Since the first X-ray of Anna Bertha Ludwig’s hand in 1895, taken by her husband, Wilhelm Conrad Röntgen, the X-ray has been an invaluable tool in medicine, allowing us to look inside a patient. However, the standard X-ray provides only a two-dimensional view of the body. We would like to have a three-dimensional view, which is the goal of computed tomography. The word tomography comes from the Greek word tomos or slice. Tomography, then, is a method for creating a slice or cross-section of a three-dimensional object. The cross-sections can be assembled to get the three-dimensional representation. Computed tomography uses X-rays to provide the illumination and computational algorithms to combine the images generated by the X-rays into a three-dimensional image. The three-dimensional object, in our case, the human body, is irradiated by X-rays from multiple directions. Sensors around the body detect the degree of absorption of these X-rays. These absorption profiles are combined using a computational algorithm to construct a three-dimensional view of the body.