CT scanning, or computed tomography scanning, is a type of computed tomography imaging that usually does not require contrast. Computed tomography, on the other hand, usually requires contrast to be injected and then enhanced to show a three-dimensional image of the target organ. Computed tomography scanning usually requires the patient to lie flat in the scanning machine for scanning, and usually only a single scan is performed, after which a two-dimensional flat image is obtained. Computed tomography, on the other hand, involves injecting a contrast medium into the patient’s blood vessels on top of the scan to better visualize the location and shape of the lesion. Therefore, if a patient needs to undergo computed tomography, it is important to do so under the guidance of a physician and follow the doctor’s instructions for choosing the appropriate test.