Article (Published version) (881 Kb) - Limited access to UNIGE
A comparison of in vivo 13C MR brain glycogen quantification at 9.4 and 14.1 T.
|Published in||Magnetic Resonance in Medicine. 2012, vol. 67, no. 6, p. 1523-7|
|Abstract||The high molecular weight and low concentration of brain glycogen render its noninvasive quantification challenging. Therefore, the precision increase of the quantification by localized (13) C MR at 9.4 to 14.1 T was investigated. Signal-to-noise ratio increased by 66%, slightly offset by a T(1) increase of 332 ± 15 to 521 ± 34 ms. Isotopic enrichment after long-term (13) C administration was comparable (≈ 40%) as was the nominal linewidth of glycogen C1 (≈ 50 Hz). Among the factors that contributed to the 66% observed increase in signal-to-noise ratio, the T(1) relaxation time impacted the effective signal-to-noise ratio by only 10% at a repetition time = 1 s. The signal-to-noise ratio increase together with the larger spectral dispersion at 14.1 T resulted in a better defined baseline, which allowed for more accurate fitting. Quantified glycogen concentrations were 5.8 ± 0.9 mM at 9.4 T and 6.0 ± 0.4 mM at 14.1 T; the decreased standard deviation demonstrates the compounded effect of increased magnetization and improved baseline on the precision of glycogen quantification.|
|Keywords||Algorithms — Animals — Brain/anatomy & histology/metabolism — Carbon Isotopes/analysis/diagnostic use — Glycogen/analysis — Image Enhancement/methods — Image Interpretation, Computer-Assisted/methods — Magnetic Resonance Imaging/methods — Magnetic Resonance Spectroscopy/methods — Male — Rats — Rats, Sprague-Dawley — Reproducibility of Results — Sensitivity and Specificity|
|VAN HEESWIJK, Ruud B et al. A comparison of in vivo 13C MR brain glycogen quantification at 9.4 and 14.1 T. In: Magnetic Resonance in Medicine, 2012, vol. 67, n° 6, p. 1523-7. https://archive-ouverte.unige.ch/unige:32276|