Evidence map›Paper›PMID 30995237›Full record

Trial reportPloS one2019

Quantification of in vivo transverse relaxation of glutamate in the frontal cortex of human brain by radio frequency pulse-driven longitudinal steady state.

Ningzhi Li, Linqing Li, Yan Zhang, Maria Ferraris Araneta, Christopher Johnson, Jun Shen

Open access · goldAbstract readClinical Trial
In one paragraph

Trial report in PloS one, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed, 1 pooled it
0.3field-weighted citation impact, top 38% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 1 synthesis or guideline pooled it, 4 citations in OpenAlex.

  1. Pooled it
  2. Article
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 1 institution in 1 country.

Ningzhi LiSection on Magnetic Spectroscopy, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America.ORCID 0000-0003-3848-5384
Linqing LiFunctional Magnetic Resonance Imaging Core Facility, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America.
Yan ZhangMagnetic Resonance Spectroscopy Core, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America.
Maria Ferraris AranetaMagnetic Resonance Spectroscopy Core, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America.
Christopher JohnsonSection on Magnetic Spectroscopy, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America.
Jun ShenSection on Magnetic Spectroscopy, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America.
National Institutes of Health · US

Funding

Magnetic Resonance Spectroscopy and Imaging Studies of Brain FunctionsZIAMH002803 · NIMH · NATIONAL INSTITUTE OF MENTAL HEALTH · PI SHEN, JUN · 2009 to 2025
$24.9M
Magnetic Resonance Spectroscopy Core FacilityZICMH002894 · NIMH · NATIONAL INSTITUTE OF MENTAL HEALTH · PI SHEN, JUN · 2009 to 2024
$13.5M
6 · The paper itself

Abstract

purposeThe principal excitatory neurotransmitter glutamate plays an important role in many central nervous system disorders. Because glutamate resides predominantly in glutamatergic neurons, its relaxation properties reflect the intracellular environment of glutamatergic neurons. This study developed an improved echo time-independent technique for measuring transverse relaxation time and demonstrated that this radio frequency (RF)-driven longitudinal steady state technique can reliably measure glutamate transverse relaxation in the frontal cortex, where structural and functional abnormalities have been associated with psychiatric symptoms.

methodBloch and Monte Carlo simulations were performed to improve and optimize the RF-driven, longitudinal, steady-state (MARzss) technique to significantly shorten scan time and increase measurement precision. Optimized four-flip angle measurements at 0°,12°, 24°, and 36° with matched repetition time were used in nine human subjects (6F, 3M; 27-49 years old) at 7 Tesla. Longitudinal and transverse relaxation rates for glutamate were measured from a 2 x 2 x 2 cm3 voxel placed in three different brain regions: gray matter-dominated medial prefrontal lobe, white matter-dominated left frontal lobe, and gray matter-dominated occipital lobe.

resultsCompared to the original MARzss technique, the scan time per voxel for measuring glutamate transverse relaxation was shortened by more than 50%. In the medial frontal, left frontal, and occipital voxels, the glutamate T2 was found to be 117.5±12.9 ms (mean ± standard deviation, n = 9), 107.3±12.1 (n = 9), and 124.4±16.6 ms (n = 8), respectively.

conclusionsThe improvements described in this study make the MARZSS technique a viable tool for reliably measuring glutamate relaxation from human subjects in a typical clinical setting. It is expected that this improved technique can be applied to characterize the intracellular environment of glutamatergic neurons in a variety of brain disorders.

Indexed as

Frontal LobeMagnetic Resonance ImagingWhite MatterAdultFemaleGlutamic AcidHumansMaleMiddle AgedOccipital LobeGlutamic Acid

Identifiers

PMID30995237
PMCPMC6469797
OpenAlexW2937814347

What OpenQuestion holds

Textmetadata
LicenceCC0
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.