Usefulness of MRI T1 Mapping in Predicting Postoperative Pancreatic Fistula After Distal Pancreatectomy.

Objectives: Postoperative pancreatic fistula (POPF) is the most significant and potentially lethal complication of pancreatectomy. This study evaluated the association between MRI pancreatic T1 mapping and POPF and developed a new, useful, and noninvasive predictor of distal pancreatectomy (DP).

Methods: The study included 39 patients who underwent preoperative MRI T1 mapping using the Modified Look-Locker Inversion Recovery Sequence (MOLLI) followed by DP between January 2018 and July 2024. Patients with (POPF (+), n=15) and those without POPF (POPF (-), n=24) were compared for their characteristics, perioperative outcomes, and parameters derived from MRI. The circular region of interest was positioned on the pancreatic head, ventral side of the portal vein, and transection site to measure the T1 mapping value. The data were analyzed using R1 values (R1=1/T1), and the cut-off values were calculated using the receiver operating characteristic (ROC) curve.

Results: The R1 value of the pancreatic transection site in the POPF (+) group was significantly higher than that in the POPF (-) group (1.180 vs. 1.066 sec-1; P<0.001). The R1 value of the pancreatic transection site was an independent risk factor for grade B/C POPF (odds ratio, 5.01; P=0.005). To predict POPF, a cutoff R1 value of 1.116 sec-1 at the transection site was obtained by maximizing the Youden index.

Conclusions: High R1 values at the pancreatic transection site indicate a higher possibility of developing grade B/C POPF. Preoperative MRI T1 mapping may be valuable for predicting POPF after DP.