In vivo 1H NMR spectroscopy of the human brain at 9.4 T: initial results.
In vivo proton NMR spectroscopy allows non-invasive detection and quantification of a wide range of biochemical compounds in the brain. Higher field strength is generally considered advantageous for spectroscopy due to increased signal-to-noise and increased spectral dispersion. So far (1)H NMR spectra have been reported in the human brain up to 7 T. In this study we show that excellent quality short echo time STEAM and LASER (1)H NMR spectra can be measured in the human brain at 9.4 T. The information content of the human brain spectra appears very similar to that measured in the past decade in rodent brains at the same field strength, in spite of broader linewidth in human brain. Compared to lower fields, the T(1) relaxation times of metabolites were slightly longer while T(2) relaxation values of metabolites were shorter (<100 ms) at 9.4 T. The linewidth of the total creatine (tCr) resonance at 3.03 ppm increased linearly with magnetic field (1.35 Hz/T from 1.5 T to 9.4 T), with a minimum achievable tCr linewidth of around 12.5 Hz at 9.4 T. At very high field, B(0) microsusceptibility effects are the main contributor to the minimum achievable linewidth.
Deelchand
Dinesh Kumar
DK
Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA. dinesh@cmrr.umn.edu
Van de Moortele
Pierre-François
PF
Adriany
Gregor
G
Iltis
Isabelle
I
Andersen
Peter
P
Strupp
John P
JP
Vaughan
J Thomas
JT
Uğurbil
Kâmil
K
Henry
Pierre-Gilles
PG
D000328:Adult; D000818:Animals; D001923:Brain Chemistry; D003401:Creatine / Q000032:analysis; D004574:Electromagnetic Fields; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D009778:Occipital Lobe / Q000737:chemistry; D051381:Rats; D055815:Young Adult
D003401:Creatine