Numerical Investigation of the Mechanisms of Ultrasound-Modulated Bioluminescence Tomography.
Numerical Investigation of the Mechanisms of Ultrasound-Modulated Bioluminescence Tomography.
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超声调制生物发光断层扫描机制的数值研究。
DOI：
10.1109/tbme.2015.2405415
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Zhang Q
中科院分区：
文献类型：
--
作者：
Zhang Q
目的一种混合成像技术，即超声调制发光断层扫描，利用超声调制漫传播光，已被证明可以提高光学图像的空间分辨率。本文研究了潜在的调制机制以及应用该技术提高生物发光断层扫描空间分辨率的可行性。方法对超声调制生物发光断层扫描进行数值研究，以确定四个因素（降低的光学散射系数、光学吸收系数、折射率和荧光素酶浓度）对光调制深度的影响。在实践中，对用于模拟漫传播光、近红外荧光和光谱断层扫描的开源有限元方法工具进行了修改，以纳入超声调制的影响。使用小鼠模型的光学和物理特性计算检测到的调制生物发光发射的信噪比。结果受美国引起的发光酶荧光素酶局部浓度变化影响的生物发光发射的调制深度比其他因素的变化引起的影响至少大两个数量级。对于高于大约 107photons/s/cm2/sr 的表面辐射，可以使用当前可用的检测器技术检测相应的 SNR。 结论 超声调制生物发光产生的主要影响是超声引起的荧光素酶浓度变化。信噪比分析证实了超声调制生物发光断层扫描在小鼠临床前成像中的可行性。意义开发的模拟模型表明超声调制生物发光断层扫描是提高生物发光断层扫描空间分辨率的潜在技术。
ObjectiveA hybrid imaging technique, ultrasound-modulated luminescence tomography, that uses ultrasound to modulate diffusely propagating light has been shown to improve the spatial resolution of optical images. This paper investigates the underlying modulation mechanisms and the feasibility of applying this technique to improve spatial resolution in bioluminescence tomography.MethodsUltrasound-modulated bioluminescence tomography was studied numerically to identify the effects of four factors (reduced optical scattering coefficient, optical absorption coefficient, refractive index, and luciferase concentration) on the depth of light modulation. In practice, an open source finite-element method tool for simulation of diffusely propagating light, near infrared fluorescence and spectral tomography, was modified to incorporate the effects of ultrasound modulation. The signal-to-noise ratios of detected modulated bioluminescent emissions are calculated using the optical and physical properties of a mouse model.ResultsThe modulation depth of the bioluminescent emission affected by the US induced variation of local concentration of the light emitting enzyme luciferase was at least two orders of magnitude greater than that caused by variations in the other factors. For surface radiances above approximately 107photons/s/cm2/sr, the corresponding SNRs are detectable with the currently available detector technologies.ConclusionThe dominant effect in generation of ultrasound-modulated bioluminescence is ultrasound induced variation in luciferase concentration. The SNR analysis confirms the feasibility of applying ultrasound-modulated bioluminescence tomography in preclinical imaging of mice.SignificanceThe simulation model developed suggests ultrasound-modulated bioluminescence tomography is a potential technique to improve the spatial resolution of bioluminescence tomography.