Improved diagnosing of small hepatocellular carcinomas by echo-enhanced power Doppler sonography in patients with cirrhosis.

BACKGROUND AND AIMS

Echo-enhanced power Doppler sonography is an increasingly used procedure for the differentiation of liver tumours. The aim of this prospective study was to investigate the accuracy of echo-enhanced power Doppler sonography in comparison with conventional ultrasound and fundamental power Doppler sonography in diagnosing hepatocellular carcinomas and regenerative nodules in patients with cirrhosis.

SUBJECTS AND METHODS

Eighty-seven patients with cirrhosis and 90 liver tumours at conventional ultrasound were included in the study, selected from 103 consecutive patients with a mean age of 60 years (range 23-87 years) who presented to our department from January 1998 through January 2002. Sonography was performed by an experienced examiner, who was unaware of the clinical diagnosis. The exact diagnosis was based upon histological evidence from biopsy examination, laboratory results, and/or a follow-up of at least 18 months.

RESULTS

There were 65 hepatocellular carcinomas, 21 regenerative nodules, and four metastases in the study group. Only 43% of the carcinomas (mainly nodules > 3 cm in diameter) could be classified correctly by conventional ultrasound or fundamental power Doppler sonography. However, 46% of the malign lesions (mainly nodules < 3 cm in diameter) were not differentiable. All non-differentiable tumours were classified correctly by echo-enhanced power Doppler sonography. The overall sensitivity of echo-enhanced power Doppler sonography with respect to diagnosing hepatocellular carcinoma was 89%; its specificity was 60%. The corresponding values for regenerative nodules were 71% and 100%, respectively.

CONCLUSIONS

Only hepatocellular carcinomas greater than 3 cm in size can be diagnosed with a high accuracy by conventional ultrasound or fundamental power Doppler sonography. However, small malignant lesions in cirrhotic livers are often not differentiable with these techniques. With echo-enhanced power Doppler sonography, the differentiation of small hepatocellular carcinomas can be improved. However, histology is the standard of reference.