An ultrasonography (or sonography) is a diagnostic medical procedure that uses high frequency sound waves to produce images of organs, tissue and blood vessels within the body. A transducer which can emit and receive high frequency sound waves is placed on the area to be tested. The sound waves bounce back from the internal organs and form an image on a computer screen. The resultant image, which is available in 3D and 4D forms too, is known as a sonogram.
Ultrasonography is used to detect any abnormalities in the abdomen, breasts, heart, blood vessels, reproductive organs (ovaries, prostate etc.) and for pregnant mothers. It is also used to help guide procedures like a needle biopsy (where abnormal tissue is removed from the body), if there is any suspicion of a blood clot in a blood vessel, tumours, congenital malformations, and for procedures like the Doppler analysis.