Development of a hybrid EPR/NMR coimaging system.
Electron paramagnetic resonance imaging (EPRI) is a powerful technique that enables spatial mapping of free radicals or other paramagnetic compounds; however, it does not in itself provide anatomic visualization of the body. Proton magnetic resonance imaging (MRI) is well suited to provide anatomical visualization. A hybrid EPR/NMR coimaging instrument was constructed that utilizes the complementary capabilities of both techniques, superimposing EPR and proton-MR images to provide the distribution of paramagnetic species in the body. A common magnet and field gradient system is utilized along with a dual EPR and proton-NMR resonator assembly, enabling coimaging without the need to move the sample. EPRI is performed at approximately 1.2 GHz/ approximately 40 mT and proton MRI is performed at 16.18 MHz/ approximately 380 mT; hence the method is suitable for whole-body coimaging of living mice. The gradient system used is calibrated and controlled in such a manner that the spatial geometry of the two acquired images is matched, enabling their superposition without additional postprocessing or marker registration. The performance of the system was tested in a series of phantoms and in vivo applications by mapping the location of a paramagnetic probe in the gastrointestinal (GI) tract of mice. This hybrid EPR/NMR coimaging instrument enables imaging of paramagnetic molecules along with their anatomic localization in the body.
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Alexandre
A
Samouilov
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
George L
GL
Caia
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Eric
E
Kesselring
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Sergey
S
Petryakov
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Tomasz
T
Wasowicz
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Jay L
JL
Zweier
D000818:Animals; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D019047:Phantoms, Imaging