Moreover, with our knowledge of deferiprone's ability to scavenge cell iron,2,29,48 and assuming the concentration of chelator attained in the brain to be similar to that in plasma (at most 20-30 ??M at peak values after a single 10 mg/kg/d dose of chelator and a t?? value of 2-3 hours in plasma),26 one can deduce that the R2* in the dentate nuclei represents (a) accumulated forms of iron that are