CT scans and MRIs are medical imaging tools that allow doctors to view internal parts of the body, explains MedlinePlus. An MRI uses a large magnet and radio waves to provide a view of structures and organs, and a CT scan uses X-rays to take pictures of cross-sections.
Although both machines look similar, a CT scanner uses X-rays to take numerous pictures of a body as it moves through an arc, says Dr. Sanjeev Athale for The Sentinel. A CT scan offers detailed information about the body because it perceives different levels of density and tissue in an organ. A long ride on an airplane exposes people to more radiation than a typical CT scan. These medical machines are fast and use low doses of radiation.
MRI scans produce images of organs, bone and soft tissue through the use of powerful magnetic fields and radio waves. An MRI often produces better pictures of differences in normal and abnormal tissue than a CT scan. The type of scan used by a doctor depends on the part of the body the doctor wants to look at and what he is looking for, says Dr. Athale. Bone and muscle disorders, blood clots, tumors and fractures show up better on a CT scan. Ligaments and tendons, as well as the spinal cord, are seen more effectively with an MRI.