Article: Water saturation shift referencing (WASSR) for chemical exchange saturation transfer (CEST) experiments
| Title | Water saturation shift referencing (WASSR) for chemical exchange saturation transfer (CEST) experiments | ||||||
|---|---|---|---|---|---|---|---|
| Authors | Kim, M1 2 Gillen, J1 2 Landman, BA2 Zhou, J1 2 Van Zijl, PCM1 2 | ||||||
| Issue Date | 2009 | ||||||
| Publisher | John Wiley & Sons, Inc. The Journal's web site is located at http://www.interscience.wiley.com/jpages/0740-3194/ | ||||||
| Citation | Magnetic Resonance In Medicine, 2009, v. 61 n. 6, p. 1441-1450 [How to Cite?] DOI: http://dx.doi.org/10.1002/mrm.21873 | ||||||
| Abstract | Chemical exchange saturation transfer (CEST) is a contrast mechanism that exploits exchange-based magnetization transfer (MT) between solute and water protons. CEST effects compete with direct water saturation and conventional MT processes, and generally can only be quantified through an asymmetry analysis of the water saturation spectrum (Z-spectrum) with respect to the water frequency, a process that is exquisitely sensitive to magnetic field inhomogeneities. Here it is shown that direct water saturation imaging allows measurement of the absolute water frequency in each voxel, allowing proper centering of Z-spectra on a voxel-by-voxel basis independently of spatial B0 field variations. Optimal acquisition parameters for this "water saturation shift referencing" (WASSR) approach were estimated using Monte Carlo simulations and later confirmed experimentally. The optimal ratio of the WASSR sweep width to the linewidth of the direct saturation curve was found to be 3.3- 4.0, requiring a sampling of 16-32 points. The frequency error was smaller than 1 Hz at signal-to-noise ratios of 40 or higher. The WASSR method was applied to study glycogen, where the chemical shift difference between the hydroxyl (OH) protons and bulk water protons at 3T is so small (0.75-1.25 ppm) that the CEST spectrum is inconclusive without proper referencing. © 2009 Wiley-Liss, Inc. | ||||||
| ISSN | 0740-3194 2011 Impact Factor: 2.964 2011 SCImago Journal Rankings: 0.279 | ||||||
| DOI | http://dx.doi.org/10.1002/mrm.21873 | ||||||
| ISI Accession Number ID | WOS:000266429900019
Funding Information: Grant sponsor: National Institutes of Health; Grant numbers: NIH-NCRR P41-RR15241; NIH-NIBIB R01-EB02634; R21-EB02666; Grant sponsor: Philips Medical Systems. | ||||||
| References | References in Scopus |
| dc.contributor.author | Kim, M | ||||||
|---|---|---|---|---|---|---|---|
| dc.contributor.author | Gillen, J | ||||||
| dc.contributor.author | Landman, BA | ||||||
| dc.contributor.author | Zhou, J | ||||||
| dc.contributor.author | Van Zijl, PCM | ||||||
| dc.date.accessioned | 2012-06-26T06:14:21Z | ||||||
| dc.date.available | 2012-06-26T06:14:21Z | ||||||
| dc.date.issued | 2009 | ||||||
| dc.description.abstract | Chemical exchange saturation transfer (CEST) is a contrast mechanism that exploits exchange-based magnetization transfer (MT) between solute and water protons. CEST effects compete with direct water saturation and conventional MT processes, and generally can only be quantified through an asymmetry analysis of the water saturation spectrum (Z-spectrum) with respect to the water frequency, a process that is exquisitely sensitive to magnetic field inhomogeneities. Here it is shown that direct water saturation imaging allows measurement of the absolute water frequency in each voxel, allowing proper centering of Z-spectra on a voxel-by-voxel basis independently of spatial B0 field variations. Optimal acquisition parameters for this "water saturation shift referencing" (WASSR) approach were estimated using Monte Carlo simulations and later confirmed experimentally. The optimal ratio of the WASSR sweep width to the linewidth of the direct saturation curve was found to be 3.3- 4.0, requiring a sampling of 16-32 points. The frequency error was smaller than 1 Hz at signal-to-noise ratios of 40 or higher. The WASSR method was applied to study glycogen, where the chemical shift difference between the hydroxyl (OH) protons and bulk water protons at 3T is so small (0.75-1.25 ppm) that the CEST spectrum is inconclusive without proper referencing. © 2009 Wiley-Liss, Inc. | ||||||
| dc.description.nature | Link_to_subscribed_fulltext | ||||||
| dc.identifier.citation | Magnetic Resonance In Medicine, 2009, v. 61 n. 6, p. 1441-1450 [How to Cite?] DOI: http://dx.doi.org/10.1002/mrm.21873 | ||||||
| dc.identifier.doi | http://dx.doi.org/10.1002/mrm.21873 | ||||||
| dc.identifier.epage | 1450 | ||||||
| dc.identifier.isi | WOS:000266429900019
Funding Information: Grant sponsor: National Institutes of Health; Grant numbers: NIH-NCRR P41-RR15241; NIH-NIBIB R01-EB02634; R21-EB02666; Grant sponsor: Philips Medical Systems. | ||||||
| dc.identifier.issn | 0740-3194 2011 Impact Factor: 2.964 2011 SCImago Journal Rankings: 0.279 | ||||||
| dc.identifier.issue | 6 | ||||||
| dc.identifier.pmid | 19358232 | ||||||
| dc.identifier.scopus | eid_2-s2.0-67049160813 | ||||||
| dc.identifier.spage | 1441 | ||||||
| dc.identifier.uri | http://hdl.handle.net/10722/150911 | ||||||
| dc.identifier.volume | 61 | ||||||
| dc.language | eng | ||||||
| dc.publisher | John Wiley & Sons, Inc. The Journal's web site is located at http://www.interscience.wiley.com/jpages/0740-3194/ | ||||||
| dc.publisher.place | United States | ||||||
| dc.relation.ispartof | Magnetic Resonance in Medicine | ||||||
| dc.relation.references | References in Scopus | ||||||
| dc.subject.mesh | Adult | ||||||
| dc.subject.mesh | Algorithms | ||||||
| dc.subject.mesh | Body Water - Metabolism | ||||||
| dc.subject.mesh | Female | ||||||
| dc.subject.mesh | Humans | ||||||
| dc.subject.mesh | Image Enhancement - Methods | ||||||
| dc.subject.mesh | Image Interpretation, Computer-Assisted - Methods | ||||||
| dc.subject.mesh | Magnetic Resonance Imaging - Methods | ||||||
| dc.subject.mesh | Male | ||||||
| dc.subject.mesh | Muscle, Skeletal - Anatomy & Histology - Metabolism | ||||||
| dc.subject.mesh | Reproducibility Of Results | ||||||
| dc.subject.mesh | Sensitivity And Specificity | ||||||
| dc.subject.mesh | Water - Analysis | ||||||
| dc.title | Water saturation shift referencing (WASSR) for chemical exchange saturation transfer (CEST) experiments | ||||||
| dc.type | Article |
Author Affiliations
- Kennedy Krieger Institute
- The Johns Hopkins School of Medicine