Radiotracer-Based Imaging for Quantitative Assessment of Angiosome Perfusion Following Lower Extremity Revascularization

项目摘要 这项工作的长期目标是非侵入性地评估术后足部组织灌注的局部变化。 下肢血管重建术更好地预测靶向治疗的疗效和未来创面发生率 治愈和保肢。外周血管疾病(PVD)是一种下肢动脉粥样硬化性疾病 这影响了800万到1000万美国人，在患有 糖尿病(DM)。除了大血管并发症外，糖尿病患者通常还会出现 下肢微血管疾病，这可能导致足部溃疡、肢体溃疡的高发生率 截肢，以及糖尿病环境中存在的不良治疗结果。当前的成像工具具有局限性 用于评估潜在的微血管疾病，并且没有标准的非侵入性方法来评估 足部三维(3D)血管区域或血管小体内微血管血流的变化， 对PVD患者进行药物治疗。我们提出了一种新的评估血管小体的方法。 糖尿病合并严重肢体缺血(CLI)患者静息状态下的微血管灌流 正在进行血运重建。使用SPECT/CT混合成像，我们将评估微血管灌注 在足部的3D血管小体内，由于先前存在的不可愈合的原因，这些血管小体被定位为直接血管重建 血管小体相对和绝对灌注量的变化与伤口愈合率和肢体愈合速度之间的关系 打捞。这项工作的中心假设是，基于放射性示踪剂的微血管灌注成像可以 在特定的血管区域检测脚部潜在病理生理学的敏感变化，这可以 协助临床医生进行有针对性的血管重建术，同时预测治疗效果和保肢 结果。在目标1中，我们将量化3D血管小体内静息微血管灌注的相对变化。 应用SPECT/CT成像评估针对未愈合创面的血管重建术 糖尿病合并CLI患者血管小体血流变化与创面愈合和保肢的关系 结果。AIM 2将验证动态SPECT/CT成像在量化脑血管疾病系列变化中的作用 在外周动脉闭塞的大型动物模型中骨骼肌的绝对灌注。最后，《目标3》将 将动态SPECT/CT成像转换为患者，以评估该方法的重复性和评估 糖尿病血管重建术中血管小体三维绝对定量血流灌注的价值我们 相信基于放射性示踪剂的成像将允许对受损的足部组织灌注进行高灵敏度的检测 在基线和血运重建后的静息状态下。因此，该成像方法可以 帮助识别有伤口进展或肢体丧失风险的患者，并协助预测治疗结果 在PVD患者中。

Project Abstract The long-term goal of this work is to non-invasively evaluate regional changes in foot tissue perfusion following lower extremity revascularization to better predict efficacy of targeted treatment and future rates of wound healing and limb salvage. Peripheral vascular disease (PVD) is an atherosclerotic disease of the lower limbs that affects 8 to 10 million Americans, and is more prevalent and progresses more quickly in patients with diabetes mellitus (DM). In addition to macrovascular complications, DM patients commonly present with microvascular disease of the lower extremities, which may contribute to high rates of foot ulceration, limb amputation, and poor treatment outcomes that exist in the setting of DM. Current imaging tools have limitations for assessing underlying microvascular disease and there is no standard non-invasive approach to evaluate changes in microvascular perfusion in three-dimensional (3D) vascular territories of the feet, or angiosomes, following medical treatment in PVD patients. We propose a novel approach for evaluating angiosome microvascular perfusion under resting conditions in DM patients with critical limb ischemia (CLI) who are undergoing revascularization. Using hybrid SPECT/CT imaging, we will evaluate microvascular perfusion within 3D angiosomes of the foot that are targeted for direct revascularization due to pre-existing non-healing wounds, and relate changes in relative and absolute angiosome perfusion to rates of wound healing and limb salvage. The central hypothesis of this work is that radiotracer-based imaging of microvascular perfusion can detect sensitive changes in underlying pathophysiology of the foot in specific vascular territories, which can assist clinicians with targeted revascularization while also predicting treatment efficacy and limb salvage outcomes. In Aim 1 we will quantify relative changes in resting microvascular perfusion within 3D angiosomes of the foot using SPECT/CT imaging to evaluate revascularization procedures targeted at non-healing wounds in DM patients with CLI, and relate changes in angiosome perfusion to wound healing and limb salvage outcomes. Aim 2 will validate the utility of dynamic SPECT/CT imaging for quantifying serial changes in absolute skeletal muscle perfusion in a large animal model of peripheral artery occlusion. Finally, Aim 3 will translate dynamic SPECT/CT imaging into patients to evaluate the repeatability of this approach and to assess the value of absolute quantitative perfusion in 3D angiosomes in DM patients undergoing revascularization. We believe that radiotracer-based imaging will allow for high sensitivity detection of impaired foot tissue perfusion under resting conditions at baseline and following revascularization. Therefore, this imaging approach may help to identify patients at risk for wound progression or limb loss and assist in predicting treatment outcomes in PVD patients.