弥漫性胶质瘤3.0T磁共振扩散张量成像及纤维束成像的初步研究  

Preliminary study of diffusion tensor imaging and fiber tractography in diffuse gliomas at 3.0T MRI

作　　者：陆虹[1] 马林[2] 徐贤[2] 邹智彤[2] 程流泉[2] 

机构地区：[1]解放军307医院放射科,北京100071 [2]解放军总医院放射诊断科,北京100853

出　　处：《中国医学影像技术》2007年第8期1139-1142,共4页Chinese Journal of Medical Imaging Technology

摘　　要：目的探讨扩散张量成像（DTI）及纤维束成像在弥漫性胶质瘤的诊断、分级以及显示肿瘤与周围结构关系等方面的作用。方法使用3.0T磁共振ASSET-SE-EPI序列对37例弥漫性胶质瘤患者（WHO分级：Ⅱ级16例,Ⅲ级11例,Ⅳ级10例）进行DTI成像。分别测定病灶实性部分、灶周水肿区、病灶及水肿周围T2WI显示信号正常区域、病灶同侧远处T2WI显示信号正常区域及对侧大脑半球相对应区域的MD值和FA值。对灶周白质纤维束进行三维纤维束成像。结果肿瘤及瘤周水肿区的MD值明显高于对侧正常脑实质（P〈0.01）,而FA值则均明显低于对侧正常脑实质（P〈0.01）。Ⅱ级肿瘤内的FA值明显低于Ⅲ级和Ⅳ级（PⅡ-Ⅲ=0.024;PⅡ-Ⅳ=0.030）。各级别胶质瘤肿瘤内与瘤周水肿区之间的MD值和FA值均无统计学差异（P〉0.05）。三维纤维束成像显示,Ⅱ级胶质瘤对周围白质纤维束主要是推移;Ⅲ级胶质瘤周围水肿区均可见纤维束较明显的破坏,肿瘤周围T2WI信号正常白质区内也有部分纤维束被肿瘤浸润甚至破坏;Ⅳ级胶质瘤周围水肿区及T2WI信号正常白质区内均有明显的纤维束浸润、破坏。结论各级别弥漫性胶质瘤瘤周白质纤维束均有不同程度的浸润破坏,反映了弥漫性胶质瘤浸润性生长的特征。MD值和FA值可用于区分胶质瘤与正常脑组织。FA值可用于区分低级别胶质瘤与高级别胶质瘤。DTI方向编码彩图和三维纤维束成像可以清楚、直观地显示肿瘤与周围白质纤维束的关系。　Objective To evaluate the efficacy of ASSET-DTI and tractography in diagnosing and grading of diffuse gliomas, and in displaying the relationship between the tumors and surrounding structures. Methods DTI scans were performed in 37 patients with diffuse gliomas （WHO grade： grade Ⅱ16 cases, grade Ⅲ 11 cases, and grade Ⅳ 10 cases）by using ASSET-SE-EPI sequence on 3.0T MR scanner. MD and FA values were measured in the solid portion of the tumor, in the peritumoral edema, in normal-appearing white matter （NWM） on T2WI surrounding the tumor and edema, in distant NWM on T2WI ipsilateral to the tumor, and in the corresponding region on contralateral side, respectively. Three dimensional tractography of peritumoral fiber tracts was performed with FuncTool software. Results In the tumor and peritumoral edema, MD values were significantly higher and FA values were significantly lower than those in the contralateral regions （P〈0.01）. The intratumoral FA value of grade Ⅱ glioma was significantly lower than those of grade Ⅲ and Ⅳ （PⅡ-Ⅲ=0.024, PⅡ-Ⅳ=0.030）. The intratumoral and peritumoral edematous MD values of grade Ⅱ glioma were higher than those of grade Ⅲ and Ⅳ, but the differences were not significant （P〉0.05）. MD and FA values between tumor and peritumoral edema showed no differences in all tumors （P〉0.05）. The tractography showed that the main influence of grade Ⅱ glioma on adjacent white matter tracts was displacement, but infiltration and destruction were also revealed. The destruction of fiber tracts could be seen in all edema regions around grade Ⅲ gliomas, and invasion or even destruction of fiber tracts could be seen in some NWM regions. The destruction of fiber tracts was clearly demonstrated in both edema and NWM regions around grade Ⅳ gliomas. Conclusion Infiltration and destruction of the peritumoral white matter tracts can be seen in diffuse gliomas with various grades, reflecting the characteristic infiltrative growth pattern of this kind of

关 键 词：弥漫性胶质瘤 扩散张量成像 纤维束成像 平均扩散率 部分各向异性 

分 类 号：R739.41[医药卫生—肿瘤] R445.2[医药卫生—临床医学]