Mapping the Spin-Density and Lineshape Distribution of Free Radicals Using 4D Spectral-Spatial EPR Imaging

Kuppusamy, Periannan; Chzhan, Michael; Samouilov, Alexandre; Wang, Penghai; Zweíer, Jay L.

doi:10.1006/jmrb.1995.1067

Cited by 75 publications

(75 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Four-dimensional EPRI, however, places severe constraints on the design and power of field gradients, data acquisition time, and sensitivity of the probe. 21 …”

Section: Nmr Vs Epr Imagingmentioning

confidence: 99%

“…We have demonstrated that high quality and high-resolution 4D spectralspatial images of biological organs and tissues of sizes up to 25 mm diameter can be obtained. 21 A variety of free radical labels, including nitroxyls, and dispersions of solid-state probes have been evaluated as potential probes for EPR oximetry and metabolic studies. The feasibility of studying small linewidth differences of less than 0.1 G in samples of up to 25 mm in size has been demonstrated.…”

Section: D Mapping Of Myocardial Oxygenation In the Ischemic Heartmentioning

confidence: 99%

“…The feasibility of studying small linewidth differences of less than 0.1 G in samples of up to 25 mm in size has been demonstrated. 21 To evaluate the ability of EPR imaging to resolve more detailed anatomical structure within the heart, we infused a stable colloidal aqueous suspension of the glucose char oximetry label 59 and imaged the isolated, globally ischemic rat heart (Plate 3). The glucose char material is highly oxygen sensitive with a linewidth of 0.19 G in the absence of oxygen and more than 100 G in air.…”

Section: D Mapping Of Myocardial Oxygenation In the Ischemic Heartmentioning

confidence: 99%

“…[9][10][11][12][13][14][15][16][17][18] Over the last decade we have focused on developing instrumentation optimized for measurements of free radicals in isolated beating hearts, and in recent several years we have extended our efforts to develop hardware and software to enable spatial and spectral-spatial imaging of free radicals in the heart. 9,[19][20][21][22][23][24][25] This review provides a summary of the development and application of the imaging techniques with examples including imaging of stable free radical labels, oxygen concentrations and nitric oxide generation in the normal or ischemic heart.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Cardiac applications of EPR imaging

Kuppusamy

Zweíer

2004

NMR in Biomedicine

View full text Add to dashboard Cite

This review summarizes the development and application of a variety of EPR imaging modalities including spatial, spectral-spatial (spectroscopic), gated-imaging and oxygen mapping to cardiovascular studies. It has been hypothesized that free radical metabolism, oxygenation and nitric oxide generation in biological organs such as the heart may vary over the spatially defined tissue structure. We have developed instrumentation optimized for 3D spatial and 3D or 4D spectral-spatial imaging of free radicals at 1.2 GHz. Using this instrumentation high quality 3D spectral-spatial imaging of nitroxyl (nitroxide) metabolism was performed, as well as spatially localized measurements of oxygen concentrations, based on the oxygen-dependent line-broadening of the EPR spectrum. Both exogenously infused probes and endogenous radicals were used to obtain the images. It is demonstrated that the EPR imaging is a powerful tool which can provide unique information regarding the spatial localization of free radicals, oxygen and nitric oxide in biological organs and tissues.

show abstract

“…Four-dimensional EPRI, however, places severe constraints on the design and power of field gradients, data acquisition time, and sensitivity of the probe. 21 …”

Section: Nmr Vs Epr Imagingmentioning

confidence: 99%

Section: D Mapping Of Myocardial Oxygenation In the Ischemic Heartmentioning

confidence: 99%

Section: D Mapping Of Myocardial Oxygenation In the Ischemic Heartmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Cardiac applications of EPR imaging

Kuppusamy

Zweíer

2004

NMR in Biomedicine

View full text Add to dashboard Cite

show abstract

“…Since the reconstruction is carried out in a single stage without the necessity of interpolation, the spatial resolution does not degrade. The computation time, however, can be longer as compared to multistage reconstruction where nD EPR image is reconstructed through (n -1) stages of 2D backprojection operations [21]. By limiting the size of the reconstructed image and by breaking the reconstruction into subsets, the processing time for 4D single-stage reconstruction can be deemed manageable.…”

Section: Introductionmentioning

confidence: 99%

Uniform distribution of projection data for improved reconstruction quality of 4D EPR imaging

Ahmad¹,

Vikram²,

Clymer³

et al. 2007

Journal of Magnetic Resonance

View full text Add to dashboard Cite

In continuous wave (CW) electron paramagnetic resonance imaging (EPRI), high quality of reconstruction in a limited acquisition time is a high priority. It has been shown for the case of 3D EPRI, that a uniform distribution of the projection data generally enhances reconstruction quality. In this work, we have suggested two data acquisition techniques for which the gradient orientations are more evenly distributed over the 4D acquisition space as compared to the existing methods. The first sampling technique is based on equal solid angle partitioning of 4D space, while the second technique is based on Fekete points estimation in 4D to generate a more uniform distribution of data. After acquisition, filtered backprojection (FBP) is applied to carryout the reconstruction in a single stage. The single-stage reconstruction improves the spatial resolution by eliminating the necessity of data interpolation in multi-stage reconstructions. For the proposed data distributions, the simulations and experimental results indicate a higher fidelity to the true object configuration. Using the uniform distribution, we expect about 50% reduction in the acquisition time over the traditional method of equal linear angle acquisition.

show abstract