Allan M. Cormack was a physicist whose theoretical analysis and experiments in nuclear and particle physics, computer tomography, and math led to his invention of a mathematical technique for computer-assisted x-ray tomography, which revolutionized noninvasive medical diagnosis.

Computerized axial tomography, otherwise known as the CAT scan, is a process by which x rays can be concentrated on specific sections of the human body at a variety of angles. Once this information is analyzed by a computer, it is combined to reproduce images of internal structures previously unviewable by medical technology. It is considered the most revolutionary development in the field of radiography since the discovery of the x ray by Wilhelm Conrad Röntgen in 1895.

Cormack was the first to analyze the possibility of such an examination of a biological system in 1963 and 1964, and to develop the equations needed for computer-assisted x-ray reconstruction of pictures of the...