An Investigation on Noninvasive Measurement of Transmural Distribution of Myocardial Systolic Function and Diastolic Properties Using Ultrasound

对于严重的心脏疾病，心肌的不同透壁层在收缩强度方面具有透壁异质性。测量这种跨壁异质性具有足够的空间分辨率的方法从来没有被开发。本研究开发了一种通过测量心肌厚度或其速度的二维变化来无创测量心肌收缩/舒张异质性的方法及其测量系统。在此基础上，提出了一种新的测量心肌粘弹性的方法，并通过基础实验和在体实验证实了其原理：1.本研究开发了一种通过测量心肌厚度变化或速度变化来无创测量心肌收缩/舒张不均匀性的方法及其测量系统; 2.在基础实验的基础上，采用硅橡胶球壳，测量了其物理参数，并对测量结果进行了分析和比较 关于我们 作为仿心脏体模，验证了该方法测量的准确性。3.此外，本研究还发展了以下新方法，用于无创测量心脏舒张初期的心肌粘弹性和成像弹性波传播中的跨壁不均匀性。该方法适用于健康受试者和心脏病患者。通过该方法，能够以充分的再现性成功地检测心壁的速度信号。在这项研究中，脉冲波几乎同时测量约160点设置沿着心脏壁在一个足够高的帧速率。连续的空间相位分布，通过傅立叶变换的测量波，清楚地揭示了波的传播沿着心脏壁的第一次。基于这一现象，我们发展了一种方法来测量心肌粘弹性在体内使用的模型中的兰姆波传播的粘弹性板。该方法具有无创性评价心肌粘弹性的潜力。少

For the serious heart diseases, the different transmural layers of the myocardium have transmural heterogeneity with respect to the strength of contraction. A method for measuring such transmural heterogeneity with sufficient spatial resolution has never been developed. In this study, a method for noninvasive measurement of the intramyocardial contraction/relaxation heterogeneity by evaluating the change in thickness or its speed in two dimensions and its measurement system were developed. Moreover, a novel method for measuring the myocardial viscoelasticity was developed and its principle was confirmed by the basic experiments and in vivo experiments as follows :1.In this study, a method for noninvasive measurement of the intramyocardial contraction/relaxation heterogeneity by evaluating the change in thickness or its speed in two dimensions and its measurement system were developed.2.Based on the basic experiments using a spherical shell made of silicone rubber, which physical parame … More ters are known, as a heart-mimicking phantom, the accuracy of the measurement of the developed method was confirmed.3.Moreover, this study developed the following novel method for noninvasively measuring the myocardial viscoelasticity at the beginning of diastole and for imaging the transmural heterogeneity in the propagation of the elastic waves. The method was applied to healthy subjects and patients with heart diseases. By this method, a velocity signal of the heart wall can be successfully detected with sufficient reproducibility. In this study, the pulsive waves were measured almost simultaneously at about 160 points set along the heart wall at a sufficiently high frame rate. The consecutive spatial phase distributions, obtained by the Fourier transform of the measured waves, clearly revealed wave propagation along the heart wall for the first time. Based on this phenomenon, we developed a means to measure the myocardial viscoelasticity in vivo using the model of the Lamb wave propagation in a viscoelastic plate. This method has a potential to noninvasively evaluate the myocardial viscoelasticity. Less