Quantifying the influence of Bessel beams on image quality in optical coherence tomography.
Quantifying the influence of Bessel beams on image quality in optical coherence tomography.
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DOI：
10.1038/srep23483
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发表时间：
2016-03-24
影响因子：
4.6
通讯作者：
Sampson DD
中科院分区：
文献类型：
--
作者：
Curatolo A;Munro PRT;Lorenser D;Sreekumar P;Singe CC;Kennedy BF;Sampson DD
众所周知，混浊组织散射的光会随着深度的增加逐渐降低光学相干断层扫描 (OCT) 图像对比度。贝塞尔光束已被提议作为高斯光束的替代品，以对浑浊组织进行更深入的成像。然而，缺乏对混浊组织比较不同光束类型的图像质量的研究。我们提出了这样一项研究，使用数值模拟光束和由贝塞尔或高斯光束形成的实验 OCT 图像来照明具有跨越软组织典型范围的光学特性的模型。我们证明，对于给定的散射参数，无论光束类型如何，散射各向异性越高，OCT 对比度越低。当将两束光束聚焦在样品中的相同深度时，我们表明，在焦点处并且对于相同的输入功率和分辨率，使用高斯光束成像时对比度的降低较小。这表明，虽然贝塞尔光束在单次深度扫描中提供了扩展的景深，但对于低数值孔径（NA < 0.1）和典型的软组织特性（散射系数，μs = 3.7 mm−1和高散射各向异性，g > 0.95），通过高斯光束与动态相结合，可以在扩展的深度范围内获得优异的对比度（高达约40％）。 聚焦。
Light scattered by turbid tissue is known to degrade optical coherence tomography (OCT) image contrast progressively with depth. Bessel beams have been proposed as an alternative to Gaussian beams to image deeper into turbid tissue. However, studies of turbid tissue comparing the image quality for different beam types are lacking. We present such a study, using numerically simulated beams and experimental OCT images formed by Bessel or Gaussian beams illuminating phantoms with optical properties spanning a range typical of soft tissue. We demonstrate that, for a given scattering parameter, the higher the scattering anisotropy the lower the OCT contrast, regardless of the beam type. When focusing both beams at the same depth in the sample, we show that, at focus and for equal input power and resolution, imaging with the Gaussian beam suffers less reduction of contrast. This suggests that, whilst Bessel beams offer extended depth of field in a single depth scan, for low numerical aperture (NA < 0.1) and typical soft tissue properties (scattering coefficient, μs = 3.7 mm−1 and high scattering anisotropy, g > 0.95), superior contrast (by up to ~40%) may be obtained over an extended depth range by a Gaussian beam combined with dynamic focusing.