The line of demarcation between the SN and the crus cerebri (Fig. 1) was determined by KB staining. We found that hyperintense areas in T1WI corresponded exactly to the extent of the SN, as delineated by histology. However, the ventral hypointense layers on the T2*WI were not coextensive with the SN, but instead extended partially into the posterior part of the crus cerebri and overlapped with the densely myelinated portions. In these areas, iron pigments stained using Perl’s technique were detected in the absence of TH-positive cells or NM (Fig. 2).