Improve the selectively refocused INEPT pulse sequence for detecting phosphomonoesters and phosphodiesters
Article first published online: 21 DEC 2011
Copyright © 2011 Wiley Periodicals, Inc.
Magnetic Resonance in Medicine
Volume 68, Issue 2, pages 332–338, August 2012
How to Cite
Mao, X.-a. (2012), Improve the selectively refocused INEPT pulse sequence for detecting phosphomonoesters and phosphodiesters. Magn Reson Med, 68: 332–338. doi: 10.1002/mrm.23233
- Issue published online: 12 JUL 2012
- Article first published online: 21 DEC 2011
- Manuscript Accepted: 6 SEP 2011
- Manuscript Revised: 20 JUL 2011
- Manuscript Received: 3 MAR 2011
- 31P magnetic resonance spectroscopy;
- selectively refocused insensitive nuclei enhanced polarization transfer;
- selective refocusing;
In application of the 31P selectively refocused insensitive nuclei enhanced polarization transfer (srINEPT) technique to the detection of phosphomono- and diesters in tissues, homonuclear couplings between the CH2O protons and the NCH2 protons seriously attenuate the sensitivity. These couplings can be conventionally removed by two soft 180° pulses in the 1H evolution period which selectively invert the NCH2 magnetizations. However, the srINEPT pulse sequence can be simplified by replacing the pulse train “soft 180°-hard 180°-soft 180°” with a single soft 180° pulse that selectively inverts the CH2O magnetizations. Theoretical analysis in this study demonstrates the correctness of this approach in principle. Validation on a milk phantom allowed us to investigate and discuss advantages and disadvantages of the proposed srINEPT with respect to the original srINEPT. Furthermore, comparison of different selective pulses made it possible to demonstrate that the proposed srINEPT experiment is not sensitive to errors in pulse length, offset, and B1 field strength of the selective pulse when ReBurp pulse is used for selective refocusing. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.