Ultrasound (USG) or sonography involves the sending of sound waves through the body. Those sound waves are reflected off the internal organs. The reflections are then interpreted by special instruments that subsequently create an image of anatomic parts. No radiation is involved in ultrasound imaging.
Ultrasound is useful in detecting various musculoskeletal disorders such as tendon tear and inflammation, soft tissue masses and joint lesions. It is also useful in detecting various congenital lesions of the brain, useful in obst.-gynec imaging, pelvic ultrasound examinations of the uterus and fetus. Ultrasound imaging is used extensively for evaluating the eyes, heart, and blood vessels, and can help a physician determine the source of pain, swelling, or infection in many parts of the body. It can also be used to guide procedures such as needle biopsies, Ultrasound is now being used to image the breasts and to guide biopsy of breast cancer.
Doppler ultrasound is a special technique used to examine blood flow. Doppler images can help the physician to see and evaluate: blockage of blood flow, such as clots, build-up of plaque inside the vessel, congenital malformation.
Ultrasound imaging is a painless, low cost examination, widely available and easy to use. US imaging uses no radiation, and is the preferred image modality for diagnosis and monitoring of pregnant women and their unborn infants.