Ultrasound: unsung medical hero.

• Author: McDonagh, D. Brian

ASK THE AVERAGE person about top breakthroughs in medical history, and diagnostic ultrasound probably will not be mentioned. It should be. Ultrasound can diagnose ailments, assist in treatments, and also is a therapy in and of itself. Ultrasound is perhaps the most diverse technology available today.

Cardiologists have been using it for decades to help assess the health of patients' hearts. News of ultrasound spread to the general public in the 1970s, when obstetricians used it with great frequency to monitor fetal development. Doctors could learn the size of the fetus, identify any growth problems or abnormalities. and even give parents a sneak preview of the baby's sex. At that time, other applications still were only a vision. Obstetricians frequently use ultrasound to get valuable information, including:

* The number, size, and age of fetuses in the uterus. Age can be determined by measuring the length of the fetus or the length of the thigh bone and the circumference of the head.

* Location of the fetus or placenta. which is helpful in the delivery of breech babies or during amniocentesis.

* Fetal movement, breathing, and heartbeat.

* Amount of amniotic fluid in the uterus, an aid in the assessment of fetal health.

Recent improvements in ultrasound's image quality, combined with its ease of use, has catapulted this technology into almost every branch of medicine. Ultrasound provides instant displays of organs that are more accurate than other imaging devices. It identifies organ abnormalities of soft tissue that can not be seen with X-rays. Most importantly, ultrasound is a noninvasive method that has no known risks and spares many patients the trauma and pain of exploratory surgery.

One way physicians use ultrasound to see inside the patient's body is with a procedure known as pulse-echo imaging. A microphone-like device, known as a transducer. is moved across the skin over the part of the body the doctor needs to view. The transducer emits sound waves (ultrasound) that, when they bounce off various tissues and organs. generate distinctive echoes that are conveyed to a computer. The computer translates the timing and strength of these echoes into an image of the internal organs or tissues targeted by the ultrasound beam. The ultrasound image, or sonogram, usually is viewed on a television screen.

Ultrasound imaging is an excellent tool for examining organs to check for any internal abnormalities and probing tissues for tumors, cysts...