A CT (computed tomography) scan uses special X-ray equipment to take multiple images from different angles around the body. A computer then processes the information from the images and produces an image that shows a cross section of the area being examined. To help visualize the process, imagine looking at one end of a loaf of sliced bread. If you pull a slice out of the loaf, you can see the entire surface of that slice, from the outer crust to the center. The body is seen on CT scan “slices” in a similar way, from the outer skin to the central part of the body. The exam produces multiple slices showing multiple views of the area being examined. The “slices” can be displayed on a video monitor and saved on film for analysis. A spiral or helical CT involves CT equipment that moves around the patient in a spiral path, allowing continuous data with no gaps between images. The image can be made even clearer by using a special contrast agent, which can be swallowed as a liquid, injected into a vein, or given as an enema. Examples of Uses: CT scans can be used to view, monitor, or diagnose
- muscle and bone disorders, such as tumors and fractures
- diseases such as cancer or heart disease
- tumors, infections, or blood clots
- internal injuries
- are or may be pregnant
- become anxious in confined spaces
- are allergic to the contrast agent
- are allergic to any substance with iodine
- have been diagnosed heart failure, diabetes, or kidney problems
- CT scans offer detailed views of many types of tissue, including bone, soft tissue, blood vessels, and lungs.
- CT scans are painless, non invasive, and fast.
- Scans can identify normal and abnormal structures, making them a useful tool to guide radiotherapy, needle biopsies, and other minimally-invasive procedures.
- CT has been shown to be a cost-effective tool for a wide range of clinical problems.
Risks:CT scans involve exposure to radiation in the form of X-rays. The amount of radiation exposure is variable depending upon the scan type (for example, a scan of the brain, lungs, or abdomen) and the scanner type (for example, different models and manufacturers). Because the radiation exposure is variable, the risks are also variable. Speak to your radiologist, or your physician who refers you for the CT scan, for specific details about possible radiation exposure risks.
- There is a rare risk of a major allergic reaction to the contrast agent.
- CT scans may involve additional risks if:
- You are or may be pregnant and the scan is of your abdomen. Your doctor may recommend another type of test to reduce the possible risk of exposing your baby to radiation.
- You have diabetes, asthma, allergies, heart disease, kidney problems, or thyroid problems.
- You are breast feeding. Nursing mothers should wait 24 hours after receiving the contrast medium before resuming breast feeding.
- You have already had several previous CT scans to the same part of your body.
Results:A radiologist, who is a physician with specialized training in CT and other imaging tests, will analyze and interpret the results of your CT scan and then send a report to your personal physician. It usually takes a day or so to interpret, report, and deliver the results. Contact your personal physician for information on the results of your CT.