CAT scans are a diagnostic tool. They’re often used by doctors in hospitals.
It is a form of an X-ray, but it is computed tomography which means it is multiple series of X-rays, performed with the assistance of a computer. They will take slices of body parts in a series , the doctors examine these to see if there are any deformities or damage to the hard tissues, such as fractures, or soft tissue damage.
CAT scans or CT scans are better for picking up defects in hard structures, they are more sensitive than a plain-film X-ray, but not as sensitive for picking up soft tissue damage as an MRI would be. You are exposed to a bit more radiation than you would with a traditional X-ray, but they are much more detailed and can provide a clinician with a clearer picture.