What term describes the amount of photons that are absorbed by the detector?

The term that describes the amount of photons absorbed by the detector is capture efficiency. Capture efficiency refers specifically to the effectiveness of the detector in converting incoming radiation (photons) into a measurable signal. A higher capture efficiency indicates that a greater proportion of the incident photons are being absorbed and utilized in the imaging process, which ultimately affects the overall image quality and the diagnostic efficacy of the radiographic system.

Detection efficiency, while related, encompasses the overall capability of the detector to provide a response to the radiation, including sensitivity to different photon energies, rather than strictly measuring how many photons are being absorbed. The fill factor, on the other hand, refers to the ratio of the sensitive area of the detector to the total area, and image quality index measures aspects of image clarity rather than absorption rates. Hence, capture efficiency provides the most direct insight into the absorption of photons by the detector itself.