Effects of wavelength-dependent fluence attenuation on the noninvasive photoacoustic imaging of hemoglobin oxygen saturation in subcutaneous vasculature in vivo
Effects of wavelength-dependent fluence attenuation on the noninvasive photoacoustic imaging of hemoglobin oxygen saturation in subcutaneous vasculature in vivo
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DOI：
10.1088/0266-5611/23/6/s09
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发表时间：
2007-12-01
期刊：
影响因子：
2.1
通讯作者：
Wang, Lihong V.
中科院分区：
文献类型：
--
作者：
Maslov, Konstantin;Zhang, Hao F.;Wang, Lihong V.
在体内血管中血红蛋白的氧饱和度（sO（2））的定量测量在光声成像中提出了挑战。由于皮肤中波长相关的光学衰减，皮下血管处的局部注量随着光谱测量中的光波长而变化，因此需要进行补偿，以便可以恢复固有吸收系数。在这里，通过采用简化的双层皮肤模型，我们证明，尽管血管中sO（2）的绝对值受到血液体积分数和真皮中空间平均sO（2）的严重影响，但相邻血管之间sO（2）的差异受到的影响最小。在实验上，我们获得补偿因子的波长相关的光衰减通过测量PA光谱皮下插入25 μ m厚的黑色薄膜，使用我们的PA显微镜。我们在体内证明，在光谱补偿之前和之后，典型动脉和典型静脉之间的sO（2）的差异是保守的。无论动物的全身生理状态如何，这种保守性都成立。
Quantitative measurements of the oxygen saturation of hemoglobin (sO(2)) in a blood vessel in vivo presents a challenge in photoacoustic imaging. As a result of wavelength-dependent optical attenuation in the skin, the local fluence at a subcutaneous vessel varies with the optical wavelength in spectral measurement and hence needs to be compensated for so that the intrinsic absorption coefficient can be recovered. Here, by employing a simplified double-layer skin model, we demonstrate that although the absolute value of sO(2) in a vessel is seriously affected by the volume fraction of blood and the spatially averaged sO(2) in the dermis, the difference of sO(2) between neighboring vessels is minimally affected. Experimentally, we acquire compensational factors for the wavelength-dependent optical attenuation by measuring the PA spectrum of a subcutaneously inserted 25 mu m thick black film using our PA microscope. We demonstrate in vivo that the difference in sO(2) between a typical artery and a typical vein is conserved before and after spectral compensation. This conservation holds regardless of the animal's systemic physiological state.