ABSTRACT
In a computed tomography (CT) scanner, an X-ray source and a detector (normally consisting of many pixel elements) are rotating around a patient. The X-ray beam is absorbed to some extent by bones and soft tissue, forming an intensity prole that is captured by the detector. This intensity prole is normally called a projection. As the system rotates, many synchronized projections are taken. Using a backprojection method, the image may be computed for diagnostics [1, 2]. CT detectors differ from other X-ray applications [1, 3] because of their much higher signal resolution and dynamic range (>16 bits). These requirements call for more-sophisticated data-acquisition systems, where noise and dynamic range pose severe difculties on design issues, as outlined in this chapter.
