一种心肌应变图的快速绘制方法

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1×10~6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4×10~6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。

A Fast Mapping Method of Myocardial Strain Image

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 image, i.e. the overall mapping method. Methods: The heart of a health adult male was scanned using Sonix RP ultrasound system for 6 seconds. The ultrasonic RF signals of the left ventricular long-axis view of the heart were recorded 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 0.24s. The mapping time increases with increase of the number of the myocardial region. It took 2.4s for a myocardial region of 4×106pixels. Conclusion: The proposed method is time-saving and has potentials to observe the deformation and elasticity of the myocardium in real time.