Iron imaging in neuroinflammation

Iron plays an important role in neuroinflammatory processes as part of the oxidative stress cascade and microglia activation. Magnetic resonance imaging (MRI) allows for one to assess iron noninvasively and has shown strong correlations between brain iron and MRI signal changes. This chapter discusses current MRI-based techniques for imaging brain iron in vivo. Specifically, techniques based on the magnitude (R2 and R2*) and phase (including quantitative susceptibility mapping) of the transverse relaxation signal are reviewed. Although phase-based techniques are gaining significant momentum in the field, both magnitude and phase have application-specific advantages, and provide complimentary information that can help to disentangle relevant signal changes due to iron from other signal sources.