Introduction Understanding the relationship between aneurysm wall enhancement (AWE), wall shear stress (WSS), and wall tension (WT) across different brain aneurysm compartments may improve the assessment of rupture risk and vessel wall dynamics. Our comprehensive analysis aimed to evaluate these characteristics across different brain aneurysm compartments. Methods Patients with intracranial aneurysms underwent 3-T high-resolution magnetic resonance imaging (MRI). T1-weighted images were obtained before and after administering gadolinium (Gd) contrast. 3D segmentations of the aneurysms were generated using 3D Slicer. AWE was quantified based on the signal intensity of the aneurysm wall on T1+Gd images. Finite element analysis calculated WT, while computational fluid dynamics assessed WSS metrics, including time-averaged wall shear stress (TAWSS), wall shear stress gradient (WSSG), and oscillatory shear index (OSI). AWE, WT, and WSS metrics were compared among aneurysms compartments and aneurysms stratified by size, aspect ratio (AR), and size ratio (SR). Results AWE was elevated in aneurysms with greater size and AR. WT and OSI were higher in aneurysms with larger sizes and higher AR and SR. Aneurysm necks exhibited higher WT, TAWSS, and WSSG compared to the aneurysm body. Irregular aneurysms displayed lower TAWSS, WSSG, and higher OSI in areas of high AWE. The bleb had the highest AWE and lowest WT and WSSG, while necks showed the lowest AWE and highest WT and WSSG. Conclusion Aneurysm necks typically exhibit high WT and WSS, while the body often shows low WSS. Blebs express elevated AWE alongside diminished WSS and WT which potentially increases rupture risk Key Points <Emphasis Type="BoldItalic">Question</Emphasis> Areas of high wall enhancement in irregular aneurysms are characterized by low wall sheer stress and high oscillatory sheer index. <Emphasis Type="BoldItalic">Findings</Emphasis> High risk structures such as daughter sacs exhibit the highest wall enhancement and lowest wall sheer stress. <Emphasis Type="BoldItalic">Clinical relevance</Emphasis> Comprehensive morphomechanical and wall enhancement analysis of brain aneurysms have the potential to offer valuable new insights into aneurysm biology.

Comprehensive morphomechanical and wall enhancement analysis of intracranial aneurysms

期刊论文
发表日期：

2025年2月13日

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Sebastian Sanchez,
Jacob M. Miller,
Adam Galloy,
Marco Nino,
Diego Ojeda,
Elena Sagues,
Carlos Dier,
Andres Gudino,
Rodrigo Jaramillo,
Edgar A. Samaniego

摘要

Introduction

Understanding the relationship between aneurysm wall enhancement (AWE), wall shear stress (WSS), and wall tension (WT) across different brain aneurysm compartments may improve the assessment of rupture risk and vessel wall dynamics. Our comprehensive analysis aimed to evaluate these characteristics across different brain aneurysm compartments.

Methods

Patients with intracranial aneurysms underwent 3-T high-resolution magnetic resonance imaging (MRI). T1-weighted images were obtained before and after administering gadolinium (Gd) contrast. 3D segmentations of the aneurysms were generated using 3D Slicer. AWE was quantified based on the signal intensity of the aneurysm wall on T1+Gd images. Finite element analysis calculated WT, while computational fluid dynamics assessed WSS metrics, including time-averaged wall shear stress (TAWSS), wall shear stress gradient (WSSG), and oscillatory shear index (OSI). AWE, WT, and WSS metrics were compared among aneurysms compartments and aneurysms stratified by size, aspect ratio (AR), and size ratio (SR).

Results

AWE was elevated in aneurysms with greater size and AR. WT and OSI were higher in aneurysms with larger sizes and higher AR and SR. Aneurysm necks exhibited higher WT, TAWSS, and WSSG compared to the aneurysm body. Irregular aneurysms displayed lower TAWSS, WSSG, and higher OSI in areas of high AWE. The bleb had the highest AWE and lowest WT and WSSG, while necks showed the lowest AWE and highest WT and WSSG.

Conclusion

Aneurysm necks typically exhibit high WT and WSS, while the body often shows low WSS. Blebs express elevated AWE alongside diminished WSS and WT which potentially increases rupture risk

Key Points

Question Areas of high wall enhancement in irregular aneurysms are characterized by low wall sheer stress and high oscillatory sheer index.

Findings High risk structures such as daughter sacs exhibit the highest wall enhancement and lowest wall sheer stress.

Clinical relevance Comprehensive morphomechanical and wall enhancement analysis of brain aneurysms have the potential to offer valuable new insights into aneurysm biology.