Which interaction with matter contributes no useful information to the radiographic image?

Compton scattering is the interaction that does not contribute useful information to the radiographic image. In this process, an incident photon interacts with an outer-shell electron, resulting in the ejection of the electron from its atom and the scattering of the photon at a lower energy. While this scattering can occur in different directions, it generally reduces the contrast of the image by contributing to the background noise rather than providing useful diagnostic information.

In radiographic imaging, the goal is to obtain clear and detailed images that reveal the internal structures of the body. Compton scattering contributes to scatter radiation, which can degrade image quality and reduce contrast. This scattered radiation adds to the overall exposure but does not help in distinguishing between different tissue types or identifying structures, ultimately making it less useful for diagnostic purposes.

The other interactions mentioned, such as the photoelectric effect, contribute significantly to image formation by providing contrast due to differential absorption based on the atomic number of the tissues. Thermal noise primarily refers to random fluctuations that can affect electronic detectors in imaging systems but is not a fundamental interaction with matter in the context of image formation. Radiolysis of water involves chemical changes in tissues rather than contributing information to the image itself.