In vivo 31P magnetic resonance spectroscopy of human brain at 7 T: an initial experience.
In vivo (31)P spectra were acquired from the human primary visual cortex at 7 T. The relaxation times of the cerebral metabolites, intracellular pH, rate constant (k(f)) of the creatine kinase (CK) reaction, and nuclear Overhauser enhancement (NOE) on the detected phosphorus moieties from irradiation of the water spins were measured from normal subjects. With a 5-cm-diameter surface coil, 3D (31)P chemical shift imaging was performed with a spatial resolution of 7.5 ml and an acquisition resolution of 8 min, resulting in a signal-to-noise ratio (SNR) for phosphocreatine (PCr) resonance of 32. The apparent T(1) and T(2) of PCr measured at 7 T were 3.37 +/- 0.29 s and 132.0 +/- 12.8 ms, respectively, which were considerably longer than those of adenosine triphosphate (ATP) (T(1): 1.02-1.27 s; T(2): 25-26 ms). The NOE measured in this study was 24.3% +/- 1.6% for PCr, and 10% for ATP. The k(f) measured in the human primary visual cortex was 0.24 +/- 0.03 s(-1). The results from this study suggest that ultra-high-field strength is advantageous for performing in vivo (31)P magnetic resonance spectroscopy (MRS) in the human brain.
Lei
Hao
H
Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Zhu
Xiao-Hong
XH
Zhang
Xiao-Liang
XL
Ugurbil
Kamil
K
Chen
Wei
W
D000255:Adenosine Triphosphate / Q000032:analysis; D000328:Adult; D003402:Creatine Kinase / Q000032:analysis; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010713:Phosphatidylcholines / Q000032:analysis; D010714:Phosphatidylethanolamines / Q000032:analysis; D010725:Phosphocreatine / Q000032:analysis; D012016:Reference Values; D014793:Visual Cortex / Q000737:chemistry*
D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010725:Phosphocreatine; C002449:glycerophosphoethanolamine; D000255:Adenosine Triphosphate; D003402:Creatine Kinase