scholarly journals Effect of Aneurysm and Patient Characteristics on Intracranial Aneurysm Wall Thickness

2021 ◽  
Vol 8 ◽  
Author(s):  
Jason M. Acosta ◽  
Anne F. Cayron ◽  
Nicolas Dupuy ◽  
Graziano Pelli ◽  
Bernard Foglia ◽  
...  
Keyword(s):  
Intracranial Aneurysm ◽  
Wall Thickness ◽  
Positive Family History ◽  
Patient Characteristics ◽  
Western World ◽  
University Hospitals ◽  
Thickness Uniformity ◽  
Neck Size ◽  
Aneurysm Wall

Background: The circle of Willis is a network of arteries allowing blood supply to the brain. Bulging of these arteries leads to formation of intracranial aneurysm (IA). Subarachnoid hemorrhage (SAH) due to IA rupture is among the leading causes of disability in the western world. The formation and rupture of IAs is a complex pathological process not completely understood. In the present study, we have precisely measured aneurysmal wall thickness and its uniformity on histological sections and investigated for associations between IA wall thickness/uniformity and commonly admitted risk factors for IA rupture.Methods: Fifty-five aneurysm domes were obtained at the Geneva University Hospitals during microsurgery after clipping of the IA neck. Samples were embedded in paraffin, sectioned and stained with hematoxylin-eosin to measure IA wall thickness. The mean, minimum, and maximum wall thickness as well as thickness uniformity was measured for each IA. Clinical data related to IA characteristics (ruptured or unruptured, vascular location, maximum dome diameter, neck size, bottleneck factor, aspect and morphology), and patient characteristics [age, smoking, hypertension, sex, ethnicity, previous SAH, positive family history for IA/SAH, presence of multiple IAs and diagnosis of polycystic kidney disease (PKD)] were collected.Results: We found positive correlations between maximum dome diameter or neck size and IA wall thickness and thickness uniformity. PKD patients had thinner IA walls. No associations were found between smoking, hypertension, sex, IA multiplicity, rupture status or vascular location, and IA wall thickness. No correlation was found between patient age and IA wall thickness. The group of IAs with non-uniform wall thickness contained more ruptured IAs, women and patients harboring multiple IAs. Finally, PHASES and ELAPSS scores were positively correlated with higher IA wall heterogeneity.Conclusion: Among our patient and aneurysm characteristics of interest, maximum dome diameter, neck size and PKD were the three factors having the most significant impact on IA wall thickness and thickness uniformity. Moreover, wall thickness heterogeneity was more observed in ruptured IAs, in women and in patients with multiple IAs. Advanced medical imaging allowing in vivo measurement of IA wall thickness would certainly improve personalized management of the disease and patient care.

Quantitative analysis of unruptured intracranial aneurysm wall thickness and enhancement using 7T high resolution, black blood magnetic resonance imaging

2021 ◽  
pp. neurintsurg-2021-017688
Author(s):  
Xinke Liu ◽  
Junqiang Feng ◽  
Zhixin Li ◽  
Zihao Zhang ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Intracranial Aneurysm ◽  
Wall Thickness ◽  
Signal Intensity ◽  
Spin Echo ◽  
Fast Spin Echo ◽  
Black Blood ◽  
Post Contrast ◽  
Isotropic Resolution ◽  
Aneurysm Size ◽  
Aneurysm Wall

BackgroundThis study was performed to quantify intracranial aneurysm wall thickness (AWT) and enhancement using 7T MRI, and their relationship with aneurysm size and type.Methods27 patients with 29 intracranial aneurysms were included. Three-dimensional T1 weighted pre‐ and post-contrast fast spin echo with 0.4 mm isotropic resolution was used. AWT was defined as the full width at half maximum on profiles of signal intensity across the aneurysm wall on pre-contrast images. Enhancement ratio (ER) was defined as the signal intensity of the aneurysm wall over that of the brain parenchyma. The relationships between AWT, ER, and aneurysm size and type were investigated.Results7T MRI revealed large variations in AWT (range 0.11–1.24 mm). Large aneurysms (>7 mm) had thicker walls than small aneurysms (≤7 mm) (0.49±0.05 vs 0.41±0.05 mm, p<0.001). AWT was similar between saccular and fusiform aneurysms (p=0.546). Within each aneurysm, a thicker aneurysm wall was associated with increased enhancement in 28 of 29 aneurysms (average r=0.65, p<0.05). Thicker walls were observed in enhanced segments (ER >1) than in non-enhanced segments (0.53±0.09 vs 0.38±0.07 mm, p<0.001).ConclusionImproved image quality at 7T allowed quantification of intracranial AWT and enhancement. A thicker aneurysm wall was observed in larger aneurysms and was associated with stronger enhancement.

scholarly journals Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
S. Voß ◽  
S. Glaßer ◽  
T. Hoffmann ◽  
O. Beuing ◽  
S. Weigand ◽  
...  
Keyword(s):  
Intracranial Aneurysm ◽  
Wall Thickness ◽  
Ex Vivo ◽  
Thickness Distribution ◽  
Wall Stress ◽  
Patient Specific ◽  
Fluid Structure ◽  
Aneurysm Wall ◽  
Ruptured Intracranial Aneurysm ◽  
Rupture Site

Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness usingμCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI) simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches—when averaged over the complete aneurysm sac—are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations.

