Final answer:
A CT scanner saves a portion of the collected CT data that is not reconstructed for viewing. This raw data is used to produce a highly detailed three-dimensional X-ray image of the body.
Step-by-step explanation:
A CT scanner collects a large amount of CT data during a scan, but not all of it is reconstructed for viewing. The portion of the CT data that is saved by the scanner but not reconstructed is known as raw data. This raw data includes information about the relative absorption of X-rays in different directions.
The raw data is processed by complex computer-image algorithms to produce a highly detailed three-dimensional X-ray image of the body. The processing of the raw data involves reconstructing the image from multiple slices of the scanned area. The reconstructed image can then be viewed by medical professionals.