Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Ultrasound imaging, also called sonography, produces images of the inside of the body using sound waves using a small transducer (probe) and ultrasound gel placed directly on the skin. High-frequency sound waves are transmitted from the probe through the gel into the body. The transducer collects the sounds that bounce back and a computer then uses those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in x-rays), thus there is no radiation exposure to the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.
Doppler ultrasound is a special ultrasound technique that allows the physician to see and evaluate blood flow through arteries and veins in the abdomen, arms, legs, neck and/or brain (in infants and children) or within various body organs such as the liver or kidneys.
Ultrasound is frequently used to help physicians evaluate symptoms such as pain, swelling, and infection. The most common ultrasound exams are of the thyroid, carotid arteries, abdomen, pelvic & scrotal, extremities, and OB (pregnancy).
Ultrasound is also used to guide procedures such as needle biopsies, in which needles are used to sample cells from an abnormal area for laboratory testing, image the breasts and guide biopsy of breast cancer, and diagnose a variety of heart conditions (commonly called an echocardiogram or echo for short), including valve pathology, congestive heart failure, and to assess damage following a heart attack.