In vivo imaging of a stable paramagnetic probe by pulsed-radiofrequency electron paramagnetic resonance spectroscopy

Murugesan, Ramachandran ; Cook, John A. ; Devasahayam, Nallathamby ; Afeworki, Mobae ; Subramanian, Sankaran ; Tschudin, Rolf ; Larsen, Janhenrik A. ; Mitchell, James B. ; Russo, Angelo ; Krishna, Murali C. (1997) In vivo imaging of a stable paramagnetic probe by pulsed-radiofrequency electron paramagnetic resonance spectroscopy Magnetic Resonance in Medicine, 38 (3). pp. 409-414. ISSN 0740-3194

Full text not available from this repository.

Official URL:

Related URL:


Imaging of free radicals by electron paramagnetic resonance (EPR) spectroscopy using time domain acquisition as in nuclear magnetic resonance (NMR) has not been attempted because of the short spin-spin relaxation times, typically under 1 μs, of most biologically relevant paramagnetic species. Recent advances in radiofrequency (RF) electronics have enabled the generation of pulses of the order of 10-50 ns. Such short pulses provide adequate spectral coverage for EPR studies at 300 MHz resonant frequency. Acquisition of free induction decays (FID) of paramagnetic species possessing inhomogenously broadened narrow lines after pulsed excitation is feasible with an appropriate digitizer/averager. This report describes the use of time-domain RF EPR spectrometry and imaging for in vivo applications. FID responses were collected from a water-soluble, narrow line width spin probe within phantom samples in solution and also when infused intravenously in an anesthetized mouse. Using static magnetic field gradients and back-projection methods of image reconstruction, two-dimensional images of the spin-probe distribution were obtained in phantom samples as well as in a mouse. The resolution in the images was better than 0.7 mm and devoid of motional artifacts in the in vivo study. Results from this study suggest a potential use for pulsed RF EPR imaging (EPRI) for three-dimensional spatial and spectral-spatial imaging applications. In particular, pulsed EPRI may find use in in vivo studies to minimize motional artifacts from cardiac and lung motion that cause significant problems in frequency-domain spectral acquisition, such as in continuous wave (cw) EPR techniques.

Item Type:Article
Source:Copyright of this article belongs to John Wiley and Sons.
Keywords:Pulsed EPR; EPR Imaging; In Vivo EPR; Free Radical
ID Code:51925
Deposited On:01 Aug 2011 07:30
Last Modified:01 Aug 2011 07:30

Repository Staff Only: item control page