Use of quantitative brain water imaging as concentration reference for J-edited MR spectroscopy of GABA
| Autor: | Alfons Schnitzler, Georg Oeltzschner, Helge J. Zöllner, Hans Jörg Wittsack, Frithjof Wickrath |
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| Rok vydání: | 2016 |
| Předmět: |
Male
In vivo magnetic resonance spectroscopy Magnetic Resonance Spectroscopy Body water Biomedical Engineering Biophysics Brain water gamma-Aminobutyric acid 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Nuclear magnetic resonance Body Water Reference Values In vivo medicine Humans Radiology Nuclear Medicine and imaging Water density Water content gamma-Aminobutyric Acid Chemistry Relaxation (NMR) Brain Evaluation Studies as Topic Hepatic Encephalopathy Female 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Magnetic Resonance Imaging. 34:1057-1063 |
| ISSN: | 0730-725X |
| Popis: | To compare two different methods of obtaining the water reference for determination of quantitative water-scaled in vivo concentration estimates of γ-aminobutyric acid (GABA).Water-scaled GABA estimates from localized J-difference edited MR spectroscopy experiments can be computed using standard values for tissue-specific water content and relaxation times. Water content and relaxation may, however, be altered in pathology. This work re-analyzed data from a recent study in healthy controls and patients with minimal (mHE) or grade I (HE 1) hepatic encephalopathy, a disease associated with slight elevation of brain water content. J-difference edited MR spectroscopy data were combined with quantitative brain water measures, which provided individual water density references and T1 relaxation times. Resulting GABA estimates were compared to concentration values obtained using standard tissue-specific water content and relaxation values.Occipital GABA concentration values obtained from individual water and T1 maps were 1.64±0.35mM in controls, and significantly higher (P0.01) than in mHE (1.15±0.28mM) and HE 1 patients (1.18±0.09mM). Results from the tissue-dependent approach (1.58±0.30mM (controls), 1.10±0.27mM (mHE) and 1.12±0.12mM (HE 1)) were slightly lower (P0.05 in each group).Water-scaled in vivo GABA estimates can be obtained with individual water density and T1 relaxation mapping. This approach may be useful for studying GABA levels in pathologies with substantial brain water content or relaxation changes. |
| Databáze: | OpenAIRE |
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