High field localized proton spectroscopy in small volumes: greatly improved localization and shimming using shielded strong gradients.
The availability of shielded gradients facilitates accurate single-voxel spectroscopy. Exact localization (90-99%) of volumes as small as 2 x 2 x 2 mm is demonstrated using a modified stimulated echo sequence. Strong gradient pulses (up to 200 mT/m) are employed to clear the stimulated echo of unwanted magnetization, enabling superior (single-scan) shimming of the selected volume. In vivo and in vitro proton NMR results at 4.7 T are presented.
van Zijl
P C
PC
Clinical Pharmacology Branch, NCI, National Institutes of Health, Bethesda, Maryland.
Moonen
C T
CT
Alger
J R
JR
Cohen
J S
JS
Chesnick
S A
SA
D000818:Animals; D001923:Brain Chemistry; D002415:Cats; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons
D011522:Protons