Young A A, Fayad Z A, Axel L
Department of Physiology, School of Medicine, University of Auckland, New Zealand.
Am J Physiol. 1996 Dec;271(6 Pt 2):H2677-88. doi: 10.1152/ajpheart.1996.271.6.H2677.
We describe a method for reconstructing the three-dimensional motion and deformation of the midwall surface of the right ventricular free wall (RVFW) using magnetic resonance tissue tagging. Tag points were defined where the tag stripes intersected the midwall contour and were tracked through systole in both short- and long-axis images. A finite-element model of the midwall surface of the RVFW was constructed to fit the midwall shape at end diastole. The model was then deformed to each subsequent frame by fitting the tag displacements and midwall contour locations. The method was applied to two human studies, a normal subject and a patient with right ventricular hypertrophy. The root mean squared error between model tag planes and tracked tag points was 0.70 mm for the normal heart (180 points) and 0.67 mm for the hypertrophic heart (52 points), both less than the image pixel size of approximately 1.0 mm. The differences in contraction patterns were visualized between the two studies. We conclude that this method allows accurate, noninvasive measurement of in vivo RVFW deformation.
我们描述了一种使用磁共振组织标记重建右心室游离壁（RVFW）中壁表面三维运动和变形的方法。标记点定义为标记条纹与中壁轮廓的交点，并在短轴和长轴图像的整个收缩期进行跟踪。构建了RVFW中壁表面的有限元模型，以拟合舒张末期的中壁形状。然后通过拟合标记位移和中壁轮廓位置，将模型变形到每个后续帧。该方法应用于两项人体研究，一名正常受试者和一名右心室肥厚患者。正常心脏（180个点）模型标记平面与跟踪标记点之间的均方根误差为0.70mm，肥厚心脏（52个点）为0.67mm，均小于约1.0mm的图像像素大小。两项研究之间收缩模式的差异得以可视化。我们得出结论，该方法能够准确、无创地测量体内RVFW变形。
