Radiographers are medical experts who operate extremely sophisticated, cutting-edge scanning devices. These medical imaging technicians run medical imaging equipment, whereas radiologists are primarily concerned with imaging interpretation. Although both provide essential services to patients as part of a healthcare team, only radiologists can actually read images for signs of disease or injury. Radiology is the branch of medicine that deals with diagnostic imaging procedures such as X-rays, CAT scans, MRIs, and ultrasounds. Only doctors who have completed additional training in radiology can technically be called radiologists. However, many physicians perform some type of image analysis during their daily rounds, which means they can play an important role in the diagnosis of diseases without being labeled as a radiologist. Image analysis involves the study of visible features on X-rays, CT scans, and other medical images. Physicians interpret these images in order to make a diagnosis. Some examples of diagnoses made using image analysis include: detection of breast cancer tumors by looking at mammograms; identification of blood clots in legs by looking at leg X-rays; and visualization of the lungs' interior after inhalation of a radioactive substance (for example, during a pulmonary angiogram).