A CT scan is a radiological imaging test that creates detailed images of the body, according to Medline Plus. It may be used to diagnose an infection, guide a surgeon to the correct area throughout a biopsy, identify masses or tumors within the body, or examine blood vessels.
CT scans are performed by a CT scanner, according to Medline Plus. This imaging machine rotates around patients while shooting X-ray beams toward them. A computer that is connected to the machine then creates separate slices, or images, of the body. A doctor can thread the slices together to examine the different structures of the body.
Some doctors may also use CT scans during surgery to help guide small needles through the body when performing biopsies or draining an abscess, explains WebMD. CT scans are not painful, but they may cause anxiety for some people who suffer from claustrophobia because the scans require patients to lie completely still in an enclosed space. In these cases, a doctor may administer a light sedative to calm a patient's nerves to make the procedure more comfortable. Because of the very high dose of radiation involved with a CT scan, doctors must inquire if a patient is pregnant before performing the test.