title: Determining Cardiac Fiber Orientation Using FSL and Registered Ultrasound/DTI volumes.
abstract: Accurate extraction of cardiac fiber orientation from diffusion tensor imaging is important for determining heart structure and function. However, the acquisition of magnetic resonance (MR) diffusion tensor images is costly and time consuming. By comparison, cardiac ultrasound imaging is rapid and relatively inexpensive, but it lacks the capability to directly measure fiber orientations. In order to create a detailed heart model from ultrasound data, a three-dimensional (3D) diffusion tensor imaging (DTI) with known fiber orientations can be registered to an ultrasound volume through a geometric mask. After registration, the cardiac orientations from the template DTI can be mapped to the heart using a deformable transformation field. This process depends heavily on accurate fiber orientation extraction from the DTI. In this study, we use the FMRIB Software Library (FSL) to determine cardiac fiber orientations in diffusion weighted images. For the registration between ultrasound and MRI volumes, we achieved an average Dice similarity coefficient (DSC) of 81.6±2.1%. For the estimation of fiber orientations from the proposed method, we achieved an acute angle error (AAE) of 22.7±3.1° as compared to the direct measurements from DTI. This work provides a new approach to generate cardiac fiber orientation that may be used for many cardiac applications.
authors.affiliation: Department of Nuclear and Radiological Engineering, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA.
authors.forename: James
authors.initials: J
authors.lastname: Dormer
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA.
authors.forename: Xulei
authors.initials: X
authors.lastname: Qin
authors.affiliation: Department of Pediatrics, Emory University, Atlanta, GA.
authors.forename: Ming
authors.initials: M
authors.lastname: Shen
authors.affiliation: Yerkes National Primate Research Center, Emory University, Atlanta, GA.
authors.forename: Silun
authors.initials: S
authors.lastname: Wang
authors.affiliation: Yerkes National Primate Research Center, Emory University, Atlanta, GA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Pediatrics, Emory University, Atlanta, GA.
authors.forename: Rong
authors.initials: R
authors.lastname: Jiang
authors.affiliation: Department of Pediatrics, Emory University, Atlanta, GA.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Wagner
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA; Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA.
authors.forename: Baowei
authors.initials: B
authors.lastname: Fei