弥散张量纤维束示踪成像在涉及锥体束脑肿瘤中的应用

目的探讨磁共振弥散张量纤维束示踪成像在涉及锥体束的脑肿瘤的术前计划和预测临床预后中的应用价值.方法对36例涉及锥体束的脑胶质瘤患者,术前在常规成像基础上,行弥散张量成像(DTI)序列检查采集全脑DTI原始数据,经工作站生成二维的部分各向异性伪彩图(FA color)和三维的锥体束白质纤维束示踪图,提供锥体束与脑内肿瘤的位置关系信息,优化手术方案,保护皮层下重要功能的白质纤维束,并预测患者预后.术前、术后行KPS评分,评价患者的生活状态.结果所有病人术前DTI图像采集经后处理均生成二维FA color图和三维锥体束白质纤维束示踪图.术前成功地显示出锥体束与脑内肿瘤的位置关系以及肿瘤对锥体束的影响,优化手术方案.36例病人中,20例DTI清楚显示肿瘤未累及锥体束,低级别16例、高级别4例,术前、后KPS评分平均为86和93;12例DTI显示肿瘤紧邻锥体束并推移,低级别6例、高级别6例,术前、后KPS评分平均为80和94;4例DTI显示肿瘤在大体上已浸润及/或破坏锥体束,低级别2例、高级别2例,术前、后KPS评分为67和80.结论在常规的MR成像后行弥散张量纤维束示踪成像研究,优化涉及重要白质纤维束如锥体束的脑肿瘤切除术的手术方案,保护皮质下重要功能的白质纤维,并可预测患者临床功能预后.

Diffusion tensor tractography in patients with brain gliomas involving pyramidal tracts: clinical application and outcome

Objective To explore the role of diffusion tensor tractography (DTT) in presurgical planning, and to predict the functional outcome of the patients with brain gliomas involving pyramidal tracts. Methods Thirty-six patients with brain gliomas involving pyramidal tracts were included. They underwent MR examination, which included conventional T1WI, T2WI and diffusion tenor imaging (DTI). The data of DTI were transferred to the workstation and analyzed. Fractional anisotropy (FA) color and three-dimensional pyramidal tracts were produced. The relationship between the white matters and tumors was demonstrated, which was used to optimize the pre-surgical planning, protect the subcortical important white matters, and predict the clinical outcome. The preoperative and postoperative KPS were respectively acquired to evaluate the condition of patients. Results The FA color mappings and 3D pyramidal tracts tractography were obtained. The relationship between them was successfully demonstrated to optimize the presurgical planning. In 20 patients, including 16 of low-grade glioma (LGG), 4 of high-grade glioma (HGG), DTI clearly demonstrated that pyramidal tracts were not involved by tumor. The pre-KPS and post-KPS were 86 and 93, respectively. In 12 patients, including 6 of LGG, 6 of HGG, DTI showed that pyramidal tracts were close to tumor and displaced. The pre-KPS and post-KPS were 80 and 94, respectively. In 4 patients, including 2 of LGG, 2 of HGG, DTI suggested that pyramidal tracts were invaded and disrupted by tumor. The pre-KPS and post-KPS are 67 and 80, respectively. Obviously, compared to the preoperative KPS, the postoperative KPS were nearly improved. Conclusion DTT allows individual estimation of the relationship between important white matters such as pyramidal tracts and brain gliomas, which should be used to plan the optimal trajectory and protect vital white matters, and predict patients' clinical outcome.