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Computerised axial tomography

In the case of X-rays the basic ideas of computerised axial tomography (CT) are developed. Following a description of the basic physics involved in X-ray picture formation the author explains the principles of CT by considering a simple scanning process and an iterative method of data analysis. This leads to an explanation of the presently most used method of analysis in CT machines: the modified back-projection or convolution method. Pictures produced by CT of the brain and body cross section are given to illustrate the high sensitivity of the technique.