What primarily determines image contrast in radiographic images?

Image contrast in radiographic images is primarily determined by the differences in tissue density and composition. When X-rays pass through the body, they are absorbed to varying extents depending on the characteristics of the tissues they encounter. Dense structures, such as bones, absorb more X-rays and appear lighter on the radiograph, while less dense tissues, like muscles and organs, allow more X-rays to pass through, resulting in darker areas on the image. This differential absorption creates the contrast that allows for the differentiation of anatomical structures in the final image.

Factors like the exposure time, technician's skill, and type of X-ray equipment can influence the overall quality of an image, but they do not fundamentally alter the inherent contrast that arises from the varied densities and compositions of the tissues being imaged. Hence, understanding tissue density is crucial for interpreting radiographic images effectively, making it the primary determinant of image contrast.