The Clinical Application of Functional Magnetic Resonance Imaging in Ischemic Stroke – Final Repor t

The three-year research project intended to develop new techniques of functional magnetic resonance imaging (fMRI) and its clinical application on ischemic stroke in three different stages. In our first yea plan, we collected the normal data of fMRI from visual and motor stimulations. In the second year, we collect data from patients with ischemic brain infarcts. In the last year we emphasizing the influence of time factor after the stroke episode. The basic principle of our experiment is so called “blood oxygen level dependent” (BOLD) effect. The experiment was implemented on a clinical machine of 1.5 T GE Signa and Siemens Magneton (with EPI). The pulse sequence for imaging acquisition was T2WI such as “FLASH” in gradient echo or EPI. The experiment was carried out with the finger tapping movement and 8-Hz flash light visual stimulation in normal subjects. The functional images first went through the post- processing of correlation coefficient. Those pixels highly correlated (p < 0.001) with an assumed input function were mapped back on to structure images. Further quantitation was perfomed on signal intensity and relative index of regional of interest (ROI ). The analysis showed in the acute stage, the response on the lesion side was weaker than the sound side. However, in the chronic stage the response being more complicated and worth further study