Remote Intravascular Pressure Sensing using Ultrasound

项目总结 许多临床上有意义的肝硬变并发症都是由于门脉增大引起的。 高血压。门静脉压力的直接测量是有创的，需要进行大量的操作 经验。因此，一种准确、无创的门静脉压力测量方法具有 有可能降低风险，使临床医生能够改善肝病患者的常规体检。到那时候 最后，我们小组有令人兴奋的数据表明，组织中的远程压力传感可以使用 新型造影剂和定制技术，我们将其命名为组织血管内压估计 超声波(TIPE-US)。最近的进展是相变造影剂(PCCA)的开发， 其在环境条件下是稳定的液体纳米液滴，但可以选择性地使用脉冲 超声能量经历相变成为可使用超声检测的高回声微泡 成像。我们小组的几项研究一直表明，PCCA所需的超声能量 活化是高度线性的，并且依赖于周围流体的静水压力。因此，我们 假设这些PCCA和实时超声成像技术可以用于远程血管内 门脉高压的压力传感和检测。拟议的研究项目的总体目标是 开发下一代TIPE-US成像系统和方法，用于血管成像的远程压力传感 组织。该项目的第一个目标是实现新的TIPE-US功能和对 可编程超声波扫描仪。在第二个目标中，我们将评估定制和单分散的使用 PCCA可在TIPE-US成像过程中最大限度地生成和量化传感信号。我们还将进行 首次使用已建立的门脉高压动物模型进行TIPE-US体内试验。

PROJECT SUMMARY Many of the clinically significant complications of liver cirrhosis arise as a consequence of increased portal hypertension. Direct measurement of portal venous pressures is invasive and requires significant procedural experience. Therefore, an accurate and noninvasive method for measurement of portal venous pressure has the potential to reduce risk and enable clinicians to improve the routine workup of patients with liver disease. To that end, our group has exciting data that suggests remote pressure sensing in tissue can be performed using a novel contrast agent and custom technology we have termed tissue intravascular pressure estimation using ultrasound (TIPE-US). A recent advance was in the development of a phase-change contrast agent (PCCA), which is a stabilized liquid nanodroplet under ambient conditions but can be selectively activated using pulsed ultrasound energy to undergo a phase transition into a highly echogenic microbubble detectable using ultrasound imaging. Several studies by our group have consistently shown that the ultrasound energy required for PCCA activation is highly linear and dependent on the hydrostatic pressure of the surrounding fluid. Therefore, we hypothesize that these PCCAs and real-time ultrasound imaging techniques can be used for remote intravascular pressure sensing and detection of portal hypertension. The overarching goal of the proposed research project is to develop a next-generation TIPE-US imaging system and method for remote pressure sensing in vascularized tissue. The first aim of this project is to implement new TIPE-US functionality and feedback control on a programmable ultrasound scanner. In the second aim, we will evaluate the use of custom and monodisperse PCCAs to maximize sensing signal generation and quantification during TIPE-US imaging. We will also conduct the first in vivo tests of TIPE-US using an established animal model portal hypertension.