MRI visualization of iron accumulation in dentate nuclei of 3 young patients with Friedreich ataxia and 3 healthy age-matched subjects. The figure shows a parametric image of R2* values in posterior fossa, derived from the multigradient echo sequence done at 1.5 T. Dentate nuclei with high R2* values appear whiter than surrounding cerebellum, smaller, and irregularly shaped in FA patients compared with control subjects. R2* values of the adjacent cerebellum have values in the order of 14 s⁻¹, confirming good regional homogeneity of the magnetic field. The R2* values are given in the text. The above images are displayed following equal windowing and leveling of the R2* maps.