In an ultrasound exam, high-frequency sound waves are used to produce internal images of your body. Ultrasound technology is based on using sonar the same way a bat or submarine uses sound waves to identify objects and distances.
The exam is conducted by placing a "transducer" or "wand" on the area of your body the doctor wants to see. The wand is connected to a scanner and sends sound waves out across your body that are reflected back to the wand from different body tissues. The soundwaves are transmitted from the wand to the ultrasonic scanner and an image of your internal body structure is produced. This is the same technology used to check on a baby's development before birth and often, to determine the sex of the child before he or she is born!
Ultrasound examination is fast, painless and noninvasive. Ultrasound is used in the diagnosis and treatment of a wide variety of medical conditions.
Ultrasound can be used to examine organs (or conditions) in your abdomen that can include:
- Monitoring the success of a kidney transplant
Ultrasound can detect and monitor problems with your blood vessels:
- Enlargements in vessels
- Blood clots
- Narrowing of arteries
A gynecologist or radiologist may use ultrasound to:
- Look at images of the uterus and ovaries
- Monitor fetus development
- Detect the source of pelvic pain
- Diagnose bleeding problems
Ultrasound is sometimes used to detect tumors or determine a change in their size and shape. Depending on the type of cancer, an ultrasound can:
- Help doctors locate lumps or masses
- Help distinguish between cysts and tumors
- Help doctors know where to insert a needle to obtain a biopsy
- Help monitor the success of cancer treatment
What to expect when you have an ultrasound
The instruction you receive will depend on the type of test you are having. If you are having an abdominal ultrasound, you will probably be asked not to eat or drink eight hours before your test. Other exams do not require any preparation. You will be most comfortable wearing loose fitting clothing and you may be asked to change into a gown.
Ultrasounds are painless, noninvasive exams. Before the exam starts, a gel will be applied to your skin over the area being examined. The gel improves the ability of sound waves to pass from the wand through your skin.
The wand is moved back and forth on the skin and images produced by the sound waves are transmitted onto a monitor. Depending on the type of exam, you may have to lie still, change positions or hold your breath.
To produce images of a woman's pelvic area, specially designed wands may be inserted into the vagina. In a transrectal ultrasound, a smaller wand is inserted into the rectum.
After the exam
After the exam the gel will be wiped off your skin and you will be free to go about your day. Your ultrasound images will be studied by a radiologist and the results will be sent to the physician who requested the test. Your doctor will discuss the exam results with you.