CFD analysis in an anatomically realistic coronary artery model based on non-invasive 3D imaging: comparison of magnetic resonance imaging with computed tomography

Abstract

Computational fluid dynamics (CFD) methods based on in vivo three-dimensional vessel reconstructions have recently been shown to provide prognostically relevant hemodynamic data. However, the geometry reconstruction and the assessment of clinically relevant hemodynamic parameters may depend on the used imaging modality. This study compares geometric reconstruction and calculated wall shear stress (WSS) values based on magnetic resonance imaging (MRI) and computed tomography (CT). Both imaging methods were applied to a same 2.5-fold upscale silicon model of the left coronary artery (LCA) main bifurcation. The original model is an optically digitized post mortem vessel cast. This digitized geometry is considered as a "gold standard" or original geometry for the MRI versus CT comparative study. The use of the upscale model allowed generating a high resolution CT raw data set with voxel size of 0.156 x 0.156 x 0.36 mm(3) and a high resolution MRI data set with an equivalent voxel size of 0.196 x 0.196 x 0.196 mm(3) for corresponding in vivo conditions. MRI based reconstruction achieved a mean Hausdorff surface distance of 0.1 mm to the original geometry. This is 2.5 times better than CT based reconstruction with mean Hausdorff surface distance of 0.252 mm. A comparison of the calculated mean WSS shows good correlation (r = 0.97) and good agreement among the three modalities with a WSS of 0.65 Pa in the original model, of 0.68 Pa in the CT based model and of 0.67 Pa in the MRI based model.

Efficient implementation of the proper outlet flow conditions in blood flow simulations through asymmetric arterial bifurcations

“…However, a quantitative comparison is difficult to be made, as they have used a considerably different input flux, more broadly distributed over time. A similar range of wall shear rates is also reported by Goubergrits et al [64]. Regarding qualitative changes in the WSS values observed over the LAD and LCX arteries in the above studies, suffice it to mention that similar trends to those observed in this work have been reported, with the maximum shear stress obtained at the peak of the pulse at the end of the LCX (compare our Figure 6(b) for t = 0.075 with the middle row, last column in Figure 4 of [42] and Figure 7 of [64]).…”

Coronary Artery WSS Profiling Using a Geometry Reconstruction Based on Biplane Angiography

“…Note that similar model (silicon model based on the same original geometry, but with other up scaling) was also acquired by CT and MRI in our earlier study. 16 All techniques are able to reproduce LCA geometry well with an error that is about the resolution of the respective technique (voxel size). For biplane angiography, the voxel size definition is of cause not possible.…”

“…Though wall thickness is an important parameter in assessing atherosclerosis it has no direct impact on the calculation of WSS. Recently, we evaluated a simplified approach to 3D-modelling of the geometry of coronary arteries based on biplane angiograms only 16 that allows retrospective studies in angiographic databases. Improvements in imaging modalities (multi-slice CT and MRI) provide alternative noninvasive data sources.…”

“…3,10 The proposed study compares the reconstructed geometry and the calculated WSS values based on biplane angiography of a phantom model of the anatomically realistic left coronary artery (LCA) bifurcation that was used also in our previous study. 16 The results of this study serve for validation of the coronary artery reconstruction techniques including the used reconstruction software and to study the impact of geometric uncertainties on the analysis of hemodynamic parameters. The main scope of this study was to demonstrate the suitability of biplane-based reconstructions for WSS profiling studies in coronary arteries.…”

Fabrication of rigid and flexible refractive-index-matched flow phantoms for flow visualisation and optical flow measurements

“…These errors are in the range of the resolution of the CT scan. When translated to in vivo size, the mean surface distance error amounts to approximately 90 lm, which is smaller than that reported by Goubergrits et al (2009) from biplane angiography (232 lm) or Doorly et al (2008) (290 lm), and similar to that reported in (Goubergrits et al 2008) from MRI (100 lm).…”