[The correlation between Doppler echography with a contrast medium and CT in the study of a hepatocarcinoma submitted to chemoembolization].

PURPOSE

We report our preliminary experience concerning Doppler studies with the intravenous injection of a galactose-based echo contrast agent (SHU 508 A) in hepatocellular carcinomas (HCCs) treated with transcatheter arterial chemoembolization. We correlated US findings with those of iodized-oil helical CT.

MATERIAL AND METHODS

In 1997 we examined 18 patients with cirrhosis and HCC (31 nodules in all) submitted to hepatic oily chemoembolization 15-30 days earlier. The lesions were studied with color and power Doppler US before and after echo contrast agent infusion (300 mg/mL, injection/nodule, constant rate in 60-90 s) and with Lipiodol CT (0-7 days after US). In the retrospective analysis, special care was paid to Doppler signals from pulsatile intra- and perinodular flow and to the detection of new small vessels on enhanced images. The signal was graded as absent (0), weak (1), medium (2) and strong (3). The oily agent uptake on CT images was graded as absent (0), grade I (< 10%), II (< 50%), III (> 50%) and homogeneous (IV). All scores were given on a blind basis.

RESULTS

Liver enhancement was found in all cases and always lasted long enough to allow the accurate depiction of parenchymal lesions (at least 8 minutes). Signal intensity could be evaluated in 27 of 31 HCCs (2 were too deeply seated and two were too affected by cardiac activity). We had the following scores: basal color Doppler: grade 0 = 15 lesions, grade 1 = 8 lesions, grade 2 = 4 lesions; contrast-enhanced color Doppler: grade 0 = 11 lesions, grade 1 = 7 lesions, grade 2 = 8 lesions, grade 3 = 1 lesion; basal power Doppler: grade 0 = 12 lesions, grade 1 = 8 lesions, grade 2 = 6 lesions, grade 3 = 1 lesion; contrast-enhanced power Doppler: grade 0 = 10 lesions, grade 1 = 7 lesions, grade 2 = 8 lesions, grade 3 = 2 lesions; Lipiodol-CT: grade 0 = 1 lesion, grade I = 1 lesion, grade II = 7 lesions, grade III = 8 lesions, grade IV = 10 lesions. The difference between color and power Doppler scores, both compared to each other and between basal and enhanced images, never exceeded one.

CONCLUSIONS

Contrast-enhanced Doppler US is a simple and fast technique allowing strong, constant and long-lasting enhancement. Doppler US techniques permit the effective and realistic study of HCC nodules treated with chemoembolization and show a better correlation with Lipiodol CT than basal studies. Power Doppler is slightly more sensitive and accurate than color Doppler and shows a better correlation with Lipiodol CT.