title: New spectral-spatial imaging algorithm for full EPR spectra of multiline nitroxides and pH sensitive trityl radicals.
abstract: An algorithm is derived and demonstrated that reconstructs an EPR spectral-spatial image from projections with arbitrarily selected gradients. This approach permits imaging wide spectra without the use of the very large sweep widths and gradients that would be required for spectral-spatial imaging with filtered back projection reconstruction. Each projection is defined as the sum of contributions at the set of locations in the object. At each location gradients shift the spectra in the magnetic field domain, which is equivalent to a phase change in the Fourier-conjugate frequency domain. This permits solution of the problem in the frequency domain. The method was demonstrated for 2D images of phantoms consisting of (i) two tubes containing (14)N and (15)N nitroxide and (ii) two tubes containing a pH sensitive trityl radical at pH 7.0 and 7.2. In each case spectral slices through the image agree well with the full spectra obtained in the absence of gradient.
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, USA.
authors: Mark
authors: M
authors: Tseitlin
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, USA.
authors: Joshua R
authors: JR
authors: Biller
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, USA.
authors: Hanan
authors: H
authors: Elajaili
authors: Dorothy M. Davis Heart & Lung Research Institute and Division of Pulmonary, Allergy, Critical Care & Sleep Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA.
authors: Valery V
authors: VV
authors: Khramtsov
authors: Dorothy M. Davis Heart & Lung Research Institute and Division of Pulmonary, Allergy, Critical Care & Sleep Medicine, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA.
authors: Ilirian
authors: I
authors: Dhimitruka
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, USA. Electronic address: geaton@du.edu.
authors: Gareth R
authors: GR
authors: Eaton
authors: Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80210, USA.
authors: Sandra S
authors: SS
authors: Eaton
mesh_terms: D000465:Algorithms; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D009589:Nitrogen Oxides / Q000737:chemistry*; D019047:Phantoms, Imaging; D014320:Triphenylmethyl Compounds / Q000737:chemistry*
chemical_list: D009589:Nitrogen Oxides; D014320:Triphenylmethyl Compounds
keywords: Magnetic field gradients; Nitroxide; Rapid scan EPR; Spectral–spatial imaging; pH sensitive trityl