MRI imaging or scanning does not use X-ray but instead very, very high strength magnetic fields that allow the hydrogen in the body to be mapped thus creating images of the body similar to those of CT but without X-rays. 

Unfortunately MRI can not image everything as well as CT, so both techniques are useful in diagnosis.   MRI is particularly good at imaging muscle and soft tissues, especially the soft tissues of the brain and spinal cord but also things like the shoulder and knee joint.

The device used to obtain MRI images is similar to the CT scanner, but the space for the patient is more confining and scanner makes a peculiar "clicking" noise that some people find annoying.

MRI scans can be obtained at: