Rapid, reliable in vivo assays of human phosphate metabolites by nuclear magnetic resonance.

1989 ◽  
Vol 35 (3) ◽  
pp. 392-395 ◽  
Author(s):  
P A Bottomley ◽  
C J Hardy
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Fast Method ◽  
Human Volunteers ◽  
Nmr Relaxation Times ◽  
The Subject ◽  
Nuclear Magnetic

Abstract This accurate, reliable, and fast method of assaying absolute concentrations of phosphate metabolites noninvasively in living tissue, including that of humans, combines 31P nuclear magnetic resonance (NMR) spectroscopy and 1H NMR imaging. The images are used to measure the areas of metabolite-bearing tissue in selected sections through the subject, and 31P spectra are acquired from the same section, together with a concentration reference located on the periphery. Metabolite concentrations are calculated from the ratios of areas and integrated signal intensities. Apparatus and protocol are designed to eliminate corrections due to magnetic field nonuniformities and NMR relaxation times. Mean (and SD) concentrations of adenosine triphosphate (ATP), phosphocreatine, and inorganic phosphate (Pi) measured in the brains of 15 normal adult human volunteers with a 1.5-T NMR system were 3.03 (0.49), 5.18 (0.89), and 1.5 (0.7) mmol per liter of wet tissue, respectively. Acquisition times of only a few minutes should facilitate metabolic studies of patients with disorders in limbs and brain, particularly those affecting entire organs.

Research of Calibration Curves NMR Relaxation Times of Nanoparticles Gadolinium Oxide

2014 ◽  
Vol 487 ◽  
pp. 94-97
Author(s):  
Chun Lin Yang ◽  
Mei Gui Ou ◽  
Jia Zeng ◽  
Xiu Qun Yang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Gadolinium Oxide ◽  
Free Ions ◽  
Calibration Curves ◽  
Relaxation Measurements ◽  
Nmr Relaxation Times

In this paper, a method of assay based on NMR (Nuclear Magnetic Resonance) measurements was developed. A protocol for the dissolution of gadolinium oxide cores and calibration curves were established for Nanoparticles gadolinium oxide. After optimization this method was used for several applications such as checking the concentration in colloids after dialysis or controlling the concentration and the form (oxides or free ions) of lanthanides after in vivo injection. The Experiments showed the samples did not present any suspension or deposit after the dissolution treatment, The concentrations calculated from relaxation measurements are very close to the concentrations measured . According to measure relaxation times T1 and T2, we can approximately determinate the gadolinium concentration. .

Nuclear magnetic resonance imaging and spectroscopy in experimental brain edema in a rat model

1986 ◽  
Vol 64 (5) ◽  
pp. 795-802 ◽  
Author(s):  
Joshua B. Bederson ◽  
Henry M. Bartkowski ◽  
Kirkland Moon ◽  
Meredith Halks-Miller ◽  
Merry C. Nishimura ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Water Content ◽  
Cerebral Blood Volume ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Resonance Imaging ◽  
Content Type ◽  
Nmr Relaxation Times

✓ Many aspects of the use of high-resolution nuclear magnetic resonance (NMR) imaging in the examination of brain edema have not been fully explored. These include the quantitation of edema fluid, the ability to distinguish between various types of edema, and the extent to which tissue changes other than a change in water content can affect NMR relaxation times. The authors have compared NMR relaxation times obtained by both in vivo magnetic resonance imaging (MRI) and in vitro NMR spectroscopy of brain-tissue samples from young adult rats with cold lesions, fluid-percussion injury, hypoxic-ischemic injury, bacterial cerebritis, and cerebral tumor. Changes in relaxation times were compared with changes in brain water content, cerebral blood volume, and the results of histological examination. In general, both in vivo and in vitro longitudinal relaxation times (T1) and transverse relaxation times (T2) were prolonged in the injured hemispheres of all experimental groups. Water content of tissue from the injured hemispheres was increased in all groups. A linear correlation between T2 (but not T1) and water content was found. Changes in the values of T1 and T2 could be used to distinguish tumor from cold-injured tissue. Cerebral blood volume was reduced in the injured hemispheres and correlated inversely with prolongation of T1 and T2. The results of this study suggest that, in a clinical setting, prolongation of T2 is a better indicator of increased water content than prolongation of T1, yet quantitation of cerebral edema based solely upon prolongation of in vivo or in vitro T1 and T2 should be undertaken with caution.

Gated in vivo examination of cardiac metabolites with 31P nuclear magnetic resonance

1986 ◽  
Vol 251 (1) ◽  
pp. H171-H175 ◽  
Author(s):  
H. L. Kantor ◽  
R. W. Briggs ◽  
K. R. Metz ◽  
R. S. Balaban
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cardiac Cycle ◽  
Relaxation Times ◽  
Spin Lattice Relaxation ◽  
31P Nmr Spectroscopy ◽  
Canine Heart ◽  
Difference Spectra ◽  
Nuclear Magnetic

Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy was used to study the temporal aspects of metabolism of canine heart in vivo. An NMR catheter coil was passed through the jugular vein of a dog into the apex of the right ventricle, and spectra were recorded at four points in the cardiac cycle by triggering from the blood pressure trace of the animal. The 31P spin-lattice relaxation times of phosphocreatine (PC) and the gamma-, alpha-, and beta-phosphates of ATP at 1.89 Tesla are 4.4, 1.8, 1.7, and 1.6 s, respectively. The ratio of PC to ATP is 2.0. No changes in PC/ATP were noted in any of the four portions of the cardiac cycle examined, and difference spectra exhibited no observable signals, in contrast to previously reported results for glucose-perfused rat hearts. On the assumption that intracellular pH and the total creatine pool were constant, the equilibrium expression for the creatine kinase reaction was used to deduce that free ADP concentrations were invariant throughout the cardiac cycle. This is in apparent disagreement with the proposed regulatory role for ADP in heart oxidative phosphorylation.

Laboratory studies of the effect of sorbed oil on proton nuclear magnetic resonance

Geophysics ◽  
2003 ◽  
Vol 68 (3) ◽  
pp. 942-948 ◽  
Author(s):  
Traci R. Bryar ◽  
Rosemary J. Knight
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Surface Area ◽  
Pore Space ◽  
Relaxation Times ◽  
Nmr Relaxation ◽  
Proton Nuclear Magnetic Resonance ◽  
Surface Relaxivity ◽  
Saturated Sands ◽  
Nuclear Magnetic

Proton NMR (nuclear magnetic resonance) measurements were made of T1 and T2 relaxation times of water in saturated sands containing varying amounts of sorbed oil on the grain surfaces. The porosity, surface area, and grain density of the sands and the relaxation times of the extracted pore water were also determined experimentally. Sorption of oil changed the relaxation time of water in the saturated sands through changes in surface area and surface relaxivity, the parameter used to quantify the ability of the surface of the pore space to reduce NMR relaxation times. In some cases the addition of oil to the surfaces decreased the surface area, an observation that suggested the oil was coating the surface in a way to reduce surface roughness. When larger amounts of oil were added to the surface, surface area increased. The changes in surface relaxivity with the amount of sorbed oil were governed by the relaxivity of the clean, oil‐free surfaces. In the Wedron sand, with a surface relaxivity typical of naturally occurring sands, the relaxivity decreased with the addition of oil to the surface of the sand grains. In the A–A sand, a clean, pure quartz sand, the relaxivity increased from a very low value for the oil‐free sample to a higher value, interpreted to be that of the oil surface.

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

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