[Doppler and color Doppler ultrasound diagnosis in differentiation of focal liver lesions].

The frequent detection of benign liver lesions during ultrasound routine examination and a possible curative therapy of early detected malignant tumors require a reliable method of differentiation. Conventional gray-scale ultrasound, according to this problem, has been extended by the Duplex technique and color Doppler ultrasound. Measurement of blood flow velocity by Doppler in the center and at the periphery of liver lesions is not reliable enough to distinguish between benign and malignant lesions. Color Doppler ultrasound possesses some reliable criteria for differentiation. A central spot could be detected in 2 out of 12 hemangiomas, a giant spot in 1 out of 3 giant cavernous hemangiomas. The halo sign without detectable blood flow is considered to be specific for malignancy. We found this sign in 26 out of 81 malignant liver lesions and only in one benign lesion (sensitivity 32%, specificity 97%). The vascularization of focal liver lesions is excellently demonstrated with color Doppler ultrasound. This is very helpful for the diagnosis (e.g. "chaotic blood vessel architecture' in malignant tumors) and for the therapy of focal liver lesions (e.g. follow-up examinations after chemotherapy or chemoembolization). Therefore, application of Duplex and color Doppler ultrasound is highly recommended as a noninvasive diagnostic method of first choice for unknown liver lesions.