Fig. 1From: Ultra high-field SWI of the substantia nigra at 7T: reliability and consistency of the swallow-tail sign a Oblique-axial 1 mm MPR depicting the SN in two healthy subjects. Different slices for demonstration purposes. b Nigrosome 1 and consequently the swallow-tail sign can be readily visualized (filled arrow). c Absent swallow-tail sign (arrow)Back to article page