Speculating the timing of iron deposition in the putamen in multiple system atrophy.

•We speculated a timing of putaminal iron deposition in multiple system atrophy (MSA).•A timing of R2* increment was speculated using conditional probability (CP) modeling.•CPs for R2* increment were lower than those for volume or mean diffusivity changes.•Putaminal iron deposit may be a secondary byproduct of neurodegeneration in MSA.