Microcirculatory function in diabetic foot muscles with MRI

 描述(申请人提供)：足部溃疡是糖尿病的重要并发症，通常发生在截肢前。周围血管疾病和/或糖尿病引起的组织灌注量不足可能是导致溃疡形成和限制愈合的最重要因素。然而，从历史上看，要想 准确评估腿部和足部远端的血流灌注。我们最近展示了一种基于磁共振成像(MRI)的新方法来量化骨骼肌微循环，特别是骨骼肌血流量和氧提取分数分布。这项研究的目的是翻译这些技术来表征糖尿病患者组的小腿和足部肌肉的骨骼肌微循环。 而且没有溃疡。长期目标是在糖尿病患者进行肢体保护的介入治疗之前，将促进微循环作为主要的评估目标。将解决两个具体目标。具体目标1将确定糖尿病患者的局部血流量、氧摄取分数和足底溃疡的存在之间的关系，无论是否有外周血管病变。具体目标2将确定手术前和手术后骨骼肌血流量和氧气提取分数的措施与糖尿病周围血管疾病患者血管手术后伤口愈合的关系。所有研究都将在休息和受控运动期间进行。据推测，糖尿病、外周血管疾病和足底溃疡患者在运动过程中骨骼肌血流量和足底肌肉氧摄取分数的增加实质上是减弱的。而这种衰减 与患者血运重建后足部溃疡愈合呈负相关。完成度 这项研究将为进一步详细了解局部伤口灌流的作用提供基础，这对于制定足部溃疡患者的管理计划和建立预后至关重要。

 DESCRIPTION (provided by applicant): Foot ulcers are an important complication of diabetes mellitus and often precede lower- extremity amputation. Insufficient perfusion, due to peripheral vascular disease and/or diabetes, of the tissues may be the most important component contributing to ulcer formation and limiting healing. However, it is historically very difficult to assess distal leg and foot perfusion accurately. We recently demonstrated a novel, non-contrast, magnetic resonance imaging (MRI)-based approach to quantify skeletal muscle microcirculation, specifically skeletal muscle blood flow and oxygen extraction fraction distributions. The objective of this study is to translate these techniques to characterize the skeletal muscle microcirculation in calf and foot muscles in groups of patients with diabetes, with and without ulcers. The long term goal is to promote microcirculation as a prime evaluation target before embarking on interventional treatment for limb preservation in patients with diabetes. Two specific aims will be addressed. Specific Aim 1 will determine the relationships between regional blood flow, oxygen extraction fraction, and the presence of pedal ulcers in patients with diabetes, with and without peripheral vascular disease. Specific Aim 2 will determine how pre-surgical and post-surgical measures of skeletal muscle blood flow and oxygen extraction fraction are related to wound healing following vascular surgery in patients with DM who also have peripheral vascular disease. All study will be performed at rest and during a controlled exercise. It is hypothesized that increases in skeletal muscle blood flow and oxygen extraction fraction in plantar muscles during exercise is substantially attenuated in patients with diabetes, peripheral vascular disease, and a plantar foot ulcer. And this attenuation is inversely correlated with foot ulcer healing in patients' post-revascularization. The completion of this study will provide a foundation for further detailed understanding of role of the local wound perfusion, which is essential to developing a management plan and establishing prognosis for patients with a foot ulcer.