Vascular involvement and resectability of pancreatic ductal adenocarcinoma on contrast-enhanced MRI: comparison with pancreatic protocol CT.

purposeTo compare the diagnostic performance for detecting vascular involvement and determining resectability differences regarding pancreatic ductal adenocarcinoma (PDAC) between contrast-enhanced CT and MRI.

methodsThis retrospective study evaluated 82 patients (73 years, 46 men) with PDAC who underwent both preoperative contrast-enhanced CT and MRI from January 2008 to March 2021. Two radiologists independently categorized vascular involvements for celiac, superior mesenteric, splenic, and common hepatic arteries, and portal, superior mesenteric, and splenic veins into no tumor contact, solid soft-tissue contact ≤ 180°, or solid soft-tissue contact > 180°. The radiologists also classified resectability into resectable, borderline resectable, or locally advanced. Receiver-operating-characteristic (ROC) analysis was conducted to evaluate the diagnostic performances for detecting vascular involvements which were confirmed by pathological or intraoperative findings. The proportion of resectability classifications was compared between CT and MRI by the Fisher's exact test.

resultsNo statistical difference was found in the diagnostic performances for detecting vascular involvement in CT (area under the ROC curve [AUC], 0.50-0.89) and MRI (AUC, 0.51-0.75) (P = 0.06-> 0.99). Resectability on CT were 79% and 68%, 20% and 26%, and 1% and 6% for resectable, borderline resectable, and locally advanced tumors for reviewers 1 and 2; those on MRI were 87% and 81%, 12% and 13%, and 1% and 6%, respectively. The proportion of resectability classifications was not different between CT and MRI (P = 0.48 and = 0.15 for reviewers 1 and 2, respectively).

conclusionThe diagnostic performance for detecting vascular involvement and determining resectability of PDAC on contrast-enhanced MRI were comparable with pancreatic protocol CT.