Microvascular Diagnostics, Regional Medical Physics Department, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK.
Physiol Meas. 2014 Jul;35(7):R91-R141. doi: 10.1088/0967-3334/35/7/R91. Epub 2014 Jun 9.
The microvasculature presents a particular challenge in physiological measurement because the vessel structure is spatially inhomogeneous and perfusion can exhibit high variability over time. This review describes, with a clinical focus, the wide variety of methods now available for imaging of the microvasculature and their key applications. Laser Doppler perfusion imaging and laser speckle contrast imaging are established, commercially-available techniques for determining microvascular perfusion, with proven clinical utility for applications such as burn-depth assessment. Nailfold capillaroscopy is also commercially available, with significant published literature that supports its use for detecting microangiopathy secondary to specific connective tissue diseases in patients with Raynaud's phenomenon. Infrared thermography measures skin temperature and not perfusion directly, and it has only gained acceptance for some surgical and peripheral microvascular applications. Other emerging technologies including imaging photoplethysmography, optical coherence tomography, photoacoustic tomography, hyperspectral imaging, and tissue viability imaging are also described to show their potential as techniques that could become established tools for clinical microvascular assessment. Growing interest in the microcirculation has helped drive the rapid development in perfusion imaging of the microvessels, bringing exciting opportunities in microvascular research.
微血管在生理测量中提出了一个特殊的挑战，因为血管结构在空间上是不均匀的，灌注在时间上可以表现出高度的可变性。本篇综述以临床为重点，描述了目前可用于微血管成像的各种方法及其关键应用。激光多普勒灌注成像和激光散斑对比成像作为确定微血管灌注的成熟、商业化技术，已被证明在烧伤深度评估等应用中具有临床实用性。甲襞微循环检查也是商业化的，有大量的文献支持其用于检测雷诺现象患者特定结缔组织病继发的微血管病变。近红外热成像测量的是皮肤温度而不是灌注，它仅在一些外科和周围微血管应用中被接受。其他新兴技术，包括成像光体积描记术、光学相干断层扫描、光声断层扫描、高光谱成像和组织活力成像，也被描述，以展示它们作为可能成为临床微血管评估的成熟工具的技术的潜力。对微循环的日益关注推动了微血管灌注成像的快速发展，为微血管研究带来了令人兴奋的机遇。
