3D 1H MRSI of brain tumors at 3.0 Tesla using an eight-channel phased-array head coil.
OBJECTIVE
To implement proton magnetic resonance spectroscopic imaging (1H MRSI) at 3 Tesla (3T) using an eight-channel phased-array head coil in a population of brain-tumor patients.


METHODS
A total of 49 MRI/MRSI examinations were performed on seven volunteers and 34 patients on a 3T GE Signa EXCITE scanner using body coil excitation and reception with an eight-channel phased-array head coil. 1H MRSI was acquired using point-resolved spectroscopy (PRESS) volume selection and three-dimensional (3D) phase encoding using a 144-msec echo time (TE).


RESULTS
The mean choline to N-acetyl aspartate ratio (Cho/NAA) was similar within regions of normal-appearing white matter (NAWM) in volunteers (0.5 +/- 0.04) and patients (0.6 +/- 0.1, P = 0.15). This ratio was significantly higher in regions of T2-hyperintensity lesion (T2L) relative to NAWM for patients (1.4 +/- 0.7, P = 0.001). The differences between metabolite intensities in lesions and NAWM were similar, but there was an increase in SNR of 1.95 when an eight-channel head coil was used at 3T vs. previous results at 1.5T.


CONCLUSIONS
The realized increase in SNR means that clinically relevant data can be obtained in five to 10 minutes at 3T and used to predict the spatial extent of tumor in a manner similar to that previously used to acquire 1.5T data in 17 minutes.
UCSF/UCB Joint Graduate Group in Bioengineering, University of California-San Francisco, San Francisco, California 94158-2532, USA. josorio@mrsc.ucsf.edu
Joseph A
JA
Osorio
Esin
E
Ozturk-Isik
Duan
D
Xu
Soonmee
S
Cha
Susan
S
Chang
Mitchel S
MS
Berger
Daniel B
DB
Vigneron
Sarah J
SJ
Nelson
D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007773:Lactates / Q000378:metabolism; D008055:Lipids / Q000032:analysis; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D013997:Time Factors
D007773:Lactates; D008055:Lipids; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline