Evaluation of hypervascular hepatocellular carcinoma in cirrhotic liver by means of helical CT: comparison of different contrast medium concentrations within the same patient.

PURPOSE

To compare enhancement of the aorta, portal vein, liver, and tumor with contrast medium of a higher iodine concentration to that with one of a standard iodine concentration for liver dynamic CT within the same patient with known liver cirrhosis and hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Fifty-three patients with known cirrhosis and HCC underwent repeat computed tomographic (CT) examinations within three months, the first with either 300 (n=26) or 370 mgI/ml (n=27) of nonionic contrast material. In the second examination, only concentration was altered. In 28 patients, weight was equal to or more than 65 kg, and in 25 patients it was less than 65 kg. The CT numbers (HU) of the aorta, portal vein, liver, and tumor were obtained, and CT attenuation was compared between the two concentration studies. The degree of enhancement was scored qualitatively.

RESULTS

Mean enhancement values of the aorta, liver, portal vein, and tumor were greater with the 370 mgI/ml injections than with the 300 mgI/ml injections throughout the study. In visual analysis, the difference in aortic, portal venous, liver, and tumor enhancement was not statistically significant between the two groups in patients weighing less than 65 kg. However, in patients weighing 65 kg or more, strong aortic and portal venous enhancement (rated as good or excellent) occurred more frequently with the 370 mgI/ml injections than with the 300 mgI/ml injections.

CONCLUSION

Higher contrast enhancement was achieved in patients who received 370 mgI/ml of contrast material, resulting in better tissue contrast between liver parenchyma and HCCs. However, this difference was not visually significant in patients weighing less than 65 kg.