POSSIBILITY OF DIFFERENTIATING SMALL HYPERECHOIC LIVER-TUMORS USING CONTRAST-ENHANCED COLOR DOPPLER ULTRASONOGRAPHY - A PRELIMINARY-STUDY

We performed a preliminary study to investigate the possibility of dif ferentiating small hyperechoic liver tumours, including hepatocellular carcinomas (HCCs), haemangiomas and focal fatty lesions, by administe ring a galactose-based contrast agent (SH/TA-508 (Levovist)) during co lour Doppler ultrasonography (US). Ten patients (age range: 48-81 year s) with small liver tumours (four HCCs, four hemangiomas and two focal fatty lesions) of less than 20 mm in diameter presented with hyperech oic masses with no intratumoural colour signals on conventional colour Doppler US, All patients subsequently underwent colour Doppler US wit h this contrast agent. Colour Doppler images of the tumours mere asses sed before and after the intravenous injection of 8 ml of the contrast agent at a concentration of 400 mg/ml. Prior to injection of the cont rast agent, no intratumomal colour signals were observed in any cases, After injection, intratumoural colour signals appeared in all HCCs an d in two haemangiomas with tumour-margin enhancement. The enhanced col our signals appeared to be related to cardiac contraction in the HCCs, but not in the haemangiomas. In the remaining two haemangiomas, only tumour-margin enhancement was observed, In the focal fatty lesions, ne ither intratumoural nor tumour-margin enhancement was observed, These results, although preliminary, suggest that the detection of colour Do ppler signals is improved by using a contrast agent and the difference s between enhanced colour signals from HCCs and haemangiomas may help differentiate hyperechoic HCCs from other hyperechoic tumours, includi ng haemangiomas and focal fatty lesions.