| Objective: To observe the change of regional cerebral blood flow (rCBF) in different region of interest (ROI) under quiet condition and performing hand motor condition with single photon emission tomography, elucidate the mechanism of the brain regions activated by simple hand motor (repetitive and sequential finger- to- thumb opposition movements in turn) and detect the role of active cortical areas by analyzing the difference of rCBF in different age groups. Material and Methods: 18 normal subjects were selected (including men 7, women 11) and divided into the young group (age from 24 to 35 years old) and the old group (age from 55 to 68 years old) accordingly to the age. Each subject was examined regional cerebral blood flow respectively under quiet condition and executing the hand motor task with 99mTc-ECD SPECT imaging. Every imaging was performed in the morning. Observe the way of every subject executing the hand motor and record the motor frequence and amplititude. Before the experiment, let the subjects exercised the motor task so that the they could execute the hand movement by the stable frequence and the biggest amplititude during the experiment. Before the imaging, the subjects entered into the darkroom and sit down quietly with closing eyes and using earplugs so as to avoid the sound and light stimulation. After 15 minutes, the subjects imaging under quiet condition were injected 99mTc-ECD into the vein quickly, then continued to keep quiet to image; the subjects imaging under executing hand task executed the hand motor for 5 minutes, then were injected 99mTc-ECD, and executed the hand motor for 5 minuts again, stopped the motor and kept quiet to image. Star the imaging postinjection in 20 minutes. The subject layed down on the imaging bed and the head was fixed, keeping no movement. The imaging was performed at GE SPECT/HiSpeed, matrix 64×64, pace 6°, flip angle 90°, slice thickness 7 mm, and an image was acquired in 30~40s. The axial, coronal and sagittal imaging were obtained by canthomeatal plane as baseline. Outline the ROI in each layer image, star from the left, and copy it to the right. We determined the features of the regions of interest by visual analysis of images of the tomographic slices, and by applying known functional anatomy of the motor system and data from an anatomical stereotaxic atlas. We measured the radioactivity count of the regions of interest, each pixel was 1.725×1.725mm2. Compute the average radioactivity count of each region of interest. We caculated the average radioactivity count of each pixel of all brain which was took as the reference. We caculated the radioactivity ratio of each region of interest, which was perfusion index (PI). We computed the average PI of each region of interest in every group under different condition. Use a paired student's t test to analyse the difference of PI of each region of interest under different condition. Results: About the hand movement, there was no significant difference on the frequence and amplititude between two groups, but the average motor speed in the old group was slower than that in the young group, but the mistake rate in the old group was significant higher than that in the young group. After executing hand motor, there were no significant changes of the rCBF in ROI of all brain lobes, but the rCBF in contralateral primary cortex motor areas (M1),ipsilateral cerebellum,bilateral supplementary motor areas (SMA) had changed apparently. Contrasted with the young group, the rCBF of contralateral primary cortex areas (M1),ipsilateral cerebellum in the old group was lower, and bilateral supplementary motor areas (SMA) higher. Discussion: The brain functional state and the age were two important factors influencing the cereal blood flow. 1. Movement will enhances the CBF. During the simple hand motor, the CBF in contralateral M1,ipsilateral cerebellum,bilateral SMA increased apparently. 2. In normal subjects, the CBF decreases with the age increasing. Therefore, the CBF of the activiated...
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