What is a CT scan?
A CT scan is a special type of x-ray that looks at the different structures in the body such as the bones, lungs, lymph nodes, blood vessels and other organs. A CT scan provides cross-sectional pictures of the body in slices, like a loaf of bread. The detailed information provided in these slices can assist in the diagnosis of a wide variety of medical conditions.
How do physicians use a CT scan?
CT scans are often used to clarify an unusual or unexpected finding on another type of imaging or to help discover the cause of symptoms a patient may be experiencing. If a patient is scheduled for surgery or a biopsy, a CT scan allows localization of critical anatomic structures such as blood vessels, which may facilitate planning of the procedure. A physician will usually order a CT scan for the section of the body that is of interest, such as the head, neck, sinuses, spine, chest, abdomen or pelvis. The level of detail provided by a CT scan aids in the diagnosis and treatment planning for many medical conditions. Repeat CT scans may be ordered to identify changes in the area of interest.
How is the CT scan conducted?
If a scan is ordered “with contrast”, the patient will be asked to drink a special liquid 1-1.5 hours prior to the scan. In addition, a dye may be injected into the patient’s bloodstream. This helps the physician to get a better look at the structures in the body. Once the dye has been injected, a technician will walk the patient to the scanner and help him/her onto the table so that he/she is scanned in the proper position. It is important for the patient to stay as still as possible during the scan. Sometimes a patient may be asked to hold his/her breath briefly to make sure there is no movement while the pictures are taken. The scan can take 15-60 minutes depending on the area of the body that is being scanned.
Is a CT scan safe?
Yes. CT scans are associated with minimal radiation exposure; however, if a physician has ordered a CT scan, he/she feels that the benefits of the information provided by the scan outweigh any risk associated with this small level of exposure. It is important for a patient to tell the physician if he/she has ever had a reaction to contrast such as trouble breathing or a drop in blood pressure or if he/she is allergic to any medications such as iodine, prednisone or barium sulfate. In addition, a patient who is claustrophobic, diabetic or has asthma or an allergic disorder should notify his/her physician. Patients who are over the age of 50 may require a special lab test to make sure the kidneys are functioning properly prior to the scan.
How should I prepare for a CT scan?
- Arrive 15 minutes prior to the scheduled appointment.
- Wear comfortable clothing without zippers or other metal.
- Ingest NO FOOD OR DRINK for at least 4 hours prior to the scan (other than specified liquid contrast) unless specifically directed otherwise by the technician.
- Continue taking medications as usual. Direct all questions to the physicians who ordered the scan.
- Resume normal activities, including eating normal meals, following the scan.
- Drink fluids to help the dye exit the body faster upon completion of the CT.