RT Journal Article SR Electronic T1 The Collar Sign in Pipeline Embolization Device–Treated Aneurysms JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 486 OP 487 DO 10.3174/ajnr.A6465 VO 41 IS 3 A1 Moran, Christopher J. YR 2020 UL http://www.ajnr.org/content/41/3/486.abstract AB