Computed tomography (CT), also known as a CAT scan, allows us to make slice pictures of any part of the body. It is particularly useful for looking at the head, chest and abdomen.
CT uses an X-ray tube and X-ray detectors that rotate around a person as the person moves through the scanner in a very precise manner on a moving table. A computer then analyses the data and creates cross sectional images depicting the inside of the body. The images are generated in the axial plane (like slicing a loaf of bread into individual slices) but the data can be rearranged by the computer in the coronal plane (as if looking from the front) and in the sagittal plane (as if looking from the side) to better understand the internal anatomy.
CT is useful to understand a vast number of conditions including:
The original CT scanners were developed in England in the early 1970s at EMI (Electric and Musical Industries) and may have been partly funded by revenues from sales of Beatles records in the 1960s.
The first CT scanners were called EMI scanners, and could only scan the head. It took 4 minutes to scan the head with computer reconstruction of each slice requiring 7 minutes, so the scan could not be viewed for several hours.
Now scanners can scan through the entire head, chest, abdomen or pelvis in fewer than 15 seconds, with image reconstruction of the entire study available in less than a minute.