基于超声射频信号的女性盆底功能障碍定量评价方法研究

Female pelvic floor dysfunction disease (FPFD) is one of the most common chronic diseases, and almost one third of premenopausal women and half of postmenopausal women suffer from symptoms of FPFD. It is believed that FPFD occurs when the biomechanical properties of the pelvic supportive structures progressively decrease, however, there are rare of such studies assessing the biomechanical properties. The pelvic floor muscles are typical anisotropic viscoelastic tissues. They are difficult to be palpated as they are obscured by the pelvis. Therefore, conventional tissue elasticity imaging techniques, including ultrasound and MR elastography, which rely on a mechanical low-frequency vibrator and a tissue-isotropic assumption, cannot be applied to evaluate the pelvic floor muscles directly. Our study aims at the quantitative measurement of the viscoelasticity of female pelvic floor muscles. We propose a new method based on ultrasound RF signal processing techniques, to investigate the following key issues: 1) the beam control algorithm with consideration of ultrasound propagating through multi-layers of tissues, 2) the stimulation of directional shear wave using acoustic radiation force in anisotropic medium, and 3) the propagation of shear wave in anisotropic medium along and perpendicular the orientation of muscle fibers. We propose in this study a new method for shear wave velocity measurement based on the ultra-high frame rate transient M-mode ultrasound. After tempo-spatial analysis of RF signals in M sequences, shear wave velocity dispersion characteristics can be observed and used to extract the shear modulus and viscosity coefficient of muscles. Our study provides a new and reliable tool for clinic, not only for FPFG quantitative diagnosis, but also provides an important means for basic research of FPFD pathogenesis.

女性盆底功能障碍性疾病（FPFD）是严重影响女性身心健康的五种最常见慢性疾病之一，其根本性原因是盆底支持组织生物力学性质的进行性减退。FPFD的早期诊断和康复评估依赖于盆底肌力学性质的定量测量，然而，目前尚未见其粘弹性活体测量的报道。 盆底肌是典型的各向异性粘弹性组织，受骨盆遮挡，位置隐匿。现有的组织弹性成像方法无法直接应用。 本项目针对女性盆底肌的特殊应用，提出一种基于超声射频信号处理的粘弹性测量方法，重点研究声波通过多层组织后的波束控制算法，实现各向异性的生物组织内剪切波的定点和定向激励，研究剪切波传播模式与肌纤维排列分布的关系，提出基于超高帧频瞬态M型超声的剪切波速测量方法，并从剪切波速的弥散特性中拟合盆底肌的剪切模量和粘性系数，从而为临床提供一种全新而可靠的工具，不仅可为FPFG提供定量准确的诊断方法和康复疗效评估手段，也可从组织生物力学角度为探讨FPFD的发病机制提供基础。

女性盆底功能障碍性疾病（FPFD）是严重影响女性身心健康的五种最常见慢性疾病之一，其根本性原因是盆底支持组织生物力学性质的进行性减退。FPFD 的早期诊断和康复评估依赖于盆底肌力学性质的定量测量，然而，目前尚未见其粘弹性活体测量的报道。盆底肌是典型的各向异性粘弹性组织，受骨盆遮挡，位置隐匿。现有的组织弹性成像方法无法直接应用。.在本项目中，我们提出基于超声的无创客观的肌肉运动分析方法，可以采集分析盆底肌在静息、快速缩放以及最大肌力保持等不同状态下的解剖学参数和剪切弹性模量。针对肌肉的各向异性特性，研究了新型的超声波束调控和合成方法、以及声辐射力激励方法，并利用同个超声探头实现了声辐射力激励和快速成像功能，通过自行设计制备的各向异性仿体验证了新算法的可靠性和准确性之后，招募了女性盆底功能障碍志愿者，采集分析了临床数据，并提取出有诊断意义的生物力学参数，证明了本项目的方法可以为女性盆底功能障碍提供定量准确的诊断方法和康复疗效评估手段，也可从组织生物力学角度为探讨性盆底功能障碍的发病机制提供基础。