Multispectral optoacoustic tomography (MSOT) for clinical diagnosis and therapeutic monitoring of peripheral vascular disease (PVD)

外周血管疾病(PVD)与外周(通常是小腿和脚)的血液供应不足引起的严重发病率有关，包括最终的肢体截肢。PVD的诊断复杂于无症状的病例和广泛的基础疾病，包括动脉粥样硬化相关的大动脉闭塞、糖尿病相关的微血管疾病、高血压等。目前的诊断工具，包括踝臂指数和双功超声，提供了关于大血管形态和血流动力学的信息。然而，PVD造成的真正问题，即向外周输送氧气不足，并未得到直接评估。我们建议用多光谱光声断层成像(MSOT)来诊断PVD患者，它可以提供血管系统的功能图像。光声成像已经成为一种非常有前途的活体生物医学诊断方法。光脉冲在组织中沉积的能量会导致吸入器膨胀，产生向外传播的超声波，可以非侵入性地检测到。这允许在高分辨率的超声波下进行光学成像，最高可达皮肤下几厘米的深度。血红蛋白是组织中对光的主要吸收者，因此光声成像可以分解血液和血管系统。多光谱光声层析成像(MSOT)利用多个激发波长来量化特定的吸收体，如根据它们的光谱来量化血红蛋白的不同氧化状态。我们计划应用MSOT动态成像疑似PVD患者小腿和脚的血管系统，包括大动脉闭塞和微血管疾病，提供氧气输送指标，如血红蛋白浓度和氧合。此外，我们将通过进行纵向测量和在血管成形术过程中应用MSOT来提供实时反馈，来研究治疗监测。

Peripheral vascular disease (PVD) is associated with significant morbidity caused by insufficient blood supply to the periphery (usually lower legs and feet), including ultimate amputation of limbs. Diagnosis of PVD is complicated by asymptomatic cases and a wide range of underlying diseases, including atherosclerosis-related occlusion of large arteries, microvascular disease linked to diabetes, hypertension, et cetera. Current diagnostic tools, including ankle-brachial index and duplex sonography, provide information on large vessel morphology and hemodynamics. However, the real problem caused by PVD, insufficient delivery of oxygen to the periphery, is not directly assessed. We propose to diagnose PVD patients with multispectral optoacoustic tomography (MSOT), which can provide functional images of the vasculature. Optoacoustic imaging has emerged as a highly promising modality for in vivo biomedical diagnostics. Energy deposited in the tissue by pulses of light causes absorbers to expand, giving rise to ultrasound waves that propagate outwards and can be detected noninvasively. This allows optical imaging at the high resolution of ultrasound up to depths of centimeters under the skin. Hemoglobin is a primary absorber of light in tissue, thus optoacoustic imaging resolves blood and vasculature. Multispectral Optoacoustic Tomography (MSOT) uses multiple excitation wavelengths to quantify specific absorbers, such as the different oxygenation states of hemoglobin, according to their spectra. We plan to apply MSOT to dynamically image the vasculature in the lower legs and feet of patients with suspected PVD, including large artery occlusion and microvascular disease, providing measures of oxygen delivery such as hemoglobin concentration and oxygenation. Additionally, we will investigate treatment monitoring, both by performing longitudinal measurements, and by applying MSOT during angioplasty procedures to provide real-time feedback.