The MRI is a painless exam even though the machine is noisy. The MRI machine is a tube with a diameter of about 23,6″. People suffering from claustrophobia do not usually feel comfortable with this exam. Otherwise, the exam is not particularly uncomfortable; the subject just has to lie still during a certain time. Some people may also feel some effects while in the MRI area (metallic taste in the mouth, sensation of warmth, light vertigos), but they are only transitory effects (they fade out as soon as the subject is no longer in the magnetic field).

Magnetic field and RF waves used for the MRI image acquisitions are considered too low to cause any biological damage, unlike what could happen with radiofrequency emissions. The CHRU imagers all have the CE label which certifies the respect of European security standards.

Any MRI exam is contraindicated for subjects with pacemakers, and with ferromagnetic devices. Hence the precautions and the necessity to know the subject’s surgical history). Before starting the exam, the subject will be asked a few questions and prepared (removal of ferromagnetic devices, credit cards, watch, etc.), and then taken to the MRI room.


For some MRI exams, a contrast agent needs to be injected. It is generally well tolerated but can sometimes generate some minor allergic reactions (hives). More serious adverse reactions are extremely rare, and can usually be anticipated during the pre-exam consultation. During the course of the investigations at the CIC-IT no contrast agent is injected to healthy volunteers.