Ultrasonic measurement of the lumbar spinal canal. The origin and precision of the recorded echoes.
D004824:Epidural Space; D006801:Humans; D007403:Intervertebral Disc; D012826:Silicone Elastomers; D013115:Spinal Canal / Q000033:anatomy & histology*; D014463:Ultrasonography
D012826:Silicone Elastomers