Use of tissue water as a concentration reference for proton spectroscopic imaging
Article first published online: 10 MAY 2006
Copyright © 2006 Wiley-Liss, Inc.
Magnetic Resonance in Medicine
Volume 55, Issue 6, pages 1219–1226, June 2006
How to Cite
Gasparovic, C., Song, T., Devier, D., Bockholt, H. J., Caprihan, A., Mullins, P. G., Posse, S., Jung, R. E. and Morrison, L. A. (2006), Use of tissue water as a concentration reference for proton spectroscopic imaging. Magn Reson Med, 55: 1219–1226. doi: 10.1002/mrm.20901
- Issue published online: 22 MAY 2006
- Article first published online: 10 MAY 2006
- Manuscript Accepted: 20 FEB 2006
- Manuscript Revised: 17 FEB 2006
- Manuscript Received: 3 NOV 2005
- tissue water;
- spectroscopic imaging;
- relaxation times;
A strategy for using tissue water as a concentration standard in 1H magnetic resonance spectroscopic imaging studies on the brain is presented, and the potential errors that may arise when the method is used are examined. The sensitivity of the method to errors in estimates of the different water compartment relaxation times is shown to be small at short echo times (TEs). Using data from healthy human subjects, it is shown that different image segmentation approaches that are commonly used to account for partial volume effects (SPM2, FSL's FAST, and K-means) lead to different estimates of metabolite levels, particularly in gray matter (GM), owing primarily to variability in the estimates of the cerebrospinal fluid (CSF) fraction. While consistency does not necessarily validate a method, a multispectral segmentation approach using FAST yielded the lowest intersubject variability in the estimates of GM metabolites. The mean GM and white matter (WM) levels of N-acetyl groups (NAc, primarily N-acetylaspartate), choline (Ch), and creatine (Cr) obtained in these subjects using the described method with FAST multispectral segmentation are reported: GM [NAc] = 17.16 ± 1.19 mM; WM [NAc] = 14.26 ± 1.38 mM; GM [Ch] = 3.27 ± 0.47 mM; WM [Ch] = 2.65 ± 0.25 mM; GM [Cr] = 13.98 ± 1.20 mM; and WM [Cr] = 7.10 ± 0.67 mM. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc.