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

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.