The depth of the spinal cord below the skin.
D001415:Back / Q000000981:diagnostic imaging*; D006801:Humans; D009192:Myelography; D011879:Radiotherapy Dosage; D012867:Skin / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D013116:Spinal Cord / Q000033:anatomy & histology / Q000000981:diagnostic imaging*