Related Experiment Video
Updated: Aug 15, 2026

Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
Echo-time independent signal modulations using PRESS sequences: a new approach to spectral editing of strongly
G Gambarota1, M van der Graaf, D Klomp
1Department of Radiology, Radboud University Nijmegen Medical Center, The Netherlands. giulio.gambarota@epfl.ch
Abstract:
In clinical MR spectroscopy, double spin-echo point resolved spectroscopy (PRESS) sequences are routinely used for volume selection. For strongly coupled AB spin systems under PRESS excitation, the dependence of the signal on the echo time TE has been thoroughly investigated, whereas less attention has been paid to the signal modulation which occurs at constant TE with varying interpulse delays. A substantial TE-independent J modulation is here predicted from analytical solutions of the Liouville equation and density matrix simulations, and verified with experiments on citrate at 1.5 and 3T. It is also shown that this modulation effect could be exploited for editing of strongly coupled AB resonances or for removal of singlets in spectra-by means of difference spectroscopy-just using a standard PRESS sequence. The applicability in vivo of this new spectral editing approach is also demonstrated, with selective detection of citrate resonances in the human prostate. This novel approach has the advantages of being simple, and directly applicable on standard clinical MR scanners, provided that the exact behavior of the resonance is known.
More Related Videos
Related Concept Videos
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
NMR Spectroscopy: Spin–Spin Coupling
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
π Electron Effects on Chemical Shift: Overview

