Ultrasonic Doppler studies of the breast.

The growth of a malignant tumour depends on vascularisation. The ultrasonic Doppler method can detect the blood flow associated with malignant breast tumours, the signals differing qualitatively from those due to benign lesions. Several descriptors of the Doppler signals were tested; benign and malignant lesions are best separated by the difference between the maximum systolic frequencies from suspect and contralateral sites. Corresponding main arterial sites are reliably coincident in normal breast pairs. Consideration of the powers and frequency spectra of Doppler signals leads to the rejection of models of tumour vascularisation giving Doppler signals based on capillary perfusion and on a single feed artery. The data are compatible with a multiple feed artery model, and this is supported by a contrast angiogram. Doppler ultrasound may be useful as a preliminary screening method, in the management of patients with radiologically dense breasts or diffuse dysplasia, and for monitoring unexcised tumours undergoing hormone therapy.