Aneurysm Volume-to-Ostium Area Ratio: A Parameter Useful for Discriminating the Rupture Status of Intracranial Aneurysms
ABSTRACT Slow or stagnant flow is a hemodynamic feature that has been linked to the risk of aneurysm rupture.
To assess the potential value of the ratio of the volume of an aneurysm to the area of its ostium (VOR) as an indicator of intra-aneurysmal slow flow and, thus, in turn, the risk of rupture.
Using a sample defined from internal databases, a retrospective analysis of aneurysm size, aspect ratio (AR), and VOR was performed on a series of 155 consecutive aneurysms having undergone 3-dimensional digital subtraction angiography as a part of their evaluation. Measurements were obtained from 3-dimensional digital subtraction angiography studies using commercial software. Aneurysm size, AR, and VOR were correlated with rupture status (ruptured or unruptured). A multiple logistic regression model that best correlated with rupture status was generated to evaluate which of these parameters was the most useful to discriminate rupture status. This model was validated using an independent database of 62 consecutive aneurysms acquired outside the retrospective study interval.
VOR showed better discrimination for rupture status than did size and AR. The best logistic regression model, which included VOR rather than size or AR, determined rupture status correctly in 80.6% of subjects. The reproducibility calculating AR and VOR was excellent.
Determination of VOR was easily done and reproducible using widely available commercial equipment. It may be a more robust parameter to discriminate rupture status than AR.
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ABSTRACT: The purpose of this study is to evaluate the association of the location and geometric parameters of intracranial aneurysm with the risk of rupture. A retrospective study consisted of 284 patients diagnosed with saccular intracranial aneurysm between January 2009 and May 2013 at Wuxi Third People's Hospital was conducted. 3D digital subtraction angiography images from all patients (240 ruptured, 44 unruptured) were obtained and analyzed. The location of the aneurysms and the 3D geometric parameters including the aneurysm depth, the neck size, diameter of the parent artery, aneurysm angle, aspect radio, size ratio, and the neck-to-parent-artery ratio (NPR) were compared between ruptured and unruptured groups. Results: In ruptured group, anterior communicating artery, posterior communicating artery (PCoA), and the bifurcation of internal carotid artery (ICA) were the top three locations for aneurysm occurrence, accounting for 40.00, 30.42, and 12.08 % respectively. While in the unruptured group, top three locations were PCoA (36.36 %), posterior cerebral circulation (18.18 %), and the bifurcation of the ICA (15.91 %). Distribution of aneurysm location is significantly different (p < 0.05) between ruptured and unruptured aneurysms. For the 3D geometric parameters characterizing aneurysm, aneurysm depth (p < 0.05), parent artery diameter (p < 0.05), aneurysm angle (p < 0.01), aspect ratio (p < 0.01), and size ratio (p < 0.01) all showed a significant difference between ruptured and unruptured group. No difference was found in the neck size and the NPR ratio between the two groups. 3D geometric parameters such as aneurysm depth, parent artery diameter, aneurysm angle, aspect ratio, and size ratio can be helpful in evaluating the rupture risk of saccular intracranial aneurysm for a better prevention and prognosis.Cell Biochemistry and Biophysics 06/2014; 70(2). DOI:10.1007/s12013-014-0074-6 · 2.38 Impact Factor
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ABSTRACT: As an example of enhancing information in clinical image data by computational methods, simulating hemodynamics in cerebral aneurysms by means of computational fluid dynamics (CFD) is currently a topic of active research. Challenges consist in translating this engineering technology into clinical research, validating the simulations and addressing a potential clinical value of the results. In this preliminary study, we demonstrate the use of phase contrast magnetic resonance imaging (pcMRI) for assessing the reliability of CFD results. For six cerebral aneurysms where intra-aneurysmal velocity information was available by 2D pcMRI, steady CFD simulations with constant inflow were performed using a dedicated CFD prototype system. Major features of the velocity patterns derived from pcMRI were compared to those obtained with the CFD. Good qualitative agreement between measured (2D pcMRI) and simulated (CFD) features of the intra-aneurysmal velocity patterns were obtained. These findings are discussed in the broader framework of the expectations towards CFD simulations in a clinical research setting. Computational simulations reproduce major features of measured velocity patterns in cerebral aneurysms. Looking forward, these simulations need to be refined towards specific applications in clinical research.04/2014; 4(2):207-12. DOI:10.3978/j.issn.2223-3652.2014.02.07
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ABSTRACT: In contrast to size, the association of morphological characteristics of intracranial aneurysms with rupture has not been established in a systematic manner. We present an analysis of the morphological variables that are associated with rupture in anterior communicating artery aneurysms to determine site-specific risk variables. One hundred and twenty-four anterior communicating artery aneurysms were treated in a single institution from 2005 to 2010, and CT angiograms (CTAs) or rotational angiography from 79 patients (42 ruptured, 37 unruptured) were analyzed. Vascular imaging was evaluated with 3D Slicer© to generate models of the aneurysms and surrounding vasculature. Morphological parameters were examined using univariate and multivariate analysis and included aneurysm volume, aspect ratio, size ratio, distance to bifurcation, aneurysm angle, vessel angle, flow angle, and parent-daughter angle. Multivariate logistic regression revealed that size ratio, flow angle, and parent-daughter angle were associated with aneurysm rupture after adjustment for age, sex, smoking history, and other clinical risk factors. Simple morphological parameters such as size ratio, flow angle, and parent-daughter angle may thus aid in the evaluation of rupture risk of anterior communicating artery aneurysms.PLoS ONE 11/2013; 8(11):e79635. DOI:10.1371/journal.pone.0079635 · 3.53 Impact Factor