Two-dimensional EPR imaging with the rapid scan and rotated magnetic field gradient

Czechowski, Tomasz; Chlewicki, Wojciech; Baranowski, Mikołaj; Jurga, K.; Szczepanik, Piotr; Szulc, Piotr; Tadyszak, Krzysztof; Kędzia, Piotr; Szostak, Marek; Malinowski, Paweł; Wosiński, Stanisław; Prukała, Wiesław; Jurga, J.

doi:10.1016/j.jmr.2014.09.022

Cited by 11 publications

(16 citation statements)

References 25 publications

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“…Therefore, major efforts were devoted to accelerate the EPR image acquisition. On par with key advances in pulsed EPR imaging, 3,10,29 Overhauser effect-based MRI, 13,[30][31][32] and development of rapid scan approaches, 4,8,33,34 traditional CW with field modulation and phase-sensitive detection has undergone major improvements. Pulsed EPR image modality allows functional (oxygen map) images of legs of living mice with matrices of 31 × 31 pixels and submillimeter resolution to be obtained in 264 seconds, 3 or for 3D imaging in vivo, the scan time is under 10 minutes and resolution is 1.4 mm to 2 mm.…”

Section: Discussionmentioning

confidence: 99%

“…Electron paramagnetic resonance–related imaging techniques that are capable of detecting paramagnetic substances in vivo have been developed and continue to be improved. These include methods that enable direct detection of paramagnetic compounds such as continuous wave (CW) EPR, time domain pulsed EPR and rapid scan EPR, as well as MRI‐based indirect techniques such as T 1 contrast imaging, which visualize a radical‐induced enhancement, and EPR/proton MRI hybrid methods that enable visualization of radical‐induced Overhauser enhancement …”

Section: Introductionmentioning

confidence: 99%

“…and continue to be improved. These include methods that enable direct detection of paramagnetic compounds such as continuous wave (CW) EPR, 1,7 time domain pulsed EPR 3 and rapid scan EPR, 4,8 as well as MRI-based indirect techniques such as T 1 contrast imaging, 9,10 which visualize a radicalinduced enhancement, and EPR/proton MRI hybrid methods that enable visualization of radical-induced Overhauser enhancement. [11][12][13] In vivo or ex vivo CW EPR imaging (EPRI) has been established as a powerful technique for determining the spatial distribution of free radicals and other paramagnetic species in living organs and tissues.…”

Section: Introductionmentioning

confidence: 99%

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Development of a fast‐scan EPR imaging system for highly accelerated free radical imaging

Samouilov

Ahmad

Boslett

et al. 2019

Magnetic Resonance in Med

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Purpose In continuous wave EPR imaging, the acquisition of high‐quality images was previously limited by the requisite long acquisition times of each image projection that was typically greater than 1 second. To accelerate the process of image acquisition facilitating greater numbers of projections and higher image resolution, instrumentation was developed to greatly accelerate the magnetic field scan that is used to obtain each EPR image projection. Methods A low‐inductance solenoidal coil for field scanning was used along with a spherical solenoid air core magnet, and scans were driven by triangular symmetric waves, allowing forward and reverse spectrum acquisition as rapid as 3.8 ms. The uniform distribution of projections was used to optimize the contribution of projections for 3D image reconstruction. Results Using this fast‐scan EPR system, high‐quality EPR images of phantoms and perfused rat hearts were performed using trityl or nanoparticulate LiNcBuO (lithium octa‐n‐butoxy‐substituted naphthalocyanine) probes with fast‐scan EPR imaging at L‐band, achieving spatial resolutions of up to 250 micrometers in 1 minute. Conclusion Fast‐scan EPR imaging can greatly facilitate the efficient and precise mapping of the spatial distribution of free radical and other paramagnetic probes in living systems.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Development of a fast‐scan EPR imaging system for highly accelerated free radical imaging

Samouilov

Ahmad

Boslett

et al. 2019

Magnetic Resonance in Med

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“…The data points were shuffled to generate projections for creation of 2D spatial images by filtered back projection. Czechowski and colleagues have demonstrated rapid-scan EPR imaging at 280 MHz for phantoms composed of two samples of LiPc with different linewidths [56, 57]. To generate a spectral-spatial image the magnetic field gradients varied slowly such that it was approximately constant during the time required for a full 2 kHz sinusoidal scan [56].…”

Section: Application To Low-frequency Epr Imagingmentioning

confidence: 99%

“…Seven iterations of the Ordered Subset Expectation Maximization method were used to create images with 1.0 cm by 0.5 G dimensions. Projections for a spatial-spatial image were acquired with 4 kHz sinusoidal scans and the magnetic field gradient varied at a rate of 100 Hz [57]. For a sample with ~ 10 17 spins/tube the time for a 2D image was about 20 ms. For samples with fewer spins, signal averaging would be required, which would increase the imaging time.…”

Section: Application To Low-frequency Epr Imagingmentioning

confidence: 99%

Rapid-scan EPR imaging

Eaton

Shi

Woodcock

et al. 2017

Journal of Magnetic Resonance

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In rapid-scan EPR the magnetic field or frequency is repeatedly scanned through the spectrum at rates that are much faster than in conventional continuous wave EPR. The signal is directly-detected with a mixer at the source frequency. Rapid-scan EPR is particularly advantageous when the scan rate through resonance is fast relative to electron spin relaxation rates. In such scans, there may be oscillations on the trailing edge of the spectrum. These oscillations can be removed by mathematical deconvolution to recover the slow-scan absorption spectrum. In cases of inhomogeneous broadening, the oscillations may interfere destructively to the extent that they are not visible. The deconvolution can be used even when it is not required, so spectra can be obtained in which some portions of the spectrum are in the rapid-scan regime and some are not. The technology developed for rapid-scan EPR can be applied generally so long as spectra are obtained in the linear response region. The detection of the full spectrum in each scan, the ability to use higher microwave power without saturation, and the noise filtering inherent in coherent averaging results in substantial improvement in signal-to-noise relative to conventional continuous wave spectroscopy, which is particularly advantageous for low-frequency EPR imaging. This overview describes the principles of rapid-scan EPR and the hardware used to generate the spectra. Examples are provided of its application to imaging of nitroxide radicals, diradicals, and spin-trapped radicals at a Larmor frequency of ca. 250 MHz.

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Merging Preclinical EPR Tomography with other Imaging Techniques

Gonet

Epel

Halpern

et al. 2019

Cell Biochem Biophys

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This paper presents a survey of electron paramagnetic resonance (EPR) image registration. Image registration is the process of overlaying images (two or more) of the same scene taken at different times, from different viewpoints and/or different techniques. EPR-imaging (EPRI) techniques belong to the functional-imaging modalities and therefore suffer from a lack of anatomical reference which is mandatory in preclinical imaging. For this reason, it is necessary to merging EPR images with other modalities which allow for obtaining anatomy images. Methodological analysis and review of the literature were done, providing a summary for developing a good foundation for research study in this field which is crucial in understanding the existing levels of knowledge. Out of these considerations, the aim of this paper is to enhance the scientific community’s understanding of the current status of research in EPR preclinical image registration and also communicate to them the contribution of this research in the field of image processing.

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Two-dimensional EPR imaging with the rapid scan and rotated magnetic field gradient

Cited by 11 publications

References 25 publications

Development of a fast‐scan EPR imaging system for highly accelerated free radical imaging

Development of a fast‐scan EPR imaging system for highly accelerated free radical imaging

Rapid-scan EPR imaging

Merging Preclinical EPR Tomography with other Imaging Techniques

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