Deformation analysis of 3D tagged cardiac images using an optical flow method.
Deformation analysis of 3D tagged cardiac images using an optical flow method.
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DOI：
10.1186/1532-429x-12-19
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发表时间：
2010-03-30
期刊：
影响因子：
--
通讯作者：
Dougherty L
中科院分区：
文献类型：
--
作者：
Xu C;Pilla JJ;Isaac G;Gorman JH 3rd;Blom AS;Gorman RC;Ling Z;Dougherty L
本研究提出并验证了一种使用三维心血管磁共振（CMR）组织标记序列和三维光流法（OFM）测量心肌三维应变的方法。首先，开发了一个三维标签MR序列，并利用模拟变形的幻影图像对序列参数和3D OFM进行了优化。该方法随后在体内得到验证，并用于定量正常绵羊左心室功能。在幻影研究中，优化成像和OFM参数在x （RMSx = 0.62像素（0.43 mm））、y （RMSy = 0.64像素（0.45 mm））和z （RMSz = 0.68像素（1 mm））方向上的估计位移和已知位移之间分别产生亚像素的均方根误差（RMS）。体内验证表明，人工跟踪标签交叉点测量的位移与3D OFM产生的位移之间具有良好的相关性（R≥0.98）。即使在幻影图像中加入20%高斯噪声，也能保持技术性能。此外，与2D跟踪相比，3D心脏运动的3D跟踪导致平面内跟踪误差减少51%。体内功能研究表明，最大的壁增厚在侧壁最大，从心尖和基底向中心室区增加。区域变形模式与先前的左室功能研究一致。提出了一种快速测量三维左室壁变形的新方法，该方法具有高的面内和透面分辨率。
This study proposes and validates a method of measuring 3D strain in myocardium using a 3D Cardiovascular Magnetic Resonance (CMR) tissue-tagging sequence and a 3D optical flow method (OFM). Initially, a 3D tag MR sequence was developed and the parameters of the sequence and 3D OFM were optimized using phantom images with simulated deformation. This method then was validated in-vivo and utilized to quantify normal sheep left ventricular functions. Optimizing imaging and OFM parameters in the phantom study produced sub-pixel root-mean square error (RMS) between the estimated and known displacements in the x (RMSx = 0.62 pixels (0.43 mm)), y (RMSy = 0.64 pixels (0.45 mm)) and z (RMSz = 0.68 pixels (1 mm)) direction, respectively. In-vivo validation demonstrated excellent correlation between the displacement measured by manually tracking tag intersections and that generated by 3D OFM (R ≥ 0.98). Technique performance was maintained even with 20% Gaussian noise added to the phantom images. Furthermore, 3D tracking of 3D cardiac motions resulted in a 51% decrease in in-plane tracking error as compared to 2D tracking. The in-vivo function studies showed that maximum wall thickening was greatest in the lateral wall, and increased from both apex and base towards the mid-ventricular region. Regional deformation patterns are in agreement with previous studies on LV function. A novel method was developed to measure 3D LV wall deformation rapidly with high in-plane and through-plane resolution from one 3D cine acquisition.