Which type of radiation is primarily responsible for the imaging process in radiology?

X-rays are the primary type of radiation used in the imaging process in radiology due to their unique properties that allow for the visualization of internal structures within the body. They have a high enough energy level to penetrate various tissues, making it possible to create images of bones and soft tissues. When X-rays pass through the body, they are absorbed in different amounts by different tissues; for example, bones absorb more X-rays than soft tissues, which results in the contrast necessary to produce clear diagnostic images.

In comparison, ultrasound uses high-frequency sound waves to create images and is primarily useful for soft tissue imaging rather than X-ray-based structures. Infrared radiation is typically not used in medical imaging as it doesn't have the penetration ability needed for viewing internal body structures. Gamma rays, while also a form of high-energy radiation, are used in specific nuclear medicine applications rather than standard radiology imaging. Thus, the other forms of radiation do not fulfill the requirements necessary for the conventional imaging processes in radiology to the same degree that X-rays do.