Computed Tomography, also knows as a CT or CT scan, is a medical procedure used to view geometry within the body that is not observable from the exterior. It uses X-ray technology to look through the body and is especially good at imaging high-density structures like bones. While traditional X-rays generate a single plane image, the CT uses an emitter and detector that rotates around the body collecting multiple images from different angles. Software within the device combines these individual scans into a slice through the body. During a single scan, the body is moved through the scanner so that multiple slices can be generated. These individual slices are stacked together to generate a 3D image of the body. Software enables the clinician to translate and rotate the 3D image like 3D CAD software used by engineers. The additional information provided by this technology has improved diagnosis of multiple medical conditions.
There are some concerns with using CT. Because it uses X-rays, it exposes the patient to ionizing radiation. Although each image exposes a person to only a small amount of radiation, the large total number of images required to generate a 3D image results in a higher level of radiation. The other issue is that CT is not able to view soft tissues as well as the other technology used to generate 3D body images, magnetic resonance imaging (MRI). However, this lack of sensitivity to soft tissues may be offset by the much faster scanning time for CT and the higher resolution. Like many competing technologies, the choice of imaging device depends on the application.
