基于运动学模型的分析框架，用于轴向压缩凝胶模型的 3D Cine-DENSE 验证，并在绵羊前壁心尖梗死前后的应用。

A kinematic model-based analysis framework for 3D Cine-DENSE-validation with an axially compressed gel phantom and application in sheep before and after antero-apical myocardial infarction.

机构信息

Veterans Affairs Medical Center, San Francisco, California, USA.

Department of Biomedical Engineering, University of Berkeley, Berkeley, California, USA.

出版信息

Magn Reson Med. 2021 Oct;86(4):2105-2121. doi: 10.1002/mrm.28775. Epub 2021 Jun 6.

DOI:10.1002/mrm.28775

PMID:34096083

Abstract

PURPOSE

Myocardial strain is increasingly used to assess left ventricular (LV) function. Incorporation of LV deformation into finite element (FE) modeling environment with subsequent strain calculation will allow analysis to reach its full potential. We describe a new kinematic model-based analysis framework (KMAF) to calculate strain from 3D cine-DENSE (displacement encoding with stimulated echoes) MRI.

METHODS

Cine-DENSE allows measurement of 3D myocardial displacement with high spatial accuracy. The KMAF framework uses cine cardiovascular magnetic resonance (CMR) to facilitate cine-DENSE segmentation, interpolates cine-DENSE displacement, and kinematically deforms an FE model to calculate strain. This framework was validated in an axially compressed gel phantom and applied in 10 healthy sheep and 5 sheep after myocardial infarction (MI).

RESULTS

Excellent Bland-Altman agreement of peak circumferential (E ) and longitudinal (E ) strain (mean difference = 0.021 ± 0.04 and -0.006 ± 0.03, respectively), was found between KMAF estimates and idealized FE simulation. E had a mean difference of -0.014 but larger variation (±0.12). Cine-DENSE estimated end-systolic (ES) E , E and E exhibited significant spatial variation for healthy sheep. Displacement magnitude was reduced on average by 27%, 42%, and 56% after MI in the remote, adjacent and MI regions, respectively.

CONCLUSIONS

The KMAF framework allows accurate calculation of 3D LV E and E from cine-DENSE.

摘要

目的

心肌应变越来越多地用于评估左心室（LV）功能。将 LV 变形纳入具有后续应变计算的有限元（FE）建模环境中，将使分析发挥其全部潜力。我们描述了一种新的基于运动学模型的分析框架（KMAF），用于从 3D 电影密度（位移编码与受激回波）MRI 计算应变。

方法

电影密度允许以高空间精度测量 3D 心肌位移。KMAF 框架使用电影心血管磁共振（CMR）来促进电影密度分段，插值电影密度位移，并通过运动学变形 FE 模型来计算应变。该框架在轴向压缩凝胶模型中进行了验证，并应用于 10 只健康绵羊和 5 只心肌梗死（MI）后的绵羊。

结果

KMAF 估计值与理想化 FE 模拟之间的峰值周向（E ）和纵向（E ）应变的极好 Bland-Altman 一致性（平均差异分别为 0.021 ± 0.04 和 -0.006 ± 0.03）。E 的平均差异为 -0.014，但差异较大（±0.12）。电影密度估计的收缩末期（ES）E 、E 和 E 在健康绵羊中表现出显著的空间变化。MI 后，远程、相邻和 MI 区域的位移幅度平均分别降低了 27%、42%和 56%。