Field strength dependence of PRESS timings for simultaneous detection of glutamate and glutamine from 1.5 to 7T

Snyder, Jeff; Wilman, Alan H.

doi:10.1016/j.jmr.2009.12.002

Cited by 65 publications

(57 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the sequences considered by us, a reasonable choice, providing good accuracy and repeatability, is the PRESS, TE ¼ 80 ms sequence. Interestingly, this timing is the closest (among those considered by us) to that found to be optimal for Glu/Gln separation at 3 T through wileyonlinelibrary.com/journal/nbm THE CASE OF THE MISSING GLUTAMINE experiments (11) and simulations (19). It should be noted that our repeatability measures (simulated and measured experimentally) depict intravolunteer, intrasession effects.…”

Section: In Vivo Experimentssupporting

confidence: 55%

The case of the missing glutamine

Hancu

Port

2011

NMR in Biomedicine

View full text Add to dashboard Cite

A theoretical study was performed to determine the accuracy and repeatability of multiple one-dimensional pulse sequences in the quantification of glutamine concentration at 3 T. Variable repeatability (12% to > 50%) and significant absolute error (-50% to +70%) were noted for the eight pulse sequences considered. Data acquired in vivo using three of the pulse sequences used for simulation matched the predicted repeatability well; among the pulse sequences considered, point-resolved spectroscopy (TE = 80 ms) offered minimal error and acceptable repeatability (12%) for brain glutamine measurements. Following correction for the expected bias of each pulse sequence, consistent glutamine measurements, in the 1-mM range, were reported with the three sequences. An explanation for the mismatch between in vivo (1)H MRS and in vitro (13)C/(1)H MRS at high field was attempted.

show abstract

Section: In Vivo Experimentssupporting

confidence: 55%

The case of the missing glutamine

Hancu

Port

2011

NMR in Biomedicine

View full text Add to dashboard Cite

show abstract

“…For spectra with short TEs <40ms Glu and Gln peaks overlap by <30% in the 2.25-2.55 ppm range over which they are most distinct, and contribute around 90% and 10%, respectively, to the combined Glx signal. 62 Based on this, the contamination of Glu by Gln in the present data is estimated as less than 10%. In our data, Glx/Cr ratio was not estimated for 29 out of 37 participants.…”

Section: Limitationsmentioning

confidence: 55%

Treatment-Resistant Schizophrenia Patients Show Elevated Anterior Cingulate Cortex Glutamate Compared to Treatment-Responsive

Mouchlianitis¹,

Bloomfield²,

Law³

et al. 2015

SCHBUL

190

140

View full text Add to dashboard Cite

“…Finally, using our approach of PRESS with an echo time of 30 ms at 3 Tesla, the partially overlapping signals from Glu and Gln cannot be entirely resolved, with contamination of the Glu signal by Gln estimated as <10%. 71 …”

Section: Discussionmentioning

confidence: 99%

Corticolimbic hyper-response to emotion and glutamatergic function in people with high schizotypy: a multimodal fMRI-MRS study

et al. 2017

View full text Add to dashboard Cite

Animal models and human neuroimaging studies suggest that altered levels of glutamatergic metabolites within a corticolimbic circuit have a major role in the pathophysiology of schizophrenia. Rodent models propose that prefrontal glutamate dysfunction could lead to amygdala hyper-response to environmental stress and underlie hippocampal overdrive in schizophrenia. Here we determine whether changes in brain glutamate are present in individuals with high schizotypy (HS), which refers to the presence of schizophrenia-like characteristics in healthy individuals, and whether glutamate levels are related to altered corticolimbic response to emotion. Twenty-one healthy HS subjects and 22 healthy subjects with low schizotypy (LS) were selected based on their Oxford and Liverpool Inventory of Feelings and Experiences rating. Glutamate levels were measured in the anterior cingulate cortex (ACC) using proton magnetic resonance spectroscopy, followed by a functional magnetic resonance imaging (fMRI) scan to measure corticolimbic response during emotional processing. fMRI results and fMRI × glutamate interactions were considered significant after voxel-wise P<0.05 family-wise error correction. While viewing emotional pictures, HS individuals showed greater activation than did subjects with LS in the caudate, and marginally in the ACC, hippocampus, medial prefrontal cortex (MPFC) and putamen. Although no between-group differences were found in glutamate concentrations, within the HS group ACC glutamate was negatively correlated with striatal activation (left: z=4.30, P=0.004 and right: z=4.12 P=0.008 caudate; left putamen: z=3.89, P=0.018) and marginally with MPFC (z=3.55, P=0.052) and amygdala (left: z=2.88, P=0.062; right: z=2.79, P=0.079), correlations that were not present in LS subjects. These findings provide, to our knowledge, the first evidence that brain glutamate levels are associated with hyper-responsivity in brain regions thought to be critical in the pathophysiology of psychosis.

show abstract

Field strength dependence of PRESS timings for simultaneous detection of glutamate and glutamine from 1.5 to 7T

Cited by 65 publications

References 31 publications

The case of the missing glutamine

The case of the missing glutamine

Treatment-Resistant Schizophrenia Patients Show Elevated Anterior Cingulate Cortex Glutamate Compared to Treatment-Responsive

Corticolimbic hyper-response to emotion and glutamatergic function in people with high schizotypy: a multimodal fMRI-MRS study

Contact Info

Product

Resources

About