The Vision of the PCH District is to be the
Best Place to Get Care and the Best Place to Give Care.
CT Scan (Tomography)
What is a CT Scan?
A CT or CAT scan is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, organs, and blood vessels. CT scans are more detailed than standard X-rays.
In computed tomography, the X-ray beam moves in a circle around the body. This allows many different views of the same organ or structure, and provides much greater detail. The X-ray information is sent to a computer that interprets the X-ray data and displays it in two-dimensional form on a monitor. Newer technology and computer software makes three-dimensional (3-D) images possible.
CT scans may be done with or without contrast. "Contrast" refers to a substance taken by mouth or injected into an intravenous (IV) line that causes the particular organ or tissue under study to be seen more clearly. Contrast examinations may require you to fast for a certain period of time before the procedure. Your doctor will notify you of this prior to the procedure.
CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage.
You may want to ask your doctor about the amount of radiation used during the CT procedure and the risks related to your particular situation. It is a good idea to keep a record of your past history of radiation exposure, such as previous CT scans and other types of X-rays, so that you can inform your doctor. Risks associated with radiation exposure may be related to the cumulative number of X-ray examinations and/or treatments over a long period of time. If you are pregnant or suspect that you may be pregnant, you should notify your doctor.
How is a CT or CAT scan performed?
CT scans can be performed on an outpatient basis, unless they are part of a patient's inpatient care.
1. When the patient arrives for the CT scan, he or she will be asked to remove any clothing, jewelry, or other objects that may interfere with the scan.
2. If the patient will be having a procedure done with contrast, an intravenous (IV) line will be started in the hand or arm for injection of the contrast medication. For oral contrast, the patient will be given the contrast material to swallow.
3. The patient will lie on a scan table that slides into a large, circular opening of the scanning machine.
4. The Medical Imaging staff will be in another room where the scanner controls are located. However, the patient will be in constant sight of the staff through a window. Speakers inside the scanner will enable the staff to communicate with and hear the patient. The patient may have a call bell so that he or she can let the staff know if he or she has any problems during the procedure.
5. As the scanner rotates around the patient, X-rays will pass through the body for short amounts of time. The motion is hidden inside the gantry, the doughnut-shaped part of the machine. The patient may hear buzzing, whirring, and clicking as the X-ray tube rotates.
6. The X-rays absorbed by the body's tissues will be detected by the scanner and transmitted to the computer.
7. The computer will transform the information into an image to be interpreted by the radiologist.
8. It is very important that the patient remain very still during the procedure. You may be asked to hold your breath at various times during the procedure.
9. The technologist will be watching the patient at all times and will be in constant communication.
10. The patient may be asked to wait for a short period of time while the radiologist examines the scans to make sure they are clear. If the scans are not clear enough to obtain adequate information, the patient may need to have additional scans performed.