Breast examinations with continuous wave and color Doppler.
Continuous wave Doppler has been used for many years to characterize malignant breast lesions. With continuous wave Doppler pencil probes, operating at frequencies between 8 and 10 MHz, 94% of the carcinomas have shown abnormal vascularity. Flow assessment with continuous wave Doppler alone is only possible in palpable lesions. We have improved the diagnostic accuracy by combining continuous wave Doppler and B-mode ultrasound which allows for flow detection in non-palpable lesions. This procedure is rather complicated, because of sound interference, and requires a good deal of experience. Ultrasound equipment with color flow mapping has been available for several years. However, during the last 3 years, the sensitivity of the instruments has been improved, allowing the detection of flow in microscopic vessels which are not visible in B-mode scanning. Evaluation of this method is difficult, as the sensitivity of color Doppler equipment shows remarkable variations. In order to evaluate the capability of color Doppler for investigation of abnormal blood flow in breast malignancies, we examined 120 symptomatic women using different types of equipment and compared the findings to those of continuous wave Doppler. In ten of 44 carcinomas, no color flow signals were found. However, continuous wave Doppler showed low vascularity in all of these ten false-negative cases. Among the remaining patients with benign disease, no false-positive reports were made. The major difficulty in flow assessment with color Doppler was the heterogeneous vascularity of breast malignancies. When a low Doppler frequency (<or= 5 MHz) is used, signals may not be detected from poorly vascularized cancers.
Madjar
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University of Freiburg, Department of Gynecology and Obstetrics, Freiburg, Germany.