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.