Is magnetic resonance imaging of human brain is harmful?

In human brains, there are a lot of macroscopic (∼100 nm) magnetite granules. Exposure of the patient's head in high strength magnetic fields could lead to penetrance of those particles into brain neurons and their staying there for a long period. That conclusion is the consequence of calculations based on the equations describing the dynamics of those particles under the action of ponderomotive magnetic, elastic and viscous forces. The role of iron in brain metabolism is not conclusively clear but there is evidence of the connection between excess iron and neurodegenerative diseases. In this regard, we consider it necessary to look more carefully at the matter of safety for brain magnetic resonance imaging.