Jansen Sanne M, de Bruin Daniel M, Faber Dirk J, Dobbe Iwan J G G, Heeg Erik, Milstein Dan M J, Strackee Simon D, van Leeuwen Ton G
University of Amsterdam, Academic Medical Center, Department of Biomedical Engineering and Physics,, The Netherlands.
University of Amsterdam, Academic Medical Center, Department of Plastic, Reconstructive, and Hand Su, The Netherlands.
J Biomed Opt. 2017 Aug;22(8):1-9. doi: 10.1117/1.JBO.22.8.086004.
Patient morbidity and mortality due to hemodynamic complications are a major problem in surgery. Optical techniques can image blood flow in real-time and high-resolution, thereby enabling perfusion monitoring intraoperatively. We tested the feasibility and validity of laser speckle contrast imaging (LSCI), optical coherence tomography (OCT), and sidestream dark-field microscopy (SDF) for perfusion diagnostics in a phantom model using whole blood. Microvessels with diameters of 50, 100, and 400 μm were constructed in a scattering phantom. Perfusion was simulated by pumping heparinized human whole blood at five velocities (0 to 20 mm/s). Vessel diameter and blood flow velocity were assessed with LSCI, OCT, and SDF. Quantification of vessel diameter was feasible with OCT and SDF. LSCI could only visualize the 400-μm vessel, perfusion units scaled nonlinearly with blood velocity. OCT could assess blood flow velocity in terms of inverse OCT speckle decorrelation time. SDF was not feasible to measure blood flow; however, for diluted blood the measurements were linear with the input velocity up to 1 mm/s. LSCI, OCT, and SDF were feasible to visualize blood flow. Validated blood flow velocity measurements intraoperatively in the desired parameter (mL·min-1·g-1) remain challenging.
血流动力学并发症导致的患者发病和死亡是外科手术中的一个主要问题。光学技术可以实时、高分辨率地成像血流，从而实现术中灌注监测。我们在使用全血的体模模型中测试了激光散斑对比成像（LSCI）、光学相干断层扫描（OCT）和侧流暗视野显微镜（SDF）用于灌注诊断的可行性和有效性。在散射体模中构建了直径为50、100和400μm的微血管。通过以五种速度（0至20mm/s）泵注肝素化人全血来模拟灌注。用LSCI、OCT和SDF评估血管直径和血流速度。用OCT和SDF对血管直径进行量化是可行的。LSCI只能观察到400μm的血管，灌注单位与血流速度呈非线性比例关系。OCT可以根据逆OCT散斑去相关时间评估血流速度。SDF测量血流不可行；然而，对于稀释血液，测量值在输入速度高达1mm/s时与输入速度呈线性关系。LSCI、OCT和SDF可以观察到血流。在术中以所需参数（mL·min-1·g-1）进行经过验证的血流速度测量仍然具有挑战性。
