Time domain removal of irrelevant magnetization in chemical exchange saturation transfer Z-spectra
Version of Record online: 24 JUN 2013
© 2013 Wiley Periodicals, Inc.
Magnetic Resonance in Medicine
Volume 70, Issue 2, pages 547–555, August 2013
How to Cite
Yadav, N. N., Chan, K. W. Y., Jones, C. K., McMahon, M. T. and van Zijl, P. C. M. (2013), Time domain removal of irrelevant magnetization in chemical exchange saturation transfer Z-spectra. Magn Reson Med, 70: 547–555. doi: 10.1002/mrm.24812
- Issue online: 23 JUL 2013
- Version of Record online: 24 JUN 2013
- Manuscript Accepted: 26 APR 2013
- Manuscript Revised: 2 APR 2013
- Manuscript Received: 5 FEB 2013
- NIH. Grant Numbers: R01EB015032, R01EB015031, P50CA103175, P41015909
- time domain analysis;
- magnetization transfer;
- discrete inverse Fourier transform
To evaluate the possibility of processing Z-spectra using time domain analysis.
An inverse Fourier transform (IFT) is applied on Z-spectra, thus transforming the chemical exchange saturation transfer (CEST) data into the time domain. Here, large interfering signals from solvent and semisolid magnetization transfer can be fit and filtered out. The method is demonstrated on a range of phantoms (creatine, a para-CEST agent, and hen egg white) and also in vivo on a mouse brain.
Using time domain analysis, signal components in Z-spectra could be fit very well, thus enabling irreverent or nuisance components to be removed. The method worked equally well for samples in a solution or a gel where the large contribution from conventional magnetization transfer contrast (MTC) was easily separated out. Results from egg white and mouse brain in vivo data showed that the large water resonance could easily be removed thus allowing the remaining signal to be analyzed without interference from direct water saturation.
This method successfully filtered out the large nuisance signals from bulk water and MTC in Z-spectra in a large variety of phantom types and also in vivo. It is expected to be a potentially powerful tool for CEST studies without needing asymmetry analysis. Magn Reson Med 70:547–555, 2013. © 2013 Wiley Periodicals, Inc.