BOLD contrast on a 3 T magnet: detectability of the motor areas.
To predict the potential and the limitations of functional MRI (fMRI) with a very high field magnet, the detectability and reproducibility of activation were evaluated by comparing the activation induced by a sequential finger movement task at 1.5 T with that at 3 T. The detectability of the premotor area, supplementary motor area (SMA), and ipsilateral sensorimotor area (SM1) showed significant improvement at 3 T. On the other hand, the detectability of contralateral SM1 was not significantly different between 1.5 and 3 T. The degree of activation was proportional to task demand in the ipsilateral SM1 and SMA, whereas that in the contralateral SM1 and SMA was not. FMRI with a 3 T magnet has greater potential for detection of neuronal activation as a functional network. These observations indicated that task demand and static magnetic field strength should be considered in interpretation of fMRI data for clinical usage.
Nakai
T
T
Magnetic Resonance Science Laboratory, Electrotec Laboratories, MITI, Osaka, Japan. nakai@etl.go.jp
Matsuo
K
K
Kato
C
C
Okada
T
T
Moriya
T
T
Isoda
H
H
Takehara
Y
Y
Sakahara
H
H
D000328:Adult; D000704:Analysis of Variance; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D005385:Fingers / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000098:blood supply / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric