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2 results on '"Schepkin VD"'

1. Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale.

Author

Budinger TF, Bird MD, Frydman L, Long JR, Mareci TH, Rooney WD, Rosen B, Schenck JF, Schepkin VD, Sherry AD, Sodickson DK, Springer CS, Thulborn KR, Uğurbil K, and Wald LL

Subjects
Anisotropy, Axons pathology, Brain pathology, Brain Mapping methods, Computer Simulation, Energy Metabolism, Glucose analysis, Hot Temperature, Humans, Motion, Neurons pathology, Permeability, Reproducibility of Results, Sodium-Potassium-Exchanging ATPase chemistry, Spectrophotometry, Whole Body Imaging, Brain diagnostic imaging, Magnetic Resonance Imaging
Abstract

An initiative to design and build magnetic resonance imaging (MRI) and spectroscopy (MRS) instruments at 14 T and beyond to 20 T has been underway since 2012. This initiative has been supported by 22 interested participants from the USA and Europe, of which 15 are authors of this review. Advances in high temperature superconductor materials, advances in cryocooling engineering, prospects for non-persistent mode stable magnets, and experiences gained from large-bore, high-field magnet engineering for the nuclear fusion endeavors support the feasibility of a human brain MRI and MRS system with 1 ppm homogeneity over at least a 16-cm diameter volume and a bore size of 68 cm. Twelve neuroscience opportunities are presented as well as an analysis of the biophysical and physiological effects to be investigated before exposing human subjects to the high fields of 14 T and beyond.

Published
2016
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2. In vivo chlorine and sodium MRI of rat brain at 21.1 T.

Author

Schepkin VD, Elumalai M, Kitchen JA, Qian C, Gor'kov PL, and Brey WW

Subjects
Animals, Disease Progression, Equipment Design, Imaging, Three-Dimensional, Rats, Brain Neoplasms pathology, Chlorine chemistry, Glioma pathology, Magnetic Resonance Imaging methods, Sodium chemistry
Abstract

Object: MR imaging of low-gamma nuclei at the ultrahigh magnetic field of 21.1 T provides a new opportunity for understanding a variety of biological processes. Among these, chlorine and sodium are attracting attention for their involvement in brain function and cancer development., Materials and Methods: MRI of (35)Cl and (23)Na were performed and relaxation times were measured in vivo in normal rat (n = 3) and in rat with glioma (n = 3) at 21.1 T. The concentrations of both nuclei were evaluated using the center-out back-projection method., Results: T 1 relaxation curve of chlorine in normal rat head was fitted by bi-exponential function (T 1a = 4.8 ms (0.7) T 1b = 24.4 ± 7 ms (0.3) and compared with sodium (T 1 = 41.4 ms). Free induction decays (FID) of chlorine and sodium in vivo were bi-exponential with similar rapidly decaying components of [Formula: see text] ms and [Formula: see text] ms, respectively. Effects of small acquisition matrix and bi-exponential FIDs were assessed for quantification of chlorine (33.2 mM) and sodium (44.4 mM) in rat brain., Conclusion: The study modeled a dramatic effect of the bi-exponential decay on MRI results. The revealed increased chlorine concentration in glioma (~1.5 times) relative to a normal brain correlates with the hypothesis asserting the importance of chlorine for tumor progression.

Published
2014
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