RT Journal Article SR Electronic T1 MR ‘scalpel sign’ of spinal arachnoid web JF Practical Neurology JO Pract Neurol FD BMJ Publishing Group Ltd SP 235 OP 236 DO 10.1136/practneurol-2021-003293 VO 22 IS 3 A1 Thomas Morrison A1 Raka Datta A1 Lynette Masters A1 Mike Boggild A1 Stephen Reddel A1 Jeffrey Brennan YR 2022 UL http://pn.bmj.com/content/22/3/235.abstract AB