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.
Samouilov
Alexandre
A
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Caia
George L
GL
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Kesselring
Eric
E
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Petryakov
Sergey
S
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Wasowicz
Tomasz
T
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
Zweier
Jay L
JL
Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
D000818:Animals; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D019047:Phantoms, Imaging