Breast Ultrasound Technology
The role of US is great in definition of breast masses in the areas that are technically difficult to examine with other imaging methods (e.g., on the margin of medial quadrants near the breastbone, in aberrant mammary lobes). US is unique for the analysis of the whole-breast vascularity and vascular pattern of its lesions. Additionally, US precisely characterizes abnormal lymph nodes. Breast US is performed with linear probes with the frequency of 5–12 MHz. Retromammary space is better examined with a 5.0 MHz probe and the nipple and areola with 10 MHz or higher frequency probe. The most common causes of errors in the diagnosis of breast cancer are small tumor size, tumor development on the background of diffuse adenosis, fibrous stellate bands, multiple small cysts with dense contents, perifocal inflammation, etc. Lymph nodes, which are adjacent to the breast, often cause difficulties in correct diagnosis. The conclusion of breast lesion is only permitted in the case of its clear demonstration at least in two perpendicular projections. Auxiliary methods, such as lifting of patient’s arms, turns of the body to one or another side, and change of body position, are important for differential diagnosis. Correct diagnosis sometimes requires long follow-up or application of other diagnostic methods.