Preschooler with short stature AP radiograph of the lumbar spine (left) shows progressive narrowing of the distance between the pedicles descending through the lumbar spine (interpediculate narrowing). The lateral radiograph of the lumbar spine (right) shows shortened pedicles leading to narrowing of the anterior-posterior diameter of the spinal canal (spinal stenosis) and that the vertebral bodies have some anterior wedging and posterior scalloping. The diagnosis was achondroplasia.