ABSTRACT
Radiation dose may be reduced by increasing the detector efficiency of the imaging system (see Chapter 2) and often involves more efficient methods to detect and convert x-rays into image signals. This type of improvement is fundamental but does not come easily. Notable examples include the development of
modern detectors used in CT and the flat panel detectors used for projection imaging as well as CBCT (see Chapter 1). Actually, the efficiency of modern flat panel detectors probably motivated and led to the development of many CBCT systems and techniques for clinical applications many years after the use of less efficient CBCT systems for industrial and small-animal imaging. A second strategy is to match the spatial resolution of the imaging system to the imaging tasks intended for. High-resolution capability often requires the use of higher exposures. Conversely, lower resolution, if acceptable for the imaging tasks intended for, allows lower exposures to be used, thus saving the radiation dose to the patient. Examples include the use of binning in CBCT for radiation treatment verification or other applications that do not require high spatial resolution (see Chapter 15).
