title: Unenhanced Time-of-Flight MR Angiography versus Gadolinium-Enhanced Time-of-Flight MR Angiography in the Follow-Up of Coil-Embolized Aneurysms.
abstract: Background and Purpose Coil embolization of ruptured and unruptured aneurysms has emerged as a widely accepted alternative to clipping. Unfortunately, coil-embolized aneurysms need a long-term imaging follow-up to confirm the stability of the occlusion status. We investigated whether contrast-enhanced time-of-flight (ToF) magnetic resonance angiography (MRA) (gadolinium [Gd]-ToF) provides any diagnostic benefit over conventional ToF MRA (nonenhanced [NE]-ToF) in this context. Material and Methods From October 2013 to January 2015, all patients who were regularly scheduled for their follow-up after coil embolization were examined with Gd-ToF and NE-ToF angiography. The general visibility of the occlusion result was compared between the two MRAs as well as with the last digital subtraction angiography (DSA) available. Subgroups of interest (follow-up after stent-assisted coil embolization, cases with already known aneurysm remnants) were also analyzed. Results A total of 70 patients (44 female) harboring 74 treated aneurysms were examined. The reproducibility of the DSA result in terms of therapeutic relevance was 100%. In 10 of 74 cases (14%), the aneurysm status was more difficult to judge in the NE-ToF images (p = 0.02), and the visualization of small vessels was significantly better in the Gd-ToF (p = 0.003). NE-ToF did not fail to show any aneurysm remnants but were more difficult to depict in 35% of the cases (p = 0.09). Regarding the aneurysms that were coiled with stent assistance, there was no significant difference in terms of the visualization (p = 0.1). Conclusion Gd-ToF angiography is in general not superior to NE- ToF for the follow-up of coil-embolized aneurysms.
authors.affiliation: Department of Neuroradiology, Georg-August-University Göttingen, University Medical Center, Göttingen, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Behme
authors.affiliation: Department of Neurosurgery, Georg-August-University Göttingen, University Medical Center, Göttingen, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Malinova
authors.affiliation: Department of Neuroradiology, Georg-August-University Göttingen, University Medical Center, Göttingen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Kallenberg
authors.affiliation: Department of Neuroradiology, Georg-August-University Göttingen, University Medical Center, Göttingen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Knauth
authors.affiliation: Department of Neuroradiology, Georg-August-University Göttingen, University Medical Center, Göttingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Mohr
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction / Q000379:methods*; D002533:Cerebral Angiography / Q000379:methods*; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000628:therapy; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D005682:Gadolinium