title: Uniform distribution of projection data for improved reconstruction quality of 4D EPR imaging.
abstract: In continuous wave (CW) electron paramagnetic resonance imaging (EPRI), high quality of reconstruction in a limited acquisition time is a high priority. It has been shown for the case of 3D EPRI, that a uniform distribution of the projection data generally enhances reconstruction quality. In this work, we have suggested two data acquisition techniques for which the gradient orientations are more evenly distributed over the 4D acquisition space as compared to the existing methods. The first sampling technique is based on equal solid angle partitioning of 4D space, while the second technique is based on Fekete points estimation in 4D to generate a more uniform distribution of data. After acquisition, filtered backprojection (FBP) is applied to carry out the reconstruction in a single stage. The single-stage reconstruction improves the spatial resolution by eliminating the necessity of data interpolation in multi-stage reconstructions. For the proposed data distributions, the simulations and experimental results indicate a higher fidelity to the true object configuration. Using the uniform distribution, we expect about 50% reduction in the acquisition time over the traditional method of equal linear angle acquisition.
authors.affiliation: Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, 420 West 12th Avenue, Columbus, OH 43210, USA.
authors.forename: Rizwan
authors.initials: R
authors.lastname: Ahmad
authors.forename: Deepti S
authors.initials: DS
authors.lastname: Vikram
authors.forename: Bradley
authors.initials: B
authors.lastname: Clymer
authors.forename: Lee C
authors.initials: LC
authors.lastname: Potter
authors.forename: Yuanmu
authors.initials: Y
authors.lastname: Deng
authors.forename: Parthasarathy
authors.initials: P
authors.lastname: Srinivasan
authors.forename: Jay L
authors.initials: JL
authors.lastname: Zweier
authors.forename: Periannan
authors.initials: P
authors.lastname: Kuppusamy
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003627:Data Interpretation, Statistical; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005583:Fourier Analysis; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity