METHODS: Nine sections of intestine in three swine were devascularized. Pairs of indocyanine green fluorescence imaging and laser speckle contrast imaging video were quantified within perfused, watershed, and ischemic regions. Q-ICG used normalized peak inflow slope. Q-LSCI methods were laser speckle perfusion units (LSPU), the base unit of laser speckle imaging, relative perfusion units (RPU), a previously described methodology which utilizes an internal control, and zero-lag normalized cross-correlation (X-Corr), to investigate if the signal deviations convey accurate perfusion information. We determine the ability to distinguish ischemic regions and correlation to Q-ICG over a perfusion gradient.
RESULTS: All modalities distinguished ischemic from perfused regions of interest; Q-ICG values of 0.028 and 0.155 (p < 0.001); RPU values of 0.15 and 0.68 (p < 0.001); and X-corr values of 0.73 and 0.24 (p < 0.001). Over a range of perfusion levels, RPU had the best correlation with Q-ICG (r = 0.79, p < 0.001) compared with LSPU (r = 0.74, p < 0.001) and X-Corr (r = 0.46, p < 0.001).
CONCLUSIONS: These results demonstrate that Q-LSCI discriminates ischemic from perfused tissue and represents similar perfusion information over a broad range of perfusion levels comparable to clinically validated Q-ICG. This suggests that Q-LSCI might offer clinically predictive real-time dye-free quantification of tissue perfusion. Further work should include validation in histologic studies and human clinical trials.
方法:对三只猪的9个肠道进行断流处理。对吲哚菁绿荧光成像和激光散斑对比成像视频进行了量化,分水岭,和缺血区域。Q-ICG使用归一化的峰值流入斜率。Q-LSCI方法是激光散斑灌注单位(LSPU),激光散斑成像的基本单元,相对灌注单位(RPU),先前描述的利用内部控制的方法,和零滞后归一化互相关(X-Corr),以调查信号偏差是否传达准确的灌注信息。我们确定在灌注梯度上区分缺血区域和与Q-ICG的相关性的能力。
结果:所有模式区分缺血和灌注感兴趣区域;Q-ICG值为0.028和0.155(p<0.001);RPU值为0.15和0.68(p<0.001);X-corr值为0.73和0.24(p<0.001)。在一系列灌注水平上,与LSPU(r=0.74,p<0.001)和X-Corr(r=0.46,p<0.001)相比,RPU与Q-ICG(r=0.79,p<0.001)的相关性最好。
结论:这些结果表明,Q-LSCI可区分缺血与灌注组织,并在与临床验证的Q-ICG相当的广泛灌注水平上表现出相似的灌注信息。这表明Q-LSCI可以提供临床预测的组织灌注的实时无染料定量。进一步的工作应包括组织学研究和人体临床试验的验证。