Forrester Kevin R, Tulip J, Leonard C, Stewart C, Bray Robert C
McCaig Centre for Joint Injury and Arthritis Research, Department of Surgery, University of Calgary, Calgary, AB T2N 4N1, Canada.
IEEE Trans Biomed Eng. 2004 Nov;51(11):2074-84. doi: 10.1109/TBME.2004.834259.
Laser Doppler imaging (LDI) has become a standard method for optical measurement of tissue perfusion, but is limited by low resolution and long measurement times. We have developed an analysis technique based on a laser speckle imaging method that generates rapid, high-resolution perfusion images. We have called it laser speckle perfusion imaging (LSPI). This paper investigates LSPI output and compares it to LDI using blood flow models designed to simulate human skin at various levels of pigmentation. Results show that LSPI parameters can be chosen such that the instrumentation exhibits a similar response to changes in red blood cell concentration (0.1%-5%, 200 microL/min) and velocity (0-800 microL/min, 1% concentration) and, given its higher resolution and quicker response time, could provide a significant advantage over LDI for some applications. Differences were observed in the LDI and LSPI response to tissue optical properties. LDI perfusion values increased with increasing tissue absorption, while LSPI perfusion values showed a slight decrease. This dependence is predictable, owing to the perfusion algorithms specific to each instrument, and, if properly compensated for, should not influence each instrument's ability to measure relative changes in tissue perfusion.
激光多普勒成像（LDI）已成为组织灌注光学测量的标准方法，但受限于低分辨率和较长的测量时间。我们基于激光散斑成像方法开发了一种分析技术，可生成快速、高分辨率的灌注图像。我们将其称为激光散斑灌注成像（LSPI）。本文使用旨在模拟不同色素沉着水平人体皮肤的血流模型，研究了LSPI输出并将其与LDI进行比较。结果表明，可以选择LSPI参数，使该仪器对红细胞浓度变化（0.1%-5%，200微升/分钟）和速度变化（0-800微升/分钟，1%浓度）表现出类似的响应，并且鉴于其更高的分辨率和更快的响应时间，在某些应用中可能比LDI具有显著优势。观察到LDI和LSPI对组织光学特性的响应存在差异。LDI灌注值随组织吸收增加而增加，而LSPI灌注值略有下降。由于每种仪器特定的灌注算法，这种依赖性是可预测的，并且如果得到适当补偿，不应影响每种仪器测量组织灌注相对变化的能力。
