一种心肌应变图的快速绘制方法

摘要

灰度B超图显示心脏的解剖结构，应变图可反映心肌的力学信息。心肌应变图与心脏灰度B超图混叠显示，有助于观察各阶段心肌组织的形态学及力学上的变化。提出一种心肌彩色应变图覆盖到心脏灰度B超图的快速绘制方法，即整体映射方法。采用Sonix RP超声系统扫描正常成年男性心脏6 s，保存左心室长轴的超声射频信号，经过重建灰度B超图像、计算位移图及应变图、勾画心肌的区域、彩色编码应变值等处理步骤，将心肌应变图整体映射到心脏灰度B超图上相应的位置，完成灰度B超图与彩色应变图混叠显示。实验结果：该方法绘制时间短，心肌勾画区域为1×106个像素点时，彩色应变图的绘制时间约为0.24 s，心肌勾画区域为4×106个像素点时，彩色应变图的绘制时间约为2.4 s。说明提出的心肌应变图的整体映射绘制方法，费时少，可以用于实现实时观察心肌的形状和弹性信息。%The grayscale B-mode ultrasound image displays the anatomic structure of the heart, while the strain map reflects the mechanical information of the myocardium.The combination of the myocardial color-coded strain map with the grayscale B-mode image benefits the detection of alterations in the myocardium.Objective:This study proposed a fast mapping method of myocardial strain image superimposed onto the grayscale B-mode ultrasound im-age, i.e.the overall mapping method.Methods:The heart of a health adult male was scanned using Sonix RP ul-trasound system for 6 seconds.The ultrasonic RF signals of the left ventricular long-axis view of the heart were re-corded for reconstruction of the B-mode image.The displacement and strain maps of the myocardium were obtained respectively using the method of dynamic estimation and analytic minimization and the polynomial linear regression. Then, the color-coded strain map of the myocardium was overall superimposed on the grayscale B-mode ultrasound image.Results:The results indicate that the proposed method in this study is time-saving.To map the strain image over the myocardial region containing 1 ×106 pixels, it only took 0.24 s.The mapping time increases with increase of the number of the myocardial region.It took 2.4 s for a myocardial region of 4 ×106 pixels.Conclusion: The proposed method is time-saving and has potentials to observe the deformation and elasticity of the myocardium in re-al time.