How Does A CT Scanner Work?

X-Ray computed tomography (or CT) is a common method of getting a detailed look into the workings of the human body. CT scans are more detailed than single X-rays, due to the examiner's ability to analyze the image in three dimensions.

Image aquisition

The CT scanner works in much the same way as an X-ray machine. Beams of x-rays are aimed at the body and measured after passing through, which enables mapping of the densities of particular body parts. The only fundamental difference between regular X-rays and CT scanners is that CT scanners take multiple images along the same axis. The camera rotates around the body in order to produce a series of X-rays that the computer can then interpret. Sometimes, if the doctor needs to see certain parts of the body, they can inject a contrast dye that lights up under X-rays in order to better expose a particular organ.

Computer interpretation

Thanks to the recent advances in CT scanning, the reconstruction is no longer limited to axial views. Today's software can reassemble the entire body by putting together each respective slice to form a full, rotatable 3D image. This is similar to stacking flat squares of different dimensions to create a pyramid. The power of today's computers allows scanners to render high-definition 3D models on the fly. CT scans are a superior alternative to x-rays, especially for tissues and organs besides bones, because the CT scan is not limited to a single, flat image.

With today's CT scaning technology, doctors can more accurately find and identify tumors, blood clots and other conditions that demand quick diagnosis to ensure the patient's survival prompt treatment.

Doctors can more accurately find and identify tumors and blood clots

by Erica Aros, Medical writer