Which one is safer, CT or MRI?
In general, both CT and MRI scans are relatively safe. However, there can be problems. MRI scans should not be done on patients that have aneurysm clips (clips of the vessels within the brain) unless these clips are known to be MRI safe, as these clips can be pulled off and the patient could die from bleeding into the brain.
Another problem with the MRI is the presence of some cardiac pacemakers or defibrillators because the magnets can cause malfunctions in these battery-operated devices. Any metal devices that can interact with a magnetic field, for example, the presence of metal shavings in an organ, the eye, or extremity may be pulled out by the magnetic field. Moreover, other canisters that are metal (like some oxygen tanks) need to be kept away from MRI machines because they can be attracted to the magnet and injure or kill the patient.
CT scans do not have these problems; however, they do expose the patient to radiation, though it’s a relatively low dose. Certain types of CT scan may not be appropriate during pregnancy.