title: Reviewer's comment.
authors.affiliation: University Hospital AZG, NL-9700 RB Groningen, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Penning
mesh_terms: D006801:Humans; D011859:Radiography; D013124:Spinal Injuries / Q000000981:diagnostic imaging*; D013131:Spine / Q000000981:diagnostic imaging*