Xing, Y., et al., Optimal variable flip angle schemes for dynamic acquisition of exchanging hyperpolarized substrates. J. Magn. Reson., 2013. 234(0): p. 75-81.
In metabolic MRI with hyperpolarized contrast agents, the signal levels vary over time due to T1 decay, T2 decay following RF excitations, and metabolic conversion. Efficient usage of the nonrenewable hyperpolarized magnetization requires specialized RF pulse schemes. In this work, we introduce two novel variable flip angle schemes for dynamic hyperpolarized MRI in which the flip angle is varied between excitations and between metabolites. These were optimized to distribute the magnetization relatively evenly throughout the acquisition by accounting for T1 decay, prior RF excitations, and metabolic conversion. Simulation results are presented to confirm the flip angle designs and evaluate the variability of signal dynamics across typical ranges of T1 and metabolic conversion. They were implemented using multiband spectral-spatial RF pulses to independently modulate the flip angle at various chemical shift frequencies. With these schemes we observed increased SNR of [1-(13)C]lactate generated from [1-(13)C]pyruvate, particularly at later time points. This will allow for improved characterization of tissue perfusion and metabolic profiles in dynamic hyperpolarized MRI.
[NMR paper] Orphan spin operators enable the acquisition of multiple 2D and 3D magic angle spinning solid-state NMR spectra.
Orphan spin operators enable the acquisition of multiple 2D and 3D magic angle spinning solid-state NMR spectra.
Related Articles Orphan spin operators enable the acquisition of multiple 2D and 3D magic angle spinning solid-state NMR spectra.
J Chem Phys. 2013 May 14;138(18):184201
Authors: Gopinath T, Veglia G
Abstract
We propose a general method that enables the acquisition of multiple 2D and 3D solid-state NMR spectra for U-(13)C, (15)N-labeled proteins. This method, called MEIOSIS (Multiple ExperIments via Orphan SpIn operatorS), makes...
3D DUMAS: Simultaneous acquisition of three-dimensional magic angle spinning solid-state NMR experiments of proteins
3D DUMAS: Simultaneous acquisition of three-dimensional magic angle spinning solid-state NMR experiments of proteins
July 2012
Publication year: 2012
Source:Journal of Magnetic Resonance, Volume 220</br>
</br>
Using the DUMAS (Dual acquisition Magic Angle Spinning) solid-state NMR approach, we created new pulse schemes that enable the simultaneous acquisition of three dimensional (3D) experiments on uniformly 13C, 15N labeled proteins. These new experiments exploit the simultaneous cross-polarization (SIM-CP) from 1H to 13C and 15N to acquire two 3D experiments...
nmrlearner
Journal club
0
02-03-2013 10:13 AM
3D DUMAS: Simultaneous Acquisition of Three-Dimensional Magic Angle Spinning Solid-State NMR Experiments of Proteins
3D DUMAS: Simultaneous Acquisition of Three-Dimensional Magic Angle Spinning Solid-State NMR Experiments of Proteins
Publication year: 2012
Source:Journal of Magnetic Resonance</br>
T. Gopinath, Gianluigi Veglia</br>
Using the DUMAS (Dual acquisition Magic Angle Spinning) solid-state NMR approach, we created new pulse schemes that enable the simultaneous acquisition of three dimensional (3D) experiments on uniformly 13C, 15N labeled proteins. These new experiments exploit the simultaneous cross-polarization (SIM-CP) from 1H to 13C and 15N to acquire two 3D experiments...
nmrlearner
Journal club
0
04-26-2012 08:10 PM
Intermolecular Structure Determination of Amyloid Fibrils with Magic-Angle Spinning and Dynamic Nuclear Polarization NMR
Intermolecular Structure Determination of Amyloid Fibrils with Magic-Angle Spinning and Dynamic Nuclear Polarization NMR
Marvin J. Bayro, Galia T. Debelouchina, Matthew T. Eddy, Neil R. Birkett, Catherine E. MacPhee, Melanie Rosay, Werner E. Maas, Christopher M. Dobson and Robert G. Griffin
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja203756x/aop/images/medium/ja-2011-03756x_0002.gif
Journal of the American Chemical Society
DOI: 10.1021/ja203756x
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA...
nmrlearner
Journal club
0
08-13-2011 02:47 AM
Intermolecular structure determination of amyloid fibrils with magic-angle spinning and dynamic nuclear polarization NMR.
Intermolecular structure determination of amyloid fibrils with magic-angle spinning and dynamic nuclear polarization NMR.
Intermolecular structure determination of amyloid fibrils with magic-angle spinning and dynamic nuclear polarization NMR.
J Am Chem Soc. 2011 Jul 21;
Authors: Bayro MJ, Debelouchina GT, Eddy MT, Birkett NR, Macphee CE, Rosay MM, Maas WE, Dobson CM, Griffin RG
We describe magic-angle spinning NMR experiments designed to elucidate the interstrand architecture of amyloid fibrils. Three methods are introduced for this purpose, two...
nmrlearner
Journal club
0
07-23-2011 08:54 AM
Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.
Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.
Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.
Anal Chem. 2011 Jun 7;
Authors: Ragavan M, Chen HY, Sekar G, Hilty C
Hyperpolarization of nuclear spins through techniques such as Dynamic Nuclear Polarization (DNP) can greatly increase the signal to noise ratio in NMR measurements, thus eliminating the need for signal averaging. This enables the study of many dynamic processes which would otherwise not be amenable to study by NMR spectroscopy....
nmrlearner
Journal club
0
06-10-2011 11:52 AM
[NMR paper] Polarization of cinnamoyl-CoA substrates bound to enoyl-CoA hydratase: correlation of
Polarization of cinnamoyl-CoA substrates bound to enoyl-CoA hydratase: correlation of (13)C NMR with quantum mechanical calculations and calculation of electronic strain energy.
Related Articles Polarization of cinnamoyl-CoA substrates bound to enoyl-CoA hydratase: correlation of (13)C NMR with quantum mechanical calculations and calculation of electronic strain energy.
Biochemistry. 2002 Feb 26;41(8):2630-40
Authors: D'Ordine RL, Pawlak J, Bahnson BJ, Anderson VE
When alpha,beta-unsaturated substrates bind to the active site of enoyl-CoA...