Inflow Angle Impacts Morphology, Hemodynamics, and Inflammation of Side‐wall Intracranial Aneurysms

Abstract

Background: Aneurysm inflow angle has been shown to be associated with hemodynamic changes by computational fluid dynamics. However, these studies were based on single aneurysm model and were limited to side-wall aneurysms. Purpose: To investigate the association between inflow angle and morphology, hemodynamic, and inflammation of intracranial side-wall and bifurcation aneurysms. Study type: Prospective. Population: A total of 62 patients (aged 58.34 AE 12.39, 44 female) with 59 unruptured side-wall aneurysms and 17 unruptured bifurcation aneurysms were included. Field strength/sequence: A 3.0 T; 3D fast field echo sequence (TOF-MRA); free-breathing, 3D radio-frequency-spoiled, multi-shot turbo field echo sequence (4D-flow MRI); 3D black-blood T1-weighted volumetric turbo spin echo acquisition sequence (T 1 -VISTA) Assessment: Two neuroradiologists assessed the inflow angle and size for intracranial aneurysms in 3D space with TOF-MRA images. The average and maximum inflow velocity (V avg-IA , V max-IA ), blood flow (Flow avg-IA , Flow max-IA ), and average wall shear stress (WSS avg-IA ) for aneurysms were assessed from 4D-flow MRI in regions of interest drawn by two neuroradiologists. The aneurysmal wall enhancement (AWE) grades between precontrast and postcontrast T 1 -VISTA images were evaluated by three neuroradiologists. Statistical tests: Kruskal-Wallis H test, χ 2 test, Pearson's correlation coefficient, scatter plots and regression lines, multivariate logistic regression analysis (partial correlation r) were performed. A P < 0.05 was considered statistically significant.Results: The WSS avg-IA (0.52 AE 0.34 vs. 0.27 AE 0.22) and AWE grades (1.38 AE 1.04 vs. 2.02 AE 0.68) between the two inflow angle subgroups of side-wall aneurysms were significantly different. The aneurysm size (r s = 0.31), WSS avg-IA (r s = À0.45), and AWE grades (r s = 0.45) were significantly correlated with inflow angle in side-wall aneurysms. While in bifurcation aneurysms, there were no significant associations between inflow angle and size (P = 0.901), V avg-IA (P = 0.699), V max-IA (P = 0.482), Flow avg-IA (P = 0.550), Flow max-IA (P = 0.689), WSS avg-IA (P = 0.573), and AWE grades (P = 0.872). Data conclusion: A larger aneurysm size, a lower WSS and a higher AWE grade were correlated with a larger inflow angle in side-wall aneurysms.

Comparison of Ophthalmic Artery Morphological Characteristics and Retinal Vessel Diameter for Identifying Ocular Ischemic Syndrome

“…In addition, the angle between arteries or arterial segments might affect the hemodynamics. 39 , 40 Therefore, we evaluated the angle between the OA and the ipsilateral ICA. However, no significant difference was found between two groups.…”

Identifying pyroptosis- and inflammation-related genes in intracranial aneurysms based on bioinformatics analysis

“…The change of hemodynamic changes are the initial factors for the formation of IA, which may promote the chemotaxis of inflammatory cells and cause local vascular inflammatory response. [ 6 , 25 ]. Further, the transformation of smooth muscle cells from the contractile phenotype to the proinflammatory/promatrix remodeling type in IA tissues can be considered as response of vascular inflammation [ 26 ].…”

Editorial for “Inflow Angle Impacts Morphology, Hemodynamics, and Inflammation of Side‐Wall Intracranial Aneurysms”

“…In this issue of JMRI, Mingzhu Fu and colleagues applied 4D flow MRI to investigate in‐vivo hemodynamic differences between side‐wall and bifurcation IAs ≥4 mm in a prospective cohort of 62 patients 10 . They found that the IA inflow angle was associated with reduced average WSS, larger IA size, and evidence of aneurysm wall inflammation when controlling for IA location.…”