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 Nikulin, Klaus Scheffler, Nikolai I. Avdievich, A 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 ( 2 H) RF coil for 3D volume coverage. Methods 1 H‐MR images and localized 2 H MR spectra were acquired in vivo in the human brain of 3 healthy subjects to generate DMI maps of 2 H‐labeled water, glucose, and glutamate/glutamine (Glx). In addition, non‐localized 2 H‐MR spectra were acquired both in vivo and in vitro to determine T 1 and T 2 relaxation times of deuterated metabolites at 7 T. The performance of the 2 H coil was assessed through numeric simulations and experimentally acquired B 1 + maps. Results 3D DMI maps covering the entire human brain in vivo were obtained from well‐resolved deuterated ( 2 H) metabolite resonances of water, glucose, and Glx. The T 1 and T 2 relaxation times were consistent with those reported at adjacent field strengths. Experimental B 1 + maps were in good agreement with simulations, indicating efficient and homogeneous B 1 + transmission and low RF power deposition for 2 H, 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.