Aneurysm Wall Thickness Measurements of Experimental Aneurysms: In Vivo High-Field MR Imaging Versus Direct Microscopy

2014 ◽  
pp. 17-20
Author(s):  
Camillo Sherif ◽  
Günther Kleinpeter ◽  
Michel Loyoddin ◽  
Georg Mach ◽  
Roberto Plasenzotti ◽  
...  
Keyword(s):  
Mr Imaging ◽  
Wall Thickness ◽  
High Field ◽  
Direct Microscopy ◽  
Aneurysm Wall ◽  
High Field Mr ◽  
Thickness Measurements

scholarly journals Intracranial aneurysm wall enhancement as an indicator of instability – Systematic Review and Meta‐Analysis

2021 ◽  
Author(s):  
Rob Molenberg ◽  
Marlien W. Aalbers ◽  
Auke P.A. Appelman ◽  
Maarten Uyttenboogaart ◽  
J. Marc C. van Dijk
Keyword(s):  
Systematic Review ◽  
Intracranial Aneurysm ◽  
Meta Analysis ◽  
Aneurysm Wall

scholarly journals B-PO03-096 DIELECTRIC IMAGING ACCURATELY MEASURES REGIONAL CARDIAC CHAMBER WALL THICKNESS - AN IN VIVO STUDY

Heart Rhythm ◽  
2021 ◽  
Vol 18 (8) ◽  
pp. S227-S228
Author(s):  
Irum Kotadia ◽  
Iain Sim Michelle Williams ◽  
Caroline H. Roney ◽  
Jose Solis-Lemus ◽  
Orod Razeghi ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Chamber Wall ◽  
In Vivo Study ◽  
Cardiac Chamber

Abstract 147: Role of Nicotine in the Development of Intracranial Aneurysm Rupture

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Yoshinobu Kamio ◽  
Hajime Furukawa ◽  
Kimihiko Yokosuka ◽  
Masaaki Korai ◽  
Kazuha Mitsui ◽  
...  
Keyword(s):  
Intracranial Aneurysm ◽  
Tobacco Smoke ◽  
Intracranial Aneurysms ◽  
Aneurysm Rupture ◽  
Alpha7 Nicotinic Acetylcholine Receptor ◽  
Acetate Salt ◽  
Nicotine Receptors ◽  
Aneurysm Wall ◽  
Salt Hypertension

Background: Nicotine is one of main chemicals of tobacco smoke and promotes atherosclerosis and stroke. Tobacco smoke is considered an independent risk factor for intracranial aneurysm formation, growth, and rupture. There are mainly 5 subtypes of nicotine receptors. Roles of alpha7 nicotinic acetylcholine receptor (α7nAChR) in inflammation and vascular remodeling are diverse and context-dependent. Notably, endothelial α7nAChR is considered to mediate nicotine-induced inflammation. Activation of endothelial α7nAChR by nicotine may promote aneurysm rupture by increasing the aneurysm wall inflammation. Using a mouse model of intracranial aneurysm, we examined effects of nicotine in aneurysm rupture. Moreover we investigated potential roles of α7nAChR stimulation by nicotine in the pathophysiology of intracranial aneurysms. Methods: Intracranial aneurysms were induced by a combination of elastase injection into the cerebrospinal fluid and deoxycorticosteron acetate-salt (DOCA-salt) hypertension in male mice. Mice were treated with (1) nicotine (5 mg/kg/day, n=25); (2) saline sc (n=22) for three weeks after aneurysm induction. To investigate the effect of α7nAChR, mice were treated with (1) saline sc + saline ip (n=11); (2) saline sc + α7nAChR antagonist (Methyllycaconitine, MLA 5mg/kg/day) ip (n=13); (3) nicotine (5 mg/kg/day, sc, 28 days) + saline ip (n=18); (4) nicotine sc + MLA ip (n=18). Results: Nicotine alone significantly increased aneurysmal rupture compared with saline treatment (89% vs 46%, p=0.009). While α7nAChR antagonist did not affect the incidence of aneurysm or rupture rates, the α7nAChR antagonist significantly reduced the deleterious effect of nicotine as indicated by the reduction of the rupture rates (41% vs 100%: nicotine sc + MLA ip group vs nicotine sc + saline ip group, p=0.027). Conclusion: Our data indicate the promotion of aneurysm rupture by nicotine may be mediated by its stimulation of alpha7nAChR.

Quantitation of intracranial aneurysm neck size from diagnostic angiograms based on a biomathematical model

1995 ◽  
Vol 17 (5) ◽  
pp. 322-328 ◽  
Author(s):  
George J. Hádemenos ◽  
Tarik F. Massoud ◽  
Fernando Viñuela
Keyword(s):  
Intracranial Aneurysm ◽  
Neck Size ◽  
Aneurysm Neck

scholarly journals Infarcted Left Ventricles Have Stiffer Material Properties and Lower Stiffness Variation: Three-Dimensional Echo-Based Modeling to Quantify In Vivo Ventricle Material Properties

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Longling Fan ◽  
Jing Yao ◽  
Chun Yang ◽  
Dalin Tang ◽  
Di Xu
Keyword(s):  
Wall Thickness ◽  
Material Properties ◽  
Strain Curve ◽  
Stress And Strain ◽  
Stress Strain ◽  
Material Stiffness ◽  
The Mean ◽  
Lv Volume ◽  
Parameter Values

Methods to quantify ventricle material properties noninvasively using in vivo data are of great important in clinical applications. An ultrasound echo-based computational modeling approach was proposed to quantify left ventricle (LV) material properties, curvature, and stress/strain conditions and find differences between normal LV and LV with infarct. Echo image data were acquired from five patients with myocardial infarction (I-Group) and five healthy volunteers as control (H-Group). Finite element models were constructed to obtain ventricle stress and strain conditions. Material stiffening and softening were used to model ventricle active contraction and relaxation. Systolic and diastolic material parameter values were obtained by adjusting the models to match echo volume data. Young's modulus (YM) value was obtained for each material stress–strain curve for easy comparison. LV wall thickness, circumferential and longitudinal curvatures (C- and L-curvature), material parameter values, and stress/strain values were recorded for analysis. Using the mean value of H-Group as the base value, at end-diastole, I-Group mean YM value for the fiber direction stress–strain curve was 54% stiffer than that of H-Group (136.24 kPa versus 88.68 kPa). At end-systole, the mean YM values from the two groups were similar (175.84 kPa versus 200.2 kPa). More interestingly, H-Group end-systole mean YM was 126% higher that its end-diastole value, while I-Group end-systole mean YM was only 29% higher that its end-diastole value. This indicated that H-Group had much greater systole–diastole material stiffness variations. At beginning-of-ejection (BE), LV ejection fraction (LVEF) showed positive correlation with C-curvature, stress, and strain, and negative correlation with LV volume, respectively. At beginning-of-filling (BF), LVEF showed positive correlation with C-curvature and strain, but negative correlation with stress and LV volume, respectively. Using averaged values of two groups at BE, I-Group stress, strain, and wall thickness were 32%, 29%, and 18% lower (thinner), respectively, compared to those of H-Group. L-curvature from I-Group was 61% higher than that from H-Group. Difference in C-curvature between the two groups was not statistically significant. Our results indicated that our modeling approach has the potential to determine in vivo ventricle material properties, which in turn could lead to methods to infer presence of infarct from LV contractibility and material stiffness variations. Quantitative differences in LV volume, curvatures, stress, strain, and wall thickness between the two groups were provided.

A Novel Insight into the Role of Entry Tears in Type B Aortic Dissection: Pressure Measurements in an in Vitro Model

2017 ◽  
Vol 40 (10) ◽  
pp. 563-574 ◽  
Author(s):  
Stefania Marconi ◽  
Ettore Lanzarone ◽  
Hector De Beaufort ◽  
Michele Conti ◽  
Santi Trimarchi ◽  
...  
Keyword(s):  
False Lumen ◽  
Patient Characteristics ◽  
Acute Type ◽  
Type B ◽  
Type B Dissection ◽  
Vitro Model ◽  
Insight Into

Introduction Predicting aortic growth in acute type B dissection is fundamental in planning interventions. Several factors are considered to be growth predictors in the literature and, among them, size and location of entry tears have been recognized to particularly influence the false lumen pressure. In this study, we develop an in vitro setting to analyze the actual impact of size and location of the entry tears on false lumen pressure, in the absence of other confounding factors such as the deformability of the aortic wall. Methods We formalize some indexes that synthetically describe the false lumen pressure with respect to the true lumen pressure. Then, we experimentally derive their values in several configurations of the in vitro setting, and we look for trends in the indexes with respect to the size and location of entry tears. Results: Results show that the tears have a relevant impact on the false lumen pressure, but that their size and location alone are not enough to explain the phenomena observed in vivo. Conclusions To predict the behavior of acute type B dissection, we therefore recommend not limiting to size and location, as many effects may derive from the interactions between these parameters and other patient characteristics.

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