Prediction of postoperative pancreatic fistula based on multi-sequence MR imaging

To investigate the value of conventional MRI sequences in predicting the occurrence of postoperative pancreatic fistula (POPF) in patients undergoing pancreaticoduodenectomy (PD).

A total of 122 patients from August 2019 to April 2023 were enrolled. All patients underwent pancreatic histological evaluation, including fibrosis, fat deposition, and acinar cell atrophy. The preoperative image features of pancreas were obtained, including morphological features, pancreas-muscle signal intensity ratio, pancreatic fat fraction and multi-phase enhancement features. The patients were divided into two groups according to whether pancreatic fistula occurred after operation. The related risk factors of pancreatic fistula, the correlation between imaging and pathological changes were analyzed, and the value of preoperative imaging in predicting pancreatic fistula was evaluated.

Of the 122 patients, 23(18.9 %) developed POPF. Pathological score showed that there was a significant difference in pancreatic fat deposition between the two groups (P = 0.006), the fat deposition score was higher in the POPF group. Pancreatic fat deposition was the only independent risk factor for POPF(OR,1.933; P = 0.018). MRI showed that proton density fat fraction(PDFF) (P = 0.001), pancreas-to-aorta signal intensity ratio(P-A SI ratio) of equilibrium phase(P = 0.023) and delay phase(P = 0.020) had significant differences. PDFF was positively correlated with fat deposition(r = 0.404, P < 0.001), P-A SI ratio of equilibrium phase and delay phase were positively correlated with fibrosis(r = 0.313, P = 0.002; r = 0.315, P = 0.002, respectively). ROC analysis showed that PDFF had the best efficacy in predicting postoperative pancreatic fistula (AUROC = 0.810), better than P-A SI ratio of equilibrium phase(AUROC = 0.752) and delayed phase(AUROC = 0.766).

Pancreatic fat deposition is a high risk factor for POPF, PDFF can reflect fat deposition and predict POPF.