A medical imaging method employing tomography created by computer processing. Digital geometry processing is used to generate a three-dimensional image of the inside of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation. CT produces a volume of data which can be manipulated, through a process known as "windowing", in order to demonstrate various bodily structures based on their ability to block the X-ray beam. Although historically the images generated were in the axial or transverse plane orthogonal to the long axis of the body, modern scanners allow this volume of data to be reformatted in various planes or even as volumetric (3D) representations of structures. Although most common in medicine, CT is also used in other fields, such as nondestructive materials testing.
Once in comfortable clothing and after taking a contrast medium, a technologist will position you on the examination table. The technologist will then secure your head with a strap, since even slight movements can blur the image. You will then be moved into the scanner and may hear a slight whirring sound which is normal and to be expected. The procedure may take from 10 minutes to an hour to perform.
No a CT Scan does not hurt.
You may be told to avoid food or fluids 4-8 hours before the test. If a contrast substance is used, the substance is often given by mouth or injection at some point in the CT Scan procedure. It highlights certain structures, making the results more readable. Where loose, comfortable clothing for the scan and bring something to do in case the schedule at the office is tight. If you taking medications or you have medical conditions such as Diabetes, kidney or heart failure, make sure CT staff aware of these. You should not get CT contrast if allergic to iodine, unless special precautions are taken.
When the scan in completed you may return to your normal lifestyle while you wait for the results.