Abstract
Purpose: To determine the functional brain localization of the eye tracking test (ETT), we studied healthy volunteers by functional magnetic resonance imaging (fMRI). Methods and Materials: Three healthy volunteers underwent examinations using our 1.5 Tesla Magnetic Resonance Imager (Signa 1.5) under one shot echoplanar imaging (EPI) sequence (TR 4000 msec, TE 60 msec, FOV 24 cm, 8 mm thickness, 64 X 64 matrices, and horizontal slices). These images were analyzed by T test using "STIMULATE". The results were superimposed on three-dimensional brain surface images of themselves. The task was saccadic and smooth pursuit. The ETT target was projected from the operating room to a translucent screen in the scanning room. Results and Discussion: The frontal eye field, the associative visual cortex, and the lateral occipito-temporal cortex were well detected. In our study, the frontal eye field included Brodmann areas 4 and 6, but not 8. In all cases, saccadic and smooth pursuit showed similar activated patterns. However, the latter showed higher statistical confidence. Cerebellar activation was also detected, but the interslice gaps may have be too wide to detect the localization. Half coronal gapless thin slices should be employed for cerebellar analysis. Conclusion: FMRI is a very powerful method to analyze the brain localization of the ETT.
