弥散张量成像定位初级运动功能区的研究

Functional identification of primary motor area by diffusion tensor imaging

目的 探讨弥散张量成像在定位初级运动功能区的价值.方法 20例脑深部肿瘤患者,分别进行常规MRI、fMRI及DTI检查,获取fMRI脑激活图、DTI图、3D解剖图.DTI通过三维重建皮质脊髓束定位初级运动功能区.fMRI采用手握拳激发模式,获取激活信号定位初级运动功能区.比较两种技术的吻合度,以评价DTI三维重建皮质脊髓束定位的初级运动功能区的准确性.结果 20例患者fMRI获得的激活信号主要位于对侧中央沟处,围绕着＂Ω＂形柄状结构分布,中央前回位于激活信号前方.所有患者均成功地完成DTI皮质脊髓束的三维重建,重建的皮质脊髓束也定位于激活信号前的脑回,两者均较好显示初级运动功能区且具有较好的一致性.结论 DTI可较好地定位初级运动功能区,这对于有肢体瘫痪患者及不能合作的儿童的初级运动功能区的定位有重要意义.

Objective To explore the usefulness of diffusion tensor imaging（DTI） in quick and stable identification of the primary motor area （ PMA）.Method 20 patients with deep-seated brain tumors underwent 3-dimensional T1-weighted imaging for anatomical reference,gradient-echo,echo-planar imaging（EPI） for functional magnetic resonance imaging （fMRI） and single-shot,diffusion-weighted EPI for diffusion tensor imaging（DTI）.The corticospinal tract （CST） was reconstructed by DTI.Motor activation signals were acquired by fMRI with hand clenching block active mode.Two techniques were compared to determine the accuracy for cortical mapping of PMA with CST in the 3D anatomic illustrations which fused the CST results and the fMRI activation signals.Results All of the patients performed fMRI motor activation task successfully.fMRI activation signals were distributed mainly in the contralateral central sulcus around the omega shape hand knob.The precentral gyrus was located in the former of the activation signals.CST was reconstructed successfuly in all patients which was located infront of the fMRI activation signals.There was a good consistency between CST and fMRI activation signals to identify PMA.Conclusions DTI enables identification of the PMA.Identifying PMA by CST is of great importance in patients who present with paralysis and the children who could not cooperation.