Fig. 3.

Range of image cropping. Horizontally, the image was cut parallel at the most ventral part of the lumbar vertebral body. It was then cut in the dorsal direction from the center of thecal sac to the ventral end of the vertebral body (left side). Finally, it was cut vertically by the same length at the center of thecal sac (right side). The range within which both lateral sides of the vertebral body could be seen in all images was measured. This range was then applied to all images.