Ultrasound or sonography involves the transmission of sound waves into the body. Those sound waves are reflected off the internal organs. The reflections are then recorded by special instruments that subsequently create an image of anatomic parts. No ionizing radiation (x-ray) is involved in ultrasound imaging.

For women, pelvic ultrasound is most often used to examine the uterus and ovaries and, during pregnancy, to monitor the health and development of the embryo or fetus. In men, a pelvic ultrasound usually focuses on the bladder and the prostate gland. Ultrasound images are captured in real-time, so they can show movement of internal tissues and organs, such as the flow of blood in arteries and veins.