Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

991
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
991
¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons01:03

¹H NMR Chemical Shift Equivalence: Homotopic and Heterotopic Protons

2.3K
Protons in identical electronic environments within a molecule are chemically equivalent and have the same chemical shift. The replacement test is a useful tool to identify chemical equivalence and predict NMR spectra. A substituent replaces each of the protons being examined and the resulting molecules are compared. If the same molecule is obtained, the protons are equivalent or homotopic. Replacement of any hydrogens in ethane by chlorine yields chloroethane because all six protons are...
2.3K
¹H NMR of Labile Protons: Deuterium (²H) Substitution00:48

¹H NMR of Labile Protons: Deuterium (²H) Substitution

860
This lesson illustrates the role of deuterium substitution in simplifying the NMR spectrum of compounds comprising labile protons. One method employed is the use of deuterium. Amongst the three isotopes of hydrogen, deuterium (2H) has a nucleus composed of one proton and one neutron. When the D2O solvent is added to a pure dry ethanol solution, its labile proton is substituted with deuterium.
860
2D NMR: Overview of Homonuclear Correlation Techniques01:16

2D NMR: Overview of Homonuclear Correlation Techniques

150
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
150
¹³C NMR: ¹H–¹³C Decoupling01:04

¹³C NMR: ¹H–¹³C Decoupling

991
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
991
Effects of EDTA on End-Point Detection Methods01:18

Effects of EDTA on End-Point Detection Methods

235
Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration.
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a...
235

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

EGFR inhibition down-regulates MGMT and enhances responsiveness to temozolomide in glioblastoma.

Science translational medicine·2026
Same author

Intracranial hemorrhage in acquired hemophilia A: illustrative case.

Journal of neurosurgery. Case lessons·2026
Same author

Enhancing 1p/19q Classification in Brain Gliomas Using IDH Status: A Deep Learning Study.

AJNR. American journal of neuroradiology·2026
Same author

The University of Texas Southwestern Glioma Dataset - MRI, Molecular Markers and Segmentations.

Scientific data·2026
Same author

Optimized Detection of Left Ventricular Hyperpolarized [1-<sup>13</sup>C]Pyruvate Signal in Human Cardiac Metabolic Imaging.

Magnetic resonance in medicine·2026
Same author

Deuterium 1-Channel Transmit/16-Channel High Impedance Receive Array Combined With 16-Channel <sup>1</sup>H Dual-Row Transceiver Array for 7 Tesla Brain Imaging.

Magnetic resonance in medicine·2026

Related Experiment Video

Updated: May 22, 2025

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents
08:59

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents

Published on: April 15, 2016

6.8K

TE optimization for J-difference editing of 2-hydroxyglutarate at 3T.

Kimberly L Chan1,2, Rutul Hapani3, Elizabeth A Maher4,5

  • 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.

Magnetic Resonance in Medicine
|May 21, 2025
PubMed
Summary

A 90 ms echo time (TE) optimizes 2-hydroxyglutarate (2HG) detection in brain imaging, maximizing the 2HG signal while minimizing overlap with Glx and reducing unwanted signals like lipid and water. This TE enhances spectral fitting accuracy for better diagnostic insights.

Keywords:
2HGJ‐difference editingMR spectroscopygliomatumor

More Related Videos

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism
13:56

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

Published on: November 19, 2014

20.1K
Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
09:30

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease

Published on: December 18, 2016

19.3K

Related Experiment Videos

Last Updated: May 22, 2025

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents
08:59

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents

Published on: April 15, 2016

6.8K
The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism
13:56

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

Published on: November 19, 2014

20.1K
Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
09:30

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease

Published on: December 18, 2016

19.3K

Area of Science:

  • Magnetic Resonance Spectroscopy (MRS)
  • Neuroimaging
  • Metabolomics

Background:

  • 2-hydroxyglutarate (2HG) is a potential biomarker in various cancers, particularly glioma.
  • Accurate quantification of 2HG using MRS is crucial for diagnosis and monitoring treatment response.
  • The MEGA-PRESS sequence is commonly used for 2HG detection, but its performance is sensitive to acquisition parameters like echo time (TE).

Purpose of the Study:

  • To determine the optimal echo time (TE) for the MEGA-PRESS sequence to maximize the 2-hydroxyglutarate (2HG) signal.
  • To evaluate the TE dependence of 2HG signal separation from co-edited glutamate plus glutamine (Glx).
  • To assess the impact of TE on spectral fitting accuracy and nuisance signal contamination.

Main Methods:

  • Simulations were conducted across a range of echo times (70-160 ms) to model signal intensity and 2HG-Glx overlap.
  • In vivo data were acquired from glioma patients at different TEs (70, 90, and 120 ms) to validate simulation findings.
  • Analysis focused on signal intensity, spectral overlap, fit accuracy, and relaxation times (T2) of key metabolites and water.

Main Results:

  • An echo time (TE) of 90 ms yielded a maximal 2HG signal, 23% greater than at 70 ms, without significantly increasing 2HG-Glx spectral overlap.
  • At 90 ms, lipid and residual water signals were reduced by 26% and 16%, respectively, compared to 70 ms.
  • Spectral fitting quality improved significantly at 90 ms, indicated by a 49% decrease in fit-quality numbers.

Conclusions:

  • An echo time (TE) of 90 ms is optimal for MEGA-PRESS MRS of 2HG.
  • This TE provides the best balance of maximal 2HG signal, minimal 2HG-Glx overlap, and reduced contamination from lipid and water signals.
  • The findings support the use of a 90 ms TE for improved in vivo 2HG quantification in glioma patients.