A spatially-distributed computational model to quantify behaviour of contrast agents in MR perfusion imaging.
A spatially-distributed computational model to quantify behaviour of contrast agents in MR perfusion imaging.
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DOI：
10.1016/j.media.2014.07.002
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发表时间：
2014-10
影响因子：
10.9
通讯作者：
Smith, N. P.
中科院分区：
文献类型：
--
作者：
Cookson, A. N.;Lee, J.;Michler, C.;Chabiniok, R.;Hyde, E.;Notdsletten, D.;Smith, N. P.
关键词：
提出了心肌磁共振灌注成像的有限元模型。对健康组织和患病组织的模型进行参数空间研究。临床指标对于血管外扩散率的变化是非单调的。信号上升是比峰值信号值更稳健的临床指标。造影剂增强磁共振 (MR) 灌注成像可提供冠状循环缺陷的早期、非侵入性指示。然而，造影剂特性、生理状态和成像协议的巨大变化意味着图像采集的优化很难实现。这种情况促进了计算框架的发展，反过来，该框架能够有效映射该参数空间，为临床环境中灌注成像的优化提供有价值的信息。为此，开发了毛细血管血流的单室多孔介质模型，该模型与标量传输模型相结合，以表征血池和自由扩散造影剂的行为，其特征在于它们能够穿过毛细血管壁扩散到细胞外空间。使用健康和患病心肌的二维模型对无量纲方程进行参数空间研究，检查系统行为对佩克莱特数、达姆克勒数 (Da)、扩散率和流体孔隙率的敏感性。假设线性 MR 信号响应模型，计算样本浓度时间序列数据，并量化这些信号的临床相关特性对模型参数的敏感性。就 Damköhler 数而言，上坡值和峰值都显示出显着的非单调行为，这些特性在与当前使用的造影剂相关的参数范围内显示出高度的敏感性。然而，结果表明，信号上斜率是灌注量化更稳健和更具辨别力的指标，特别是与灌注缺陷大小相关。最后，在非线性信号响应、费米反卷积流量量化和灌注储备指数的背景下对结果进行了检查，这表明不存在单一的最佳造影剂参数集，而是应根据要使用的特定成像协议和后处理方法定制造影剂。
A finite element model of myocardial MR perfusion imaging is proposed. A parameter space study is performed for models of both healthy and diseased tissue. Clinical metrics non-monotonic with respect to changes in extra-vascular diffusivity. Signal upslope a more robust clinical metric than peak signal value. Contrast agent enhanced magnetic resonance (MR) perfusion imaging provides an early, non-invasive indication of defects in the coronary circulation. However, the large variation of contrast agent properties, physiological state and imaging protocols means that optimisation of image acquisition is difficult to achieve. This situation motivates the development of a computational framework that, in turn, enables the efficient mapping of this parameter space to provide valuable information for optimisation of perfusion imaging in the clinical context. For this purpose a single-compartment porous medium model of capillary blood flow is developed which is coupled with a scalar transport model, to characterise the behaviour of both blood-pool and freely-diffusive contrast agents characterised by their ability to diffuse through the capillary wall into the extra-cellular space. A parameter space study is performed on the nondimensionalised equations using a 2D model for both healthy and diseased myocardium, examining the sensitivity of system behaviour to Peclet number, Damköhler number (Da), diffusivity ratio and fluid porosity. Assuming a linear MR signal response model, sample concentration time series data are calculated, and the sensitivity of clinically-relevant properties of these signals to the model parameters is quantified. Both upslope and peak values display significant non-monotonic behaviour with regard to the Damköhler number, with these properties showing a high degree of sensitivity in the parameter range relevant to contrast agents currently in use. However, the results suggest that signal upslope is the more robust and discerning metric for perfusion quantification, in particular for correlating with perfusion defect size. Finally, the results were examined in the context of nonlinear signal response, flow quantification via Fermi deconvolution and perfusion reserve index, which demonstrated that there is no single best set of contrast agent parameters, instead the contrast agents should be tailored to the specific imaging protocol and post-processing method to be used.
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影响因子：
2.4
作者：
Cookson AN;Lee J;Michler C;Chabiniok R;Hyde E;Nordsletten DA;Sinclair M;Siebes M;Smith NP
通讯作者：
Smith NP
DOI：
10.1186/1532-429x-12-28
发表时间：
2010-05-13
期刊：
Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance
影响因子：
--
作者：
Kelle S;Graf K;Dreysse S;Schnackenburg B;Fleck E;Klein C
通讯作者：
Klein C
影响因子：
--
作者：
HUYGHE, JM;ARTS, T;RENEMAN, RS
通讯作者：
RENEMAN, RS
影响因子：
3.3
作者：
Di Bella, EVR;Parker, DL;Sinusas, AJ
通讯作者：
Sinusas, AJ
影响因子：
3.8
作者：
Jerosch-Herold, M;Wilke, N;Wilson, RF
通讯作者：
Wilson, RF