Power Doppler ultrasonographic diagnosis of small hepatocellular carcinomas

Abstract

Background/aims: Power Doppler ultrasonography can evaluate the hemodynamics of intrahepatic tumors. The ability of power Doppler ultrasonography to detect small hepatocellular carcinomas and estimate the differentiation of the tumor by the patterns of intranodular waves was assessed.

Methods: We used conventional B-mode ultrasonography, power Doppler ultrasonography, and dynamic computed tomography to examine 71 hepatocellular carcinomas (</=3 cm) before liver resection.

Results: The sensitivity of conventional ultrasonography, power Doppler ultrasonography, and computed tomography increased as tumor diameter increased, with little difference between modalities. Nodules up to 5 mm in diameter as well as some nodules in the lateral segment or the subphrenic area of the liver were not detected by power Doppler ultrasonography, although two nodules not detected by computed tomography were apparent from power Doppler ultrasonography. With the latter modality, the proportion of nodules with afferent pulsatile waves was higher in moderately or poorly differentiated hepatocellular carcinomas than in well-differentiated hepatocellular carcinomas. Afferent continuous waves were detectable only in well-differentiated hepatocellular carcinomas.

Conclusion: Although the sensitivity of power Doppler ultrasonography remains unsatisfactory for minute lesions (</=5 mm) and for laterally or subphrenically situated lesions, this method can usually distinguish moderately or poorly differentiated from well-differentiated hepatocellular carcinomas, which is useful in planning treatment and predicting outcome.