1H NMR spectroscopic imaging of the mouse brain at 9.4 T.
OBJECTIVE
To assess the feasibility of 1H spectroscopic imaging (SI) in the mouse brain at 9.4 T, and investigate regional variations in brain metabolites.


METHODS
A total of 21 SI studies were performed in CD-1 mice to evaluate the basal ganglia (N=5), hippocampus and thalamus (N=11), and cerebellum (N=5). We adjusted the B0 homogeneity for each slice using a fully automated shim calculation method based on the B0 map, which we measured using a multislice gradient-echo sequence with multiple phase evolution delays. The SI employed a modified localization by adiabatic selective refocusing (LASER) sequence with TE/TR of 50/2000 msec, 24x24 encodes over a field of view (FOV) of 24 mmx24 mm, 1 microL voxel resolution, and two averages, for a total acquisition time of 38 minutes.


RESULTS
Sufficient shimming was achieved and high-quality spectra were consistently obtained in each slice. N-acetyl aspartate (NAA)/creatine (Cr) ratios in the basal ganglia and thalamus (0.86+/-0.07, and 0.87+/-0.07, respectively) were significantly higher than those in the hippocampus and cerebellum (0.76+/-0.03 and 0.67+/-0.07), which were also significantly different from each other.


CONCLUSIONS
1H SI of the mouse brain is highly reproducible and allows differences in regional metabolite ratios to be easily visualized.
Miyasaka
Naoyuki
N
Department of Radiology, Albert Einstein College of Medicine, Bronx, New York 10461, USA. n.miyasaka.gyne@tmd.ac.jp
Takahashi
Kan
K
Hetherington
Hoby P
HP
D000704:Analysis of Variance; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000033:anatomy & histology* / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005240:Feasibility Studies; D016018:Least-Squares Analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051379:Mice
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine