Rapid near-infrared diffuse tomography for hemodynamic imaging using a low-coherence wideband light source.
Rapid near-infrared diffuse tomography for hemodynamic imaging using a low-coherence wideband light source.
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DOI：
10.1117/1.2709636
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发表时间：
2007
影响因子：
3.5
通讯作者：
D. Piao;B. Pogue
中科院分区：
文献类型：
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作者：
D. Piao;B. Pogue
采用低相干源实现了快速近红外（NIR）漫射光学层析成像。低相干光源的光谱带宽被分散并耦合到线性束束光纤上，这样在束束光纤之间形成了“扩展”光谱编码，并且可以用于平行光源照明到组织上。与以前使用多个激光二极管的频谱编码技术相比，使用低相干源进行扩频编码具有以下几个独特的特点：(1)它提供无移位的频谱编码；(2)最大限度地减少了通道间自发强度波动，显著降低了重建的不确定性；(3)使近红外层析成像实现为内窥镜成像模式。在由8个光源和8个探测通道组成的27 mm成像阵列中，采用一个以840 nm为中心、带宽为40 nm的20 mw超发光二极管作为光源，获得了5 Hz的采样速度。阐述了利用低相干源进行扩频编码的原理，论证了其特征性能，并给出了自主憋气10 s期间血红蛋白吸收变化成像的初步结果。
Rapid near-infrared (NIR) diffuse optical tomography is implemented using a low-coherence source. The spectral bandwidth of the low-coherence source is dispersed and coupled to linearly bundled fibers, such that "spread"-spectral encoding among the bundled fibers is formed, and could be used for parallel source illumination onto tissue. In comparison with a previous spectral-encoding technique that employed multiple laser diodes, the use of a low-coherence source for spread-spectral encoding presents a few unique characteristics: (1) it provides shift-free spectral encoding; (2) it reduces the reconstruction uncertainty significantly owing to the minimization of spontaneous channel-to-channel intensity fluctuation; and (3) it enables the implementation of NIR tomography into an endoscopic imaging mode. A 20-mW superluminescent diode centered at 840 nm with a 40-nm bandwidth is used as the source, and a sampling speed of 5 Hz is obtained in a 27-mm imaging array consisting of eight sources and eight detection channels. The principles of using a low-coherence source for spread-spectral encoding are elaborated, the characteristic performances are demonstrated, and the preliminary results of imaging hemoglobin absorption variations during 10 s of voluntary breath-holding are presented.