title: Enhanced Cortical Thickness Measurements for Rodent Brains via Lagrangian-based RK4 Streamline Computation.
abstract: The cortical thickness of the mammalian brain is an important morphological characteristic that can be used to investigate and observe the brain's developmental changes that might be caused by biologically toxic substances such as ethanol or cocaine. Although various cortical thickness analysis methods have been proposed that are applicable for human brain and have developed into well-validated open-source software packages, cortical thickness analysis methods for rodent brains have not yet become as robust and accurate as those designed for human brains. Based on a previously proposed cortical thickness measurement pipeline for rodent brain analysis,1we present an enhanced cortical thickness pipeline in terms of accuracy and anatomical consistency. First, we propose a Lagrangian-based computational approach in the thickness measurement step in order to minimize local truncation error using the fourth-order Runge-Kutta method. Second, by constructing a line object for each streamline of the thickness measurement, we can visualize the way the thickness is measured and achieve sub-voxel accuracy by performing geometric post-processing. Last, with emphasis on the importance of an anatomically consistent partial differential equation (PDE) boundary map, we propose an automatic PDE boundary map generation algorithm that is specific to rodent brain anatomy, which does not require manual labeling. The results show that the proposed cortical thickness pipeline can produce statistically significant regions that are not observed in the the previous cortical thickness analysis pipeline.
authors.affiliation: University of North Carolina at Chapel Hill, Department of Computer Science, United States.
authors.forename: Joohwi
authors.initials: J
authors.lastname: Lee
authors.affiliation: University of North Carolina at Chapel Hill, Department of Psychiatry, United States.
authors.forename: Sun Hyung
authors.initials: SH
authors.lastname: Kim
authors.affiliation: The University of Iowa, Department of Electrical and Computer Engineering, United States.
authors.forename: Ipek
authors.initials: I
authors.lastname: Oguz
authors.affiliation: University of North Carolina at Chapel Hill, Department of Computer Science, United States; University of North Carolina at Chapel Hill, Department of Psychiatry, United States.
authors.forename: Martin
authors.initials: M
authors.lastname: Styner
keywords: Laplace partial differential equation; cortical thickness; rodent brain analysis; runge-kutta integration