Fig 4.

Axial CT and MR images of 1 of the 4 patients who was found, in retrospect, to have abnormal distance X measurements on MR imaging. A, On CT, the typical findings of IP-II including flattening of the interscalar ridge (anchor point) between the upper basal and upper middle turns (arrow) are demonstrated and confirm the presence of an IP-II anomaly. B, Corresponding MR image, on which distance X is found to be greater than 1.2 mm.