A scan is a medical test that uses X-rays, MRIs (magnetic resonance imaging), CT (computed tomography) scans, or ultrasounds to create pictures of the inside of your body. The type of scan you have will depend on what your doctor is looking for and the part of your body being examined.
For example, an MRI can show detailed images of soft tissues, while a CT scan can create cross-sectional views of hard tissues, such as bones. An ultrasound uses sound waves to produce images, and is often used to examine unborn babies or organs in the abdomen.
Scans are generally safe and don’t require any special preparation, although you may be asked to drink contrast material before a CT scan or MRI. Contrast material helps highlight certain structures on the image.
Some scans may be uncomfortable because you have to lie still for long periods of time. If you have claustrophobia (a fear of enclosed spaces), you may want to ask your doctor about sedatives before having the test.