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

外周血管疾病（PVD）是由外周（通常是下肢和足部）血液供应不足引起的显著发病率，包括最终截肢。无症状病例和广泛的潜在疾病使PVD的诊断复杂化，包括与动脉粥样硬化相关的大动脉闭塞，与糖尿病，高血压相关的微血管疾病等。目前的诊断工具，包括踝臂指数和双超声，提供了大血管形态和血流动力学的信息。然而，由PVD引起的真正问题，即向外周输送氧气不足，并没有直接评估。我们建议用多光谱光声断层扫描（MSOT）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生物医学诊断方式。通过光脉冲沉积在组织中的能量使吸收器膨胀，产生向外传播的超声波，可以无创地检测到。这使得高分辨率的超声光学成像可以达到皮肤下几厘米的深度。血红蛋白是组织中光的主要吸收剂，因此光声成像解决了血液和血管系统。多光谱光声断层扫描（MSOT）使用多个激发波长来量化特定的吸收剂，如血红蛋白的不同氧合状态，根据他们的光谱。我们计划应用MSOT动态成像疑似PVD患者的小腿和足部血管系统，包括大动脉闭塞和微血管疾病，提供血红蛋白浓度和氧合等氧输送测量。此外，我们将通过纵向测量和血管成形术过程中应用MSOT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.