An ultrasound creates images of the breast in the same way it shows pictures of developing babies in pregnant women. High-frequency sound waves are transmitted from a transducer (a device that resembles a microphone) through the breast. The sound waves make echoes as they bounce off various types of tissue. A computer converts the echoes into an image that is displayed on a video monitor.
Receiving an ultrasound is painless. While lying on a table, the ultrasound technician will cover the part of the breast to be examined with a gel. This lubricates the skin and helps to transmit the sound waves. The technician will then guide the transducer back and forth across the breast until clear images have been generated and captured for analysis. The breast exam usually lasts between 20 and 30 minutes.