Ultrasound is a painless, non-invasive test. A technologist spreads a layer of gel over the part of the body to be examined. The gel helps conduct the sound waves. The technologist then moves the transducer back and forth over the body. Images are viewed in black and white on a nearby screen. Depending on the reason for the test, it may take 20-60 minutes.
The radiologist, who is a doctor, will check to make sure the ultrasound images are usable. You'll usually be able to leave right after the test, and the images will be sent to your doctor.
You usually do not need to do anything special. If you are having an abdominal ultrasound, you should not eat or drink within eight hours of the appointment. For pelvic ultrasounds of the bladder, you should drink 32 to 40 ounces of water before the procedure. When your appointment is set up, your doctor can tell you what you will need to do.
If you have an allergy to latex or may be pregnant, be sure to let the technologist know when you arrive.