Diffusion‐Based Virtual MR Elastography: Association With Pancreatic Fibrosis and Identification of Postoperative Pancreatic Fistula After Pancreaticoduodenectomy

ABSTRACT Background Preoperative identification of clinically relevant postoperative pancreatic fistula (CR‐POPF) after pancreaticoduodenectomy holds substantial clinical importance. The significance of virtual MR elastography (vMRE) in identifying CR‐POPF risk remains unclear. Purpose To explore the application of vMRE in assessing pancreatic fibrosis and preoperatively identifying CR‐POPF with inter‐device validation. Study Type Retrospective. Population Three hundred twenty patients (212 male; mean age = 56.93 ± 9.34 years) receiving pancreatoduodenectomy were assessed and divided into two cohorts (cohort 1: 228; cohort 2: 92) based on two MRI scanners. Field Strength/Sequence 3 T, diffusion‐weighted spin echo planar imaging and MRE using spin‐echo echo planar imaging sequence. Assessment Optimal combination of b values was identified for calculating shifted apparent diffusion coefficient (sADC). The diffusion‐based tissue shear modulus ( μ diff ) was constructed using optimal sADC. Association between μ diff and pancreatic fibrosis grades was evaluated. CR‐POPF was diagnosed postoperatively. Statistical Tests Spearman correlation analysis, linear regression analysis, univariate and multivariate logistic regression analysis, and receiver operating characteristic (ROC) analysis were used. Significance was set at p < 0.05. Results Seventy‐six patients developed (23.75%) CR‐POPF. sADC generated from b values of 400 and 1500 s/mm 2 was identified for fitting μ diff . μ diff was significantly associated with histopathologic fibrosis grade (Spearman ρ = 0.763) and achieved performance for identifying CR‐POPF with area under the curve (AUC) of 0.765. μ diff , body mass index (BMI), and main pancreatic duct (MPD) were revealed as independent risk factors of CR‐POPF. Their combination significantly improved the performance to AUC of 0.923 (AUC of μ diff = 0.769; AUC of BMI = 0.673; AUC of MPD = 0.666). Results were confirmed in cohort 2. Data Conclusion Diffusion‐based vMRE could effectively assess pancreatic fibrosis grade and provide a noninvasive biomarker for identifying CR‐POPF preoperatively. The combination of μ diff , BMI, and MPD demonstrated superior discriminative performance. Evidence Level 3. Technical Efficacy Stage 2.