Depiction of hypervascular hepatocellular carcinoma with 64-MDCT: comparison of moderate- and high-concentration contrast material with and without saline flush

Abstract

Objective: The purpose of this study was to evaluate prospectively the depiction of hypervascular hepatocellular carcinoma on 64-MDCT scans obtained with contrast agents of varying iodine concentrations administered with and without saline flush.

Subjects and methods: The study included 149 patients, among whom 36 patients with hypervascular hepatocellular carcinoma were identified. Patients were randomly assigned to one of three protocols: A, contrast material of 300 mg I/mL; B, 370 mg I/mL; C, 370 mg I/mL plus saline flush. In all protocols, the same iodine load per kilogram of body weight (516 mg/kg) was administered for the same injection duration (30 seconds). Enhancement values in the aorta, liver, and portal vein and tumor-liver contrast were measured at multiphase CT.

Results: Aortic enhancement was significantly different between protocols A and B (p = 0.04, p < 0.0001) and protocols B and C (p = 0.02, p < 0.001) in the first and second phases. Portal venous enhancement was significantly different between protocols B and C (p = 0.02) in the first phase and between protocols B and C and protocols A and C (p < 0.01, p = 0.02) in the second phase. Tumor-liver contrast was significantly different between protocols A and B (p = 0.03, p = 0.02) and protocols B and C (p = 0.03, p = 0.04) in the first and second phases but not between protocols A and C. There was no significant difference in hepatic enhancement among the three protocols.

Conclusion: Use of moderate concentration was more effective than use of a high concentration of contrast material for depiction of hepatocellular carcinoma. Adding a saline flush to the high-concentration protocol eliminated the difference in depiction of hepatocellular carcinoma between the moderate- and high-concentration protocols.