Fan-Beam CT Systems

The x-ray source and the detector array are arguably the most critical components that determine the performance of a closed-bore CT system. This chapter reviews the historical trend and recent progress in these subsystems. This perspective can be used to predict further progress that might be made in the near future. While the basic principles of x-ray generation have not changed, there has been considerable progress in x-ray sources for CT, including the ability to withstand high forces and high power, modulate the illuminating flux, enable lower kV imaging, and maintain small focal spots at high mA. X-ray detector arrays can have a very large number of elements, allowing the development of wider cone beams. They also have lower electronic noise. The new generation of detectors will have smaller apertures and spectral resolution at the detector.