Fig 4.

The distal reference (360° point) was defined in 2 ways according to Xu et al and Marsh et al, depending on where projected imaginary lines crossed the cochlear lumen [arrows in (A) and (B)]. For the Xu et al measurement (A), the imaginary line extended from the center of the cochlea to the midround window. For the Marsh et al measurement (B), the imaginary line extended from the center of the cochlea to a perpendicular vertical line through the superior semicircular canal and the vestibule.