Pancreatic adenocarcinoma: a comparison of automatic bolus tracking and empirical scan delay

Abstract

To evaluate the efficacy of automatic bolus tracking in multidetector row CT (MDCT) for pancreatic adenocarcinoma as compared with standard scan delay using the fixed duration contrast injection technique. Seventy-nine patients with pancreatic adenocarcinomas underwent three-phase enhanced CT with an individualized scan delay as determined by automatic bolus tracking (protocol 1) or an empiric scan delay (protocol 2). We evaluated enhancement of the aorta, portal vein, hepatic parenchyma, pancreatic parenchyma, and pancreatic adenocarcinoma during each phase. Two radiologists graded the conspicuity of pancreatic adenocarcinoma in the pancreatic parenchymal phase. The results for the different groups were statistically compared. Pancreatic parenchymal enhancement (mean ± standard deviation, 100.2 HU ± 17.6 vs. 88.5 HU ± 22.1; P < 0.05) and tumor-to-pancreas contrast (mean ± standard deviation, 75.3 HU ± 25.0 vs. 63.1 HU ± 24.1; P < 0.05) were significantly greater in protocol 1 than in protocol 2 during pancreatic parenchymal phase. Qualitative results correlated well with quantitative results (reviewer 1: R (s) = 0.78, P < 0.001; reviewer 2: R (s) = 0.66, P < 0.001) The use of automatic bolus tracking with MDCT can significantly improve the degree of contrast enhancement in the pancreatic parenchyma and tumor-to-pancreas conspicuity.