Deuterium metabolic imaging of the human brain in vivo at 7 T
Eulalia Serés Roig, Henk M. De Feyter, Terence W. Nixon, Loreen Ruhm, Anton V. Nikulin, Klaus Scheffler, Nikolai I. Avdievich, Anke Henning, Robin A. de Graaf
Abstract
Purpose
To explore the potential of deuterium metabolic imaging (DMI) in the human brain in vivo at 7 T, using a multi-element deuterium (2H) RF coil for 3D volume coverage.
Methods
1H-MR images and localized 2H MR spectra were acquired in vivo in the human brain of 3 healthy subjects to generate DMI maps of 2H-labeled water, glucose, and glutamate/glutamine (Glx). In addition, non-localized 2H-MR spectra were acquired both in vivo and in vitro to determine T1 and T2 relaxation times of deuterated metabolites at 7 T. The performance of the 2H coil was assessed through numeric simulations and experimentally acquired B1+ maps.
Results
3D DMI maps covering the entire human brain in vivo were obtained from well-resolved deuterated (2H) metabolite resonances of water, glucose, and Glx. The T1 and T2 relaxation times were consistent with those reported at adjacent field strengths. Experimental B1+ maps were in good agreement with simulations, indicating efficient and homogeneous B1+ transmission and low RF power deposition for 2H, consistent with a similar array coil design reported at 9.4 T.
Conclusion
Here, we have demonstrated the successful implementation of 3D DMI in the human brain in vivo at 7 T. The spatial and temporal nominal resolutions achieved at 7 T (i.e., 2.7 mL in 28 min, respectively) were close to those achieved at 9.4 T and greatly outperformed DMI at lower magnetic fields. DMI at 7 T and beyond has clear potential in applications dealing with small brain lesions.