HOW CT SCANS WORK: Computerized Tomography (CT) scans use X-rays to image the body. X-rays can pass through most materials. It all depends on the size of the atoms that make up the material; larger atoms absorb X-ray photons, while smaller atoms do not, and the X-rays pass right through. For instance, the soft tissue in the body is composed of smaller atoms, so it doesn't absorb X-rays very well. But calcium atoms in the bones are much larger and do absorb X-rays. A camera on the other side of the patient records the patterns of X-ray light passing through the patient's body. In a CT scan, a series of X-ray beams is directed through the body from different angles. This creates cross-sections so scientists can get a better view of the body. The images are put together by computer into a stack of pictures that can be viewed rapidly, like flipping through a deck of cards.
The Acoustical Society of America, the American Mathematical Society, the Mathematical Association of America,ýý the American Statistical Association, the Society for Industrial and Applied Mathematics, the Biophysical Society and the Optical Society of America contributed to the information contained in the TV portion of this report.