title: Performance investigation of SP3 and diffusion approximation for three-dimensional whole-body optical imaging of small animals.
abstract: The third-order simplified harmonic spherical approximation (SP3) and diffusion approximation (DA) equations have been widely used in the three-dimensional (3D) whole-body optical imaging of small animals. With different types of tissues, which were classified by the ratio of µ s'/µ ɑ, the two equations have their own application scopes. However, the classification criterion was blurring and unreasonable, and the scope has not been systematically investigated until now. In this study, a new criterion for classifying tissues was established based on the absolute value of absorption and reduced scattering coefficients. Using the newly defined classification criterion, the performance and applicability of the SP3 and DA equations were evaluated with a series of investigation experiments. Extensive investigation results showed that the SP3 equation exhibited a better performance and wider applicability than the DA one in most of the observed cases, especially in tissues of low-scattering-low-absorption and low-scattering-high-absorption range. For the case of tissues with the high-scattering-low-absorption properties, a similar performance was observed for both the SP3 and the DA equations, in which case the DA was the preferred option for 3D whole-body optical imaging. Results of this study would provide significant reference for the study of hybrid light transport models.
authors: Engineering Research Center of Molecular and Neuro Imaging of Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China.
authors: Defu
authors: D
authors: Yang
authors: Engineering Research Center of Molecular and Neuro Imaging of Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China. xuelichenmig@gmail.com.
authors: Xueli
authors: X
authors: Chen
authors: Engineering Research Center of Molecular and Neuro Imaging of Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China.
authors: Xu
authors: X
authors: Cao
authors: Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China.
authors: Jing
authors: J
authors: Wang
authors: Engineering Research Center of Molecular and Neuro Imaging of Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China.
authors: Jimin
authors: J
authors: Liang
authors: Engineering Research Center of Molecular and Neuro Imaging of Ministry of Education, School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China.|Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China.
authors: Jie
authors: J
authors: Tian
mesh_terms: D065966:Absorption, Physicochemical; D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D004058:Diffusion; D020342:Finite Element Analysis; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008027:Light; D051379:Mice; D009010:Monte Carlo Method; D061848:Optical Imaging / Q000379:methods*; D017785:Photons; D051598:Whole Body Imaging / Q000379:methods*
keywords: Diffusion approximation; Performance investigation; Third-order simplified harmonic spherical approximation; Three-dimensional optical imaging; Tissue classification criterion