Imaging Tests are a variety of diagnostic tests that create images of different aspects of the body, including organs and tissue. An imaging test is a way to see what is going on inside your body. These tests send forms of energy (x-rays, sound waves, radioactive particles, or magnetic fields) through your body. The changes in energy patterns made by body tissues create an image or picture. Pictures show normal body structures, functions and abnormal ones caused by accidents and diseases like cancer.