Influence of absorption and scattering on the quantification of fluorescence diffuse optical tomography using normalized data.
Influence of absorption and scattering on the quantification of fluorescence diffuse optical tomography using normalized data.
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DOI：
10.1117/1.jbo.17.3.036013
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发表时间：
2012-03
影响因子：
3.5
通讯作者：
J. Abascal;J. Aguirre;J. Chamorro-Servent;M. Schweiger;S. Arridge;J. Ripoll;J. Vaquero;M. Desco
中科院分区：
文献类型：
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作者：
J. Abascal;J. Aguirre;J. Chamorro-Servent;M. Schweiger;S. Arridge;J. Ripoll;J. Vaquero;M. Desco
用于在近红外范围内成像荧光的重建算法通常相对于激发光归一化荧光。使用这种方法，我们研究了吸收和散射不均匀性对定量准确性的影响，当假设一个均匀的模型，并探讨了可能的重建改进，通过使用非均匀模型。为此，我们创建了几个计算机模拟体模：均匀平板体模（P1），平板体模包括散射（P2）和吸收（P3）增加2至6倍的区域，以及模拟不同肝脏和肺散射（P4）的基于atlas的小鼠体模。对于P1，具有错误光学性质的重建产生了几乎随散射系数线性增加的量化误差，而关于吸收系数它们大多可以忽略不计。这一观察结果与理论结果一致。以均匀体模的定量为参考，错误假设均匀介质时获得的相对定量误差在+41至+94%（P2）、0.1至-7%（P3）和-39至+44%（P4）范围内。使用异质模型，总体误差范围为-7%至7%。总之，这项工作表明，假设均匀介质会导致明显的量化误差，可以通过采用异构模型来改善。
Reconstruction algorithms for imaging fluorescence in near infrared ranges usually normalize fluorescence light with respect to excitation light. Using this approach, we investigated the influence of absorption and scattering heterogeneities on quantification accuracy when assuming a homogeneous model and explored possible reconstruction improvements by using a heterogeneous model. To do so, we created several computer-simulated phantoms: a homogeneous slab phantom (P1), slab phantoms including a region with a two- to six-fold increase in scattering (P2) and in absorption (P3), and an atlas-based mouse phantom that modeled different liver and lung scattering (P4). For P1, reconstruction with the wrong optical properties yielded quantification errors that increased almost linearly with the scattering coefficient while they were mostly negligible regarding the absorption coefficient. This observation agreed with the theoretical results. Taking the quantification of a homogeneous phantom as a reference, relative quantification errors obtained when wrongly assuming homogeneous media were in the range +41 to +94% (P2), 0.1 to -7% (P3), and -39 to +44% (P4). Using a heterogeneous model, the overall error ranged from -7 to 7%. In conclusion, this work demonstrates that assuming homogeneous media leads to noticeable quantification errors that can be improved by adopting heterogeneous models.