Microscopic R2* mapping of reduced brain iron in the Belgrade rat.

R2* mapping has recently been used to detect iron overload in patients with movement disorders. We demonstrate here that this technique can also be used to detect reduced brain iron, as in the case of a missense mutation in the iron-transporting protein divalent metal transporter 1. Surprisingly, we found that the same brain regions are affected (ie, the globus pallidus, substantia nigra, and cerebellar dentate nucleus); this suggests a much more extensive role for these structures in regulating overall brain iron homeostasis. Therefore, for the clinical monitoring of movement disorders for which normal brain iron homeostasis (either overload or reduction) may be implicated, R2* mapping appears to be well-suited.