Value of new contrast harmonic technique for detecting tumor vascularity in hepatocellular carcinoma: Preliminary results.

Abstract

To investigate the value of a new wide-band contrast harmonic imaging method in depicting intratumoral vascularity in hepatocellular carcinoma. Twenty-two patients with 28 hepatocellular carcinoma nodules evaluated with Contrast Harmonic Echo, a new wide-band harmonic imaging method, using Levovist(®) as a contrast-enhancing agent. Intermittent imaging was carried out in the early arterial phase for 10 to 40 seconds, in the late vascular phase for 1 to 2 minutes, and in the postvascular phase for 5 to 7 minutes. Subtraction images were obtained using the multishot method during the late vascular phase. The ability of Contrast Harmonic Echo imaging to detect vascularity in hepatocellular carcinoma was compared to that of unenhanced color Doppler imaging by analzing results obtained using dynamic CT as a gold standard. Contrast harmonic Echo imaging detected intratumoral vessels, tumor parenchymal stain, and perfusion defect in the early arterial phase, the late vascular phase, and the postvascular phase, respectively. In the late vascular phase, the subtraction image clearly delineated the tumor parenchymal strain. Intratumoral vascularity was detected in 25 (89%) of the hepatocellular carcinoma nodules by Contrast Harmonic Echo, compared with 15 (54%) when color Doppler imaging was used (p<0.05). The diagnostic sensitivity, specificity, and accuracy of Contrast Harmonic Echo were 96.1%, 100% and 96.4%, respectively, corresponding to results obtained using dynamic CT. Contrast Harmonic Echo imaging is superior to unenhanced color Doppler imaging in depicting intratumoral vessels and parenchymal stain, and agrees closely with results obtained with three-phase dynamic CT.