Gray scale ultrasound
Ultrasound is essential for the clinical examination and mammography, not only useful in differentiating cystic lesions from solids, but also in additional characterization of breast masses. The vast majority of breast masses with an opacity aspect greater than 5 mm on mammography images can be viewed through ultrasound if the doctor has enough experience in breast ultrasound and if he is using high performance devices.
Breast ultrasound became an increasingly used diagnostic method in senology services. In evaluating breast lesions, ultrasonography is considered complementary.
Most breast neoplasms can be detected by both methods; some others can be viewed only through ultrasound or mammography. Ultrasound is a widely available imaging method, noninvasive and efficient that can be applied in any period of the menstrual cycle, it is often performed after clinical examination and mammography.
Usefulness of ultrasonography include evaluation of:
- Injuries found on clinical examination or mammography
- Breast in women under 30 years (the first intention examination)
- Dense breast (opaque in mammogram)
- Impalpable lesions that appear as nonspecific mammographic images
- Peripheral formations that can`t be examined through mammography
- Changes detected during pregnancy or during lactation.
For lumps, the ultrasound is useful in guiding interventional maneuvers; it contributes to disease staging (presence and character of lymph nodes) and to repeated check-up of their evolution under treatment.
Using Doppler ultrasound of the breast was first described by Wells in 1997. Devices with high resolution and sensitivity to slow flows have made the use of the Doppler ultrasound in the study of mammary gland pathology possible, also allowing vascular signal detection in the normal breast parenchymal.
Continuous Doppler ultrasonography method was the first to revealed some subtle changes in blood flow of the breast depending on the menstrual cycle and demonstrated the symmetry of these changes on most women.
The most common method in research of blood flow of the mammary focal lesions is color Doppler ultrasound. This allows the identification of blood vessels that can`t be viewed in gray scale technique.
Power Doppler ultrasound or angioultrasonography uses a fundamentally different physical parameter from pulsed Doppler. This technique analyzes the reflected signal amplitude and not its frequency, practically estimating the volume of the blood cells in motion and not their speed. The sensitivity of this method is considerably higher for slow flows, lowest speeds detected reaching 0.4 mm / sec.