**9. MRI scanning: Risks and contraindications**

Up to 2.5 Tesla, the magnetic field does not trigger any biological or genetic risk.

The risks and contraindications for MRI are very rare, but they should be known to avoid an accident or scheduling of an unnecessary exam.

Risk factors are associated to a magnetic field that can produce heat, suffocation in case of discharge of a supra-conductor magnet with brutal gasification of the fluids that cools the magnet, patients' local burns caused exceptionally by the twisting of the antenna surface wire or its deterioration by the "coil" effect [21,32,33].

The exam is contraindicated for patients with cardiac pacemakers that can be affected tempo‐ rarily or permanently with risk of heart failure or rhythm disturbances; these risks exist regardless of the intensity of the magnetic field, metal and ferromagnetic bodies, and pregnant women [32,33].
