CT Scan is a radiologic technique, which combines the use of X-rays with computer technology to produce clear two or three dimensional cross-sectioned image of deep internal structures. It is also called CAT scan. It is advantageous over the simple x-ray studies as it provides more detailed information than X-rays and tends to minimse the amount of radiation exposure.
It was invented by an English Scientist, Godfey Hounsefield, for which he was awarded the Nobel Prize in 1978.Mechanism
A low-dose x-ray source moves in an arc (360o) around a specific part of the body being scanned and repeatedly sends out x-ray beams. As the beams pass through the body, the tissues absorb small amounts of radiation. Once the beam passes through, they are converted by light sensitive crystal detectors to electronic signals that are transmitted to the scanners computer. This is repeated until the same body section has been examined from all angles. A computer analyses the data and reconstructs the images of the internal organs in this section of the body. Many slices are stacked and a three dimensional view of the organ emerges on the video screen. The projected image, called a CT scan, comes on the television screen. CT scan provides a very accurate cross-sectional picture of any area of body and helps to pinpoint even small defects.
Significance
1) Entire scanning takes only seconds.
2) It is a painless procedure.3) X-ray dose equal to or less than many other procedures.
4) Much more detailed informations than radiography.5) Three dimensional view of the organ emerges.
6) Even small defects can be pin pointed.