ltrasound uses reflected sound echoes to study and characterize internal structures and tissues.

Many mothers are familiar with ultrasound as a diagnostic tool for examining the fetus during pregnancy. With ultrasound a growing fetus can be imaged, an achievement previously impossible without exposing the fetus to ionizing radiation.

During an obstetrical ultrasound, a series of measurements will be made to determine the age and overall health of the fetus. Ultra sound is also important to the nonpregnant woman as it may visualize abnormalities of the ovaries, fallopian tubes or uterus not detectable by clinical examination.

Another major application of ultrasound imaging is in the field of heart disease. Ultrasound is an excellent tool for examining the heart because it is "non-invasive" (not traumatic to the body) and can reveal more about heart function than conventional x-ray studies.

Cardiac ultrasound eliminates the need for many diagnostic procedures that require thin tubes, or catheters, to be inserted into the heart. Ultrasound is indispensable in detecting fluid collections around the heart and is the best technique for the diagnosis and follow-up of heart valve abnormalities.

Ultrasound can reveal information about the shape, texture and composition of tumors and cysts that cannot be seen on conventional x-ray studies. Suspicious lumps found during a mammographic study can be examined with ultrasound to determine whether they are benign cysts or solid masses. Some gallstones and kidney stones may be seen only with ultrasound; ultrasound is the imaging technique of choice for diagnosis of gallstones. An infants brain and spinal cord can be easily imaged by ultrasound. As the uses for ultrasound increase, it is providing new ways to image the musculoskeletal system and the prostate gland.