DTI在颅内星形细胞瘤临床分级及外科手术中的应用价值研究

目的 探讨磁共振扩散张量成像(DTI)多参数综合分析及扩散张量纤维束成像(DTT)在星形细胞瘤临床分级中的应用价值.方法 收集经手术病理证实为星形细胞瘤的患者33例,术前均行常规T1WI、T2WI、T1wI增强、DTI检查,其中5例患者术后再次行常规T1WI、T2WI、增强扫描、DTI检查.测量病灶肿瘤实质区、瘤周水肿区、囊变坏死区、水肿临近正常白质区及对侧正常白质区的DCavg值、FA值、1-VR值及RA值,并进行统计分析,比较各个值在星形细胞瘤分级中的应用.利用DTI原始数据进行扩散张量纤维束成像(DTT)重建病变周围脑白质纤维柬.结果 FA图、FA彩色编码图、DTT图均能显示脑白质纤维受累情况,而常规MRI难以显示;各组中的肿瘤实质区、囊变坏死区、瘤周水肿区及水肿临近正常白质区的DCavg值、FA值、1-VR值及RA值均存在显著差异(P<0.05).低级别星形细胞瘤肿瘤周围的白质纤维束多呈推挤水肿改变,2例患者术后白质纤维束移位水肿减轻,预后良好,而高级别星形细胞瘤肿瘤周围的白质纤维束多表现为以浸润破坏为主,3例患者术后无改善.结论 结合常规MR图像,DCavg值、FA值、1-VR值及RA值均有助于区分肿瘤的实质区、囊变坏死区、水肿区及正常白质区;结合肿瘤实体、瘤周水肿区及水肿邻近正常自质区的FA值、1-VR值及RA值有助于低、高级别星形细胞瘤的鉴别;DTI及DTT可无创的显示脑白质纤维束的受累情况,显示重要的脑白质纤维束与脑肿瘤的位置关系,有助于患者术前计划的制定和手术效果的评价.

The clinical and surgical application study of DTI multiple parameter value in astrocytomas

Objective To.investigate the clinical usefulness of DTI multiple parameter and diffusion tenser tracting in astrocytomas.Methods Thirty-three cases of astrocytomas with pathologic confirmation underwent routine MRI,enhanced scanning and DTI before operation.Five cases underwent routine MRI,enhanced scanning and DTI again after operation.DCavg,FA,1-VR and RA values were measured in the solid part of tumors,the necrotic area,the peritumoral edema,the white matter area surrounding the edema and corresponding normal brain;and the white matter surrounding tumors were rebuilded with DTT.Results The white matter of brain could be seen better in FA and DTI gragh.and not in routine MRI.There was significant difference of DCavg,FA,1-VR and RA values in the solid part of tumors,the necrotic area,the peritumoral edema and the white matter area surrounding the edema.The peritumoral white matter of most low-grades astrocytomas cases were displaced,which of high-grade astrocytomas were destroyed.Conclusion Combined with conventional MR imaging,DCavg,FA,1-VR and RA values are conduced to distinguish the solid part of tumors,the necrotic area,the peritumoral edema and the white matter area surrounding the edema in distinguishing astrocytomas grade;FA value,1-VR value,and RA value are conduced to detected low-grade and high-grade astrocytomas.DTI and DTT can be used to select the better opration methods and evaluate effect of opration.