Functional MRI
The overall goal of this project is to investigatebrain function under acupuncture therapy as well as under motor,somatosensory, sound-listening, word-listening, and visual stimulationusing BOLD and perfusion MRI techniques.
(1) Supplemental motor cortex
Supplementary motor area (SMA) and premotorarea are known to be activated by the motor task in addition tothe primary motor area (M1). We studied whether the complex motortask elicits a greater activation of SMA than the simple motortask using functional magnetic resonance imaging (fMRI). We employedboth hand grasp as the simple motor task and finger oppositionas the complex motor task. During the simple motor task, the areaof activation was observed mainly in the contralateral M1. Incontrast, the complex motor task activated both the contralateralM1 and SMA. The complex motor task has a greater influence onthe activation of supplementary motor area than the simple motortask.
(Fukunaga M, et al Electroencephalography and Clinical Neurophysiology(suppl.) 47: 265-269, 1996)
(2) Perfusion weighted fMRI
Numerous studies to investigate brain activationhave been reported using a functional MRI (fMRI) technique basedon blood oxygenation level dependent (BOLD) effect, which is sensitiveto alterations in local deoxyhemoglobin content. Recently, flow-sensitivealternating inversion recovery (FAIR) sequence has been reportedfor semiquantitative measurements of cerebral blood flow. We comparedfMRI using FAIR with conventional fMRI based on BOLD. The BOLDimages were obtained by using single-shot gradient echo echo planarimaging (EPI) sequence. FAIR images were obtained by using single-shotinversion recovery EPI sequence. Photic stimulation was checkerpattern reversal at 4Hz for both visual field. On and off alternationduring 40s was sequentially continued 8 times. Data were analyzedon calculated cross correlation coefficient (CC) images usingMR Vision software (MR Vision Co.Ltd). Figure showed T1-weightedimage, original FAIR image, CC image based on BOLD and CC imagesbased on FAIR. The activated area in CC image based on FAIR wassmaller than that in CC image based on BOLD.
Last Updated by T.Ebisuon 5/01/98