Ultrasound, also called sonography, is a medical imaging method that uses high-frequency sound waves to create images of organs and systems within the body. The sound waves reflect off body structures. Then, a computer receives these reflected waves and uses them to create a picture.
Unlike certain other diagnostic imaging tests, like X-ray or CT scans, ultrasound does not use ionizing radiation.
How is an ultrasound performed?
During an ultrasound, you will lie down and a clear, water-based conducting gel will be applied to your skin over the area being examined. This gel helps with the transmission of the sound waves.
Then, a handheld probe, called a transducer, is moved over the area being examined. You may be asked to change your position during the test so other areas can be examined.
Why is the test performed?
Ultrasound is often used to:
- Monitor a fetus
- Study the heart
- Diagnose gallbladder disease
- Diagnose certain infections
- Diagnose certain types of cancer
- Evaluate flow in blood vessels
- Guide a needle biopsy
- Guide the biopsy and treatment of a tumor
- Check the thyroid
- Discover abnormalities in the scrotum and prostate