In the context of CT imaging, which process involves low-energy photons being absorbed first?

The process referred to in this context is known as beam hardening. In computed tomography (CT) imaging, beam hardening occurs when low-energy photons are absorbed more readily than high-energy photons as the X-ray beam passes through dense materials, such as tissues or bones. As the lower energy photons are absorbed, the average energy of the remaining photons that continue to traverse the material becomes higher. This leads to a phenomenon known as beam hardening, where the resultant images may exhibit artifacts that can affect the accuracy of tissue density measurements and overall image quality.

Understanding beam hardening is essential for interpreting CT images correctly, as these artifacts may misrepresent the presence of structures or pathology within the scanned region. This aspect of CT imaging is critical for radiologists and technologists to comprehend, ensuring they account for such factors during image acquisition and analysis.