Fig. 4From: Reducing surgical levels by paraspinal mapping and diffusion tensor imaging techniques in lumbar spinal stenosisZone definition of the spinal nerve root at the lumbar spinal canal. The area between the inner edge of both pedicles was defined as the intraspinal zone (a), the width of pedicle was defined as the intraforaminal zone (b), and the area outer to the outer edge of pedicle was defined as the extraforaminal zone (c) [25]Back to article page