كاربرد تكنيك تصويربرداري عملكردي رزونانس مغناطيسي جهت نمايش و بررسي الگوي فعاليت كورتكس حركتي مغز بهنگام انجام عمل فلكسيون-اكستاسيون مچ دست

Application of functional magnetic resonance imaging (fMRI) to display and evaluate brain motor cortex activity pattern during wrist flexion-extension task

Objective: This research has been conducted to detect and measured brain motor cortex activity of 25 normal volunteers during wrist flexion-extension task using optimized Gradient Echo-Planar Imaging (GR - EPI) technique by measuring blood oxygen level dependent changes in MR signal. Subjects and Methods: Scanning was performed on a 1.5 T General Electic MR Scanner (Signa Model) at Naft Grand Hospital. An optimized gradient echo T2*- weighted echo-planar sequence was used with the following parameters FOV = 24 cm, NEX = 1, TR = 2000ms,TE = 55 ms, Flip Angle = 900, Matrix Size = 128 * 128 and Thickness = 5 mm . One hundred and twenty axial images were acquired serially using a block design during rest and wrist flexion-extension task from the motor cortex area of the wrist around Sulcus of Rolando. Acquired images reformatted from DICOM Dicom to Analyze using MRIcro and underwent complex image processing and analysis using SPM2 and MATLAB (Ver. 7) Results: The results showed a significant increase (P≤0.05) in S signal intensity of brain motor cortex during the task in comparison with the rest state. Activated areas in brain cortex were shown as clusters of 153 to 185 pixels in size (165.12 ± 9.93). Conclusion: The findings of this study may be used to evaluate the changes of brain cortex activity in various diseases and also to assess the respond to treatment procedures.