CT scan is a diagnostic imaging procedure that combines the use of X–rays with computer technology to produce cross–sectional images of the body. The images produced by this scan are more detailed than those of an ordinary X–ray. A thin cross section of the body, i.e. a tomography is examined from multiple angles with a thin beam. After the beam passes through the body, the transmitted radiation is picked up by a series of detectors, fed into a computer for analysis by a mathematical algorithm and reconstructed as a tomographic image.As a result, the entire body can be visualized in a series of cross–sectional images. CT scanning produces clear, detailed images of all structures (bone muscle, fat, and organs) in the part of the body being examined.
- Tumors of various parts of the body.
- Bleeding or injuries.
- After an accident to check for damage to internal body structures.
- During a CT scan, the patient lies still on a table.
- He or she removes all jewelry and metal items.
- The table slides into the CT unit, which is like a small tunnel.
- It is important not to move during the scan, although you may breathe normally.
- The scanner rotates around the table and may make clacking noises.
- Communication is maintained throughout the procedure.
- If a person becomes panicky the procedure may be stopped at any time. Some people have a fear of enclosed spaces.
- The doctor may give a mild sedative to restless or anxious people.
- Prior fasting for 3–4 hours is essential in all scans where IV contrast is to be administered.
- All scans related to abdomen and pelvis need opacification of the bowel (large and small) 20–30 minutes before commencing the study. This is done by asking the patient to drink 6–7 glasses of a flavored drink which contains a contrast material.
- Other scans not requiring any IV/oral contrast do not require any specific preparation.
Common Indications for CT Scans
Side Effects of CT Scan
Scanning typically lasts from 30 to 90 minutes. It is painless. The person may receive an injection of dye to create contrast. If so, the person is instructed to fast for 4 hours before the test. Some people are sensitive to the contrast dye. The dye may cause warm feelings, flushed face, temporary headache, salty taste, or nausea and vomiting.