Computed tomography (CT) reconstruction is a medical imaging technique where a series of “slices,” or individual images of the inside of the body, are stacked and correlated with each other to create a meaningful diagnostic image. This is usually done by a computer with the assistance of some mathematical formulas. The computer can take the input from the CT machine, run it through the formula, and return a set of images for a physician to examine. This can be done very rapidly, which may be useful in an emergency situation where a doctor needs immediate feedback.
Historically, medical imaging with x-rays involved x-raying the part of interest and then visually filtering through the noise in the image to find the necessary information. With computed tomography, a series of slices are taken instead. The device images a specific plane of the body, and can take multiple slices to build up a complete image. An individual slice can provide some information, and as a collective whole, the slices provide a detailed picture of the inside of the body.
One way to use CT reconstruction is in a flat image that combines multiple slices from the scan for the most possible information. This will allow a doctor to identify abnormalities and determine their exact location on the basis of which slices contain them and which slices do not. When the image is done with contrast, the doctor can see even more detail in the CT reconstruction, as particular parts of the patient's body will be highlighted on the finished image.
In another form of CT reconstruction, it is possible to reassemble the flat sections into a three dimensional image, which can be extremely useful for diagnostic purposes. The doctor can rotate or cut into the image to visualize particular areas of interest. Viewing structures in a simulation of three dimensions may also help with planning for surgery and pinpointing the location of a structure.
Another use for CT reconstruction can come up in archeology and forensics. In archeology, researchers often want to examine human remains but do not want to disturb them by unwrapping them or cutting into them. They can use a CT reconstruction to image the entire set of remains and create a reconstruction of the body to examine. This can allow researchers to do things like determining cause of death without having to destroy the body. Sets of scans of this nature can also be useful in forensics to image a body before proceeding with an autopsy, in case the pathologist wants references to look at later.