Which factor does NOT affect absorption efficiency in CT imaging?

Absorption efficiency in CT imaging primarily depends on factors that directly influence how well X-rays are absorbed by the material being imaged and the detector technology used. The detector type plays a significant role, as various detectors have different efficiencies and response characteristics to X-ray photons. Material properties of the detector also affect how effectively it can convert incoming X-rays into measurable signals. Proton count might refer to certain aspects of imaging in other contexts, such as magnetic resonance imaging rather than in the context of X-ray absorption.

In this framework, patient age does not significantly influence absorption efficiency. While age can affect factors such as body composition and density, it does not directly impact the physical mechanisms of X-ray interaction with tissues or how detectors respond to X-ray photons. Therefore, considering these elements, patient age stands out as a factor that does not alter the fundamental processes that determine the efficiency of X-ray absorption in CT imaging.