Lumbar Spine X-ray This webpage presents the anatomical structures found on lumbar spine radiographs. Spine X-ray, AP projection 1, Rib. 2, Transverse process. 3, Pedicle. 4, Spinous process. 5, Sacrum. 6, Sacroiliac joint. Lumbar spine X-ray, lateral view 1, Sacrum. 2, Spinous process. 3, Vertebral body. 4, Intervertebral disc space. 5, Intervertebral foramen. 6, Pedicle. 7, Inferior articular process. 8, Superior articular process. 9, Rib.