University of California, Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California, 92612, USA.
J Biomed Opt. 2011 Jan-Feb;16(1):011015. doi: 10.1117/1.3528628.
We present an approach for rapidly and quantitatively mapping tissue absorption and scattering spectra in a wide-field, noncontact imaging geometry by combining multifrequency spatial frequency domain imaging (SFDI) with a computed-tomography imaging spectrometer (CTIS). SFDI overcomes the need to spatially scan a source, and is based on the projection and analysis of periodic structured illumination patterns. CTIS provides a throughput advantage by simultaneously diffracting multiple spectral images onto a single CCD chip to gather spectra at every pixel of the image, thus providing spatial and spectral information in a single snapshot. The spatial-spectral data set was acquired 30 times faster than with our wavelength-scanning liquid crystal tunable filter camera, even though it is not yet optimized for speed. Here we demonstrate that the combined SFDI-CTIS is capable of rapid, multispectral imaging of tissue absorption and scattering in a noncontact, nonscanning platform. The combined system was validated for 36 wavelengths between 650-1000 nm in tissue simulating phantoms over a range of tissue-like absorption and scattering properties. The average percent error for the range of absorption coefficients (μa) was less than 10% from 650-800 nm, and less than 20% from 800-1000 nm. The average percent error in reduced scattering coefficients (μs') was less than 5% from 650-700 nm and less than 3% from 700-1000 nm. The SFDI-CTIS platform was applied to a mouse model of brain injury in order to demonstrate the utility of this approach in characterizing spatially and spectrally varying tissue optical properties.
我们提出了一种方法，通过将多频空间频域成像（SFDI）与计算层析成像光谱仪（CTIS）相结合，在宽场、非接触成像几何结构中快速定量绘制组织吸收和散射光谱。SFDI 克服了对空间扫描源的需求，它基于周期性结构照明图案的投影和分析。CTIS 通过将多个光谱图像同时衍射到单个 CCD 芯片上，以在图像的每个像素处收集光谱，从而提供空间和光谱信息，从而具有吞吐量优势，从而在单个快照中提供空间和光谱信息。与我们的波长扫描液晶可调谐滤波器相机相比，尽管它尚未针对速度进行优化，但该空间光谱数据集的采集速度要快 30 倍。在这里，我们证明了组合的 SFDI-CTIS 能够在非接触、非扫描平台上快速、多光谱成像组织的吸收和散射。在一系列类似组织的吸收和散射特性的组织模拟体模中，组合系统在 650-1000nm 范围内的 36 个波长下进行了验证。在 650-800nm 范围内，吸收系数（μa）的平均百分比误差小于 10%，在 800-1000nm 范围内，吸收系数的平均百分比误差小于 20%。在 650-700nm 范围内，散射系数（μs'）的平均百分比误差小于 5%，在 700-1000nm 范围内，散射系数的平均百分比误差小于 3%。SFDI-CTIS 平台应用于脑损伤的小鼠模型，以证明该方法在表征空间和光谱变化组织光学特性方面的实用性。
