Role of power Doppler techniques and ultrasound contrast enhancement in the differential diagnosis of focal breast lesions.

The purpose of this article is to demonstrate the diagnostic impact of ultrasound in differentiating focal breast lesions with special regard on power Doppler and US contrast agents. The sonographic evaluation of breast lesions has become a standard procedure during the past 15 years. Especially the improvement of B-mode resolution and the use of high-frequency probes increased the diagnostic value of US. Assuming that the neoangiogenetic vascular architecture of solid breast lesions can be depicted reliably by color Doppler, many authors tried to differentiate between benignity and malignancy using Doppler criteria such as flow and morphologic aspects. Additionally, adjuvant techniques, such as harmonic imaging and new US contrast agents, are meant to be success-promising tools. Whereas the sensitivity and specificity of color Doppler have varied in different studies, prognostic prediction and treatment monitoring seem to be the future areas of application. To evaluate sufficiently flow signals of very small vessels with low flow velocity, the use of contrast-enhancing agents may be necessary. Nevertheless, an indispensable condition for successful Doppler-based assessment of the entity of breast lesions is the standardization of techniques, evaluation, analysis and weighting of the parameters.