As with any medical imaging test, MRI tests involve the use of strong magnetic fields, and patients with certain medical devices, such as pacemakers or joint implants, may not be able to undergo the test. It is important to inform the radiologist or technologist if you have any medical devices or conditions that may be affected by the MRI. Additionally, the test may not be suitable for patients who experience claustrophobia or anxiety in enclosed spaces, as the MRI machine is a narrow tube-shaped device that can be noisy during the procedure.