CT scans take a fast series of X-ray pictures, which are put together to create images of the area that was scanned. An MRI uses strong magnetic fields to take pictures of the inside of the body.

CT scans take a fast series of X-ray pictures, which are put together to create images of the area that was scanned. An MRI uses strong magnetic fields to take pictures of the inside of the body. CT scans are usually the first choice for imaging. MRIs are useful for certain diseases that a CT scan cannot detect.