Multiple-detector computed tomographic angiography of pancreatic neoplasm for presurgical planning: comparison of low- and high-concentration nonionic contrast media.

Objective: To evaluate the degree of contrast enhancement, image quality, and accuracy of predicting resectability of pancreatic neoplasm with 16-row multiple-detector computed tomography (MDCT) angiography using low- and high-concentration (300 and 370 mg of iodine per milliliter, respectively) contrast media (CMs).

Materials And Methods: Forty patients who had undergone pancreatic CT angiography (CTA) on 16-MDCT scanner and had surgery were included. Contrast medium of 2 iodine concentrations (group A, 300 mg/mL, n = 20; group B, 370 mg/mL, n = 20) from the same vendor (Isovue; Bracco Diagnostics), with iodine dose of 550 to 600 mg/kg of body weight, was injected at a rate of 5 mL/s. Dual-phase 16-row MDCT was performed using 1.25- and 5-mm collimation for the arterial and portal phases, respectively. For the quantitative analysis, Hounsfield units values in the aorta, superior mesenteric artery, portal vein, and pancreas during arterial and venous phases were measured. Two readers subjectively rated the overall image enhancement, 3-dimensional image quality, and lesion and pancreatic duct conspicuity. Accuracy of lesion resectability was also established for each patient. The data were compared using Student t test for statistical analysis.

Results: The quantitative analysis for the degree of enhancement (Hounsfield unit) of the aorta, superior mesenteric artery, and pancreas during the arterial phase demonstrated similar values in groups A (low-concentration CM) and B (high-concentration CM), with no statistically significant difference with each other (P > 0.05). During the portal venous phase, we found superior enhancements in the superior mesenteric and portal veins in group A (P < 0.05). The qualitative assessments of the overall image enhancement and 3-dimensional image quality on a 5-point scale were 4.3 and 4.65, respectively (P < 0.05), in group A and 4.6 and 4.75, respectively, in group B, whereas on a 3-point scale, the pancreatic duct display and lesion conspicuity were 2.75 and 2.85, respectively, in group A and 2.9 and 2.9, respectively, in group B. The accuracy for lesion resectability was 95% (19/20) in group A and 100% (20/20) in group B (P > 0.05).

Conclusion: Both CMs demonstrated comparable performance for 16-row MDCT of the pancreas for presurgical planning. However, high-concentration CM (370 mg of iodine per milliliter) provides higher overall enhancement and superior-quality 3-dimensional images with a shorter injection duration.