What is ultrasonography (ultrasound)?
Ultrasonography is a safe imaging test that uses sound waves to create a moving picture of the insides of your body. Ultrasonography doesn't use radiation (x-rays). Ultrasonography is also called ultrasound or sonogram.
Ultrasonography is painless and very safe, even if you’re pregnant
Ultrasonography can show moving parts of your body, such as your heart beating
IAN HOOTON/SCIENCE PHOTO LIBRARY
Why would I need ultrasound?
Doctors may use ultrasound to find growths in your neck, breasts, groin, arms, or legs. Ultrasound can help tell the difference between a cyst (fluid-filled sac) and a solid tumor. An ultrasound can also show problems with organs in your belly, hip (pelvic) area, and chest, such as:
Areas of your heart that are the wrong size or shape
Tiny stones or blockages in your gallbladder
Tumors
If doctors need to take a sample of a tumor or other growth, they can use ultrasound to help guide them.
If you're pregnant, doctors will often do ultrasound to see how your baby is growing and developing.
Special types of ultrasound for heart and blood vessel problems
Doppler ultrasound shows your heart and blood moving, so doctors can see:
Problems with the way your heart beats
Problems with the way blood flows through your blood vessels
Color Doppler ultrasound shows which direction your blood is flowing:
To your organs
To tumors or other growths
In your head and neck, to find out your chance of having a stroke
What happens during an ultrasound?
Before the test
If doctors are doing an ultrasound of your stomach area, they'll usually ask you not to eat or drink for several hours before the test. However, if they're doing an ultrasound of female organs (or in men the prostate), they may have you drink extra water to fill up your bladder.
During the test
You'll lie on a table
Doctors put a gel on your skin over the body part they want to see
They'll glide a small, hand-held device across your skin
The device sends sound waves into your body and records how the sound waves bounce off your internal organs
The sound waves are so high-pitched you can't hear them
A computer turns the sound waves into a still picture or a movie of the inside of your body
For some tests, doctors may insert the device into your body—for example, into your vagina to get pictures of your womb when you're pregnant, or into your rear end to get pictures of your prostate gland to look for cancer.
What are the problems with ultrasound?
Ultrasound waves don't cause any damage
Having the device put into your vagina or rear end is uncomfortable
Bone or gas can block an ultrasound
