Ultrasonography, commonly called sonography, is a diagnostic medical procedure that uses high frequency sound waves (ultrasound) to produce dynamic visual images of organs, tissues, or blood flow inside the body. This type of procedure is often referred to as a sonogram or ultrasound scan. Ultrasonography can be used to examine many parts of the body, such as the abdomen, breasts, female reproductive system, superficial structures, prostate, heart, and blood vessels.

Ultrasonography is increasingly being used in the detection and diagnosis of heart disease, heart attack, and vascular diseases that can lead to stroke. It is also used to guide a fine needle, for tissue biopsy and amniocentesis, and to assist in taking a sample of cells from an organ or structure for lab testing (for example, a test for cancer in breast tissue and fetal growth in uterus).