扩散张量成像及扩散张量纤维束成像在星形细胞瘤与脑膜瘤诊断中的价值

目的 探讨DTI及扩散张量纤维束成像(DTT)诊断星形细胞瘤与脑膜瘤的价值。方法 对22例经病理证实的脑肿瘤患者(不同级别星形细胞瘤12例,良性脑膜瘤10例),测量肿瘤实质区与健侧正常脑组织的平均ADC值和FA值,比较测值,并观察两种脑肿瘤对白质纤维束的影响。结果 星形细胞瘤及脑膜瘤患者肿瘤实质区FA值均较健侧正常脑组织降低(P均<0.05);星形细胞瘤患者肿瘤实质区ADC值较健侧正常脑组织高(P<0.05),脑膜瘤患者肿瘤实质区ADC值与健侧正常脑组织差异无统计学意义(P>0.05)。星形细胞瘤与脑膜瘤患者比较,肿瘤实质区ADC值、FA值差异有统计学意义(P均<0.05)。在DTT图中,星形细胞瘤多数表现为纤维束部分中断、受压、偏移或变形、移位;脑膜瘤纤维束呈现为稀疏、移位。结论 测量肿瘤实质区ADC值和FA值可鉴别脑内和脑外肿瘤如星形细胞瘤与脑膜瘤。DTT可清晰显示脑肿瘤对白质纤维束浸润、破坏和推移,有利于术前制定手术方案。

Value of diffusion tensor imaging and diffusion