title: Comparison of parabolic filtration methods for 3D filtered back projection in pulsed EPR imaging.
abstract: Pulse electron paramagnetic resonance imaging (Pulse EPRI) is a robust method for noninvasively measuring local oxygen concentrations in vivo. For 3D tomographic EPRI, the most commonly used reconstruction algorithm is filtered back projection (FBP), in which the parabolic filtration process strongly influences image quality. In this work, we designed and compared 7 parabolic filtration methods to reconstruct both simulated and real phantoms. To evaluate these methods, we designed 3 error criteria and 1 spatial resolution criterion. It was determined that the 2 point derivative filtration method and the two-ramp-filter method have unavoidable negative effects resulting in diminished spatial resolution and increased artifacts respectively. For the noiseless phantom the rectangular-window parabolic filtration method and sinc-window parabolic filtration method were found to be optimal, providing high spatial resolution and small errors. In the presence of noise, the 3 point derivative method and Hamming-window parabolic filtration method resulted in the best compromise between low image noise and high spatial resolution. The 3 point derivative method is faster than Hamming-window parabolic filtration method, so we conclude that the 3 point derivative method is optimal for 3D FBP.
authors.affiliation: Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA; School of Computer and Control Engineering, North University of China, Taiyuan, Shanxi 030051, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Qiao
authors.affiliation: Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Gage
authors.initials: G
authors.lastname: Redler
authors.affiliation: Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Boris
authors.initials: B
authors.lastname: Epel
authors.affiliation: Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL 60637, USA. Electronic address: h-halpern@uchicago.edu.
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Halpern
mesh_terms: D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D010100:Oxygen
keywords: 3D FBP; EPRI; Noise; Parabolic filter; Spatial resolution