Systematic approach to cutoff frequency selection in continuous-wave electron paramagnetic resonance imaging.

This article describes a systematic method for determining the cutoff frequency of the low-pass window function that is used for deconvolution in two-dimensional continuous-wave electron paramagnetic resonance (EPR) imaging. An evaluation function for the criterion used to select the cutoff frequency is proposed, and is the product of the effective width of the point spread function for a localized point signal and the noise amplitude of a resultant EPR image. The present method was applied to EPR imaging for a phantom, and the result of cutoff frequency selection was compared with that based on a previously reported method for the same projection data set. The evaluation function has a global minimum point that gives the appropriate cutoff frequency. Images with reasonably good resolution and noise suppression can be obtained from projections with an automatically selected cutoff frequency based on the present method.

[1]  Yuanmu Deng,et al.  Fast EPR imaging at 300 MHz using spinning magnetic field gradients. , 2004, Journal of magnetic resonance.

[2]  J. Freed,et al.  Pulsed three-dimensional electron spin resonance microscopy , 2004 .

[3]  Three-dimensional pulsed ESR Fourier imaging. , 2000, Journal of magnetic resonance.

[4]  I Bajla,et al.  A high-speed reconstruction from projections using direct Fourier method with optimized parameters-an experimental analysis. , 1990, IEEE transactions on medical imaging.

[5]  J. Berliner,et al.  Magnetic resonance imaging of biological specimens by electron paramagnetic resonance of nitroxide spin labels. , 1985, Science.

[6]  Antonello Sotgiu,et al.  Limits of deconvolution in enhancing the resolution in EPR imaging experiments , 1993 .

[7]  S. Eaton,et al.  EPR imaging using flip-angle gradients: a new approach to two-dimensional imaging , 1986 .

[8]  Martyna Elas,et al.  Quantitative tumor oxymetric images from 4D electron paramagnetic resonance imaging (EPRI): Methodology and comparison with blood oxygen level‐dependent (BOLD) MRI , 2003, Magnetic resonance in medicine.

[9]  Martyn C. R. Symons,et al.  A radiofrequency ESR spectrometer for in vivo imaging , 1991 .

[10]  Hiroshi Hirata,et al.  Stability analysis and design of automatic frequency control system for in vivo EPR spectroscopy , 2001, Magnetic resonance in medicine.

[11]  Zhi-wei Luo,et al.  Control characteristics of an automatic matching control system for in vivo EPR spectroscopy , 2003, Magnetic resonance in medicine.

[12]  First imaging results obtained with a multimodal apparatus combining low-field (35.7 mT) MRI and pulsed EPRI. , 2002, Physics in medicine and biology.

[13]  R. Hingorani,et al.  Direct Fourier reconstruction in computer tomography , 1981 .

[14]  J. Hyde,et al.  The loop-gap resonator: a new microwave lumped circuit ESR sample structure , 1982 .

[15]  Paul C. Lauterbur,et al.  Principles of magnetic resonance imaging : a signal processing perspective , 1999 .

[16]  Howard J. Halpern,et al.  Imaging radio frequency electron‐spin‐resonance spectrometer with high resolution and sensitivity for in vivo measurements , 1989 .

[17]  James B. Mitchell,et al.  300 MHz continuous wave electron paramagnetic resonance spectrometer for small animal in vivo imaging , 2000 .

[18]  L. Whitehead,et al.  Split-ring resonator for use in magnetic resonance from 200-2000 MHz , 1981 .

[19]  George A. Rinard,et al.  A pulsed and continuous wave 250 MHz electron paramagnetic resonance spectrometer , 2002 .

[20]  A. Sotgiu,et al.  RAPID COMMUNICATION: Low-frequency three-dimensional ESR imaging of large samples , 1988 .

[21]  James B. Mitchell,et al.  Application of continuous‐wave EPR spectral‐spatial image reconstruction techniques for in vivo oxymetry: Comparison of projection reconstruction and constant‐time modalities , 2003, Magnetic resonance in medicine.

[22]  G Placidi,et al.  Fourier reconstruction as a valid alternative to filtered back projection in iterative applications: implementation of Fourier spectral spatial EPR imaging. , 1998, Journal of magnetic resonance.

[23]  J. Zweier,et al.  Cardiac applications of EPR imaging , 2004, NMR in biomedicine.

[24]  R. Hingorani,et al.  An Investigation of Computerized Tomography by Direct Fourier Inversion and Optimum Interpolation , 1981 .

[25]  J. Zweier,et al.  Development and optimization of three-dimensional spatial EPR imaging for biological organs and tissues. , 1995, Journal of magnetic resonance. Series B.

[26]  Harold M. Swartz,et al.  L-band electron paramagnetic resonance spectrometer for use in vivo and in studies of aqueous biological samples , 2005 .

[27]  J. Zweier,et al.  Deconvolution algorithm based on automatic cutoff frequency selection for EPR imaging , 2003, Magnetic resonance in medicine.

[28]  H. Swartz,et al.  Electronically tunable surface-coil-type resonator for L-band EPR spectroscopy. , 2000, Journal of magnetic resonance.

[29]  Andrew G. Taube,et al.  Single‐point (constant‐time) imaging in radiofrequency Fourier transform electron paramagnetic resonance † , 2002, Magnetic resonance in medicine.