Fluorine electron double resonance imaging for ¹⁹F MRI in low magnetic fields

Dynamic nuclear polarization properties of nitroxyl radicals used in Overhauser-enhanced MRI for simultaneous molecular imaging

“…Transfer of polarization from unpaired electron spins to the coupled proton spins results in the enhancement of the NMR signal in regions of the sample containing free-radical, revealing its spatial distribution in the final image. This leads to the possibility of NMR imaging at very low magnetic fields [4][5][6][13][14][15][16]. OMRI offers better sensitivity than the native MRI, and its spatial resolution is not limited by the line width of the free-radical, in contrast to the ESR imaging.…”

“…Such co-registrations require additional hardware (MR imaging facility), well-thought out as well as delicate fiducial markings and suitable software for inferring the interrelated information [12]. Recently, Overhauser magnetic resonance imaging is shown to be a viable alternative to these difficulties because of the advantage that both physiologic and anatomic information can be extracted simultaneously [4][5][6]. OMRI is based on the Overhauser effect, wherein ESR resonance of the free-radical is irradiated during the acquisition of an MR image.…”

“…Further, the use of fewer animals in biological assays with molecular imaging is highly appealing, both on ethical as well as on economical grounds. The involvement of free radicals in a range of diseases has provoked considerable interest in the development of different modalities for free radical imaging in different laboratories [4][5][6][7][8][9][10][11]. Though ESR 3 imaging has exemplified as a sensitive and decisive free radical imaging modality, for morphological information of the radicals, it is often necessary to co-register the ESR images with MR images.…”

Dynamic nuclear polarization properties of nitroxyl radical in high viscous liquid using Overhauser-enhanced Magnetic Resonance Imaging (OMRI)

“…The significant contrast-to-noise ratio obtained by this technique makes OMRI advantageous in obtaining physiological information. OMRI is a promising technique for imaging the distribution and dynamics of free radicals [12][13][14][15], which is also used to demonstrate the reduction and oxidation process of 14 N and 15 N labeled nitroxyl radicals simultaneously [16].…”

Dynamic nuclear polarization studies of redox-sensitive nitroxyl spin probes in liposomal solution

“…Stable nitroxyl radicals are receiving increased attention in electron paramagnetic resonance imaging (EPRI), magnetic resonance imaging (MRI) and Overhauser-enhanced magnetic resonance imaging (OMRI) as viable reporter of in vivo redox status [9][10][11][12][13][14][15]. Simultaneous monitoring of the spin probe in aqueous and lipid phase is necessary to arrive at the redox status in vivo [16].…”