Morphological factors affecting vortex core instability on 4D flow MRI of unruptured cerebral aneurysms. (4th May 2022)

• Record Type: Journal Article
• Authors: Futami, Kazuya; Misaki, Kouichi; Uno, Takehiro; Nambu, Iku; Kamide, Tomoya; Nakada, Mitsutoshi
• Is Part Of: Neurological research. Volume 44:Number 5(2022)
• Page Start: 455
• Page End: 462
• Publication Date: 2022-05-04
• Subjects: Unruptured cerebral aneurysm -- vortex core -- intra-aneurysmal flow instability -- size ratio -- 4D flow MRI; Neurology -- Periodicals; Neurosciences -- Periodicals; 616.8005
• DOI: 10.1080/01616412.2021.2004365
• Languages: English
• ISSNs: 0161-6412

Abstract

ABSTRACT: Objective: The spatiotemporal instability of intra-aneurysmal vortex flow may be associated with unruptured cerebral aneurysm rupture. We identified morphological factors that affect intra-aneurysmal vortex core patterns classified based on the instability on four-dimensional (4D) flow magnetic resonance imaging (MRI) and determined cutoff values for the factors to discriminate unstable core patterns. Methods: We classified vortex core patterns of 40 unruptured aneurysms on 4D flow MRI into stable, stable with a flapping tip, continuously deforming wave-or-coil-like, and non-visualized. We statistically compared nine morphological parameters among aneurysm groups with individual patterns. Results: The vortex cores were stable ( n = 16) (group A), stable with a flapping tip ( n = 15) (group B), wave-or-coil-like ( n = 7) (group C), and non-visualized ( n = 2) (group D). Since there were no statistically significant differences between groups A and B, we compared the difference between the groups A and B and the other groups. Multivariate logistic regression analyses found that size ratio (SR) was an only independently significant parameter ( p < 0.05). The receiver-operating characteristic analysis between groups A and B and group C and between groups A and B and groups C and D revealed that the area under the curve value for SR was the highest (0.829 [95% CI, 0.642–1.0]; 0.867 [95% CI, 0.715–1.0], respectively) among morphological factors; the cutoff value for SR was 1.72 (specificity 0.714, sensitivity 0.756; specificity 0.806, sensitivity 0.778, respectively). Conclusion: SR was an independent morphological factor contributing to vortex core instability based on the vortex core patterns on 4D flow MRI. Abbreviations: CFD: computational fluid dynamics; 3D: three-dimensional; 4D: four-dimensional; MRI: magnetic resonance imaging; MRA: magnetic resonance angiography; ICA: internal carotid artery; AR: aspect ratio; SR: size ratio; CI: confidence interval; AUC: area under the curve; ROC: receiver-operating characteristic