis. Pancreatic stiffness and ECV were also correlated with each other (r = 0.58). Lower pancreatic stiffness (<1.38 m/sec), lower ECV (<0.28), nondilated main pancreatic duct (<3 mm) and pathological diagnosis other than pancreatic ductal adenocarcinoma were associated with higher risk of CR‐POPF at univariate analysis, and pancreatic stiffness was independently associated with CR‐POPF at multivariate analysis (odds ratio: 18.59, 95% confidence interval: 4.45, 77.69).Data ConclusionPancreatic stiffness and ECV were associated with histological fibrosis grading, and pancreatic stiffness was an independent predictor for CR‐POPF.Level of Evidence1Technical Efficacy Stage5