Reduction of Poisson noise in measured time-resolved data for time-domain diffuse optical tomography
Reduction of Poisson noise in measured time-resolved data for time-domain diffuse optical tomography
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DOI：
10.1007/s11517-011-0774-7
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发表时间：
2011
影响因子：
3.2
通讯作者：
S. Okawa;Y. Endo;Y. Hoshi;Yukio Yamada
中科院分区：
文献类型：
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作者：
S. Okawa;Y. Endo;Y. Hoshi;Yukio Yamada
提出了一种用于时域漫反射光学层析成像(DOT)的降噪方法。通过使用最大后验估计来消除污染时间分辨光子计数数据的泊松噪声。将无噪声数据建模为马尔可夫随机过程，将测量的时间分辨数据假设为泊松分布随机变量。给出了无噪声数据出现的后验概率公式。通过最大化概率来估计无噪声数据，从而降低泊松噪声。在对时域DOT图像重建的实验中，验证了泊松去噪的性能。在仿真实验中，该方法将无噪声数据和有噪声数据之间的相对误差减小到约1/30，并对重建的DOT图像进行了平滑处理。在体模实验中，重建的吸收系数的方差降低了22%。提出的降噪方法提高了DOT图像的质量，可应用于乳腺癌筛查等领域。
A method to reduce noise for time-domain diffuse optical tomography (DOT) is proposed. Poisson noise which contaminates time-resolved photon counting data is reduced by use of maximum a posteriori estimation. The noise-free data are modeled as a Markov random process, and the measured time-resolved data are assumed as Poisson distributed random variables. The posterior probability of the occurrence of the noise-free data is formulated. By maximizing the probability, the noise-free data are estimated, and the Poisson noise is reduced as a result. The performances of the Poisson noise reduction are demonstrated in some experiments of the image reconstruction of time-domain DOT. In simulations, the proposed method reduces the relative error between the noise-free and noisy data to about one thirtieth, and the reconstructed DOT image was smoothed by the proposed noise reduction. The variance of the reconstructed absorption coefficients decreased by 22% in a phantom experiment. The quality of DOT, which can be applied to breast cancer screening etc., is improved by the proposed noise reduction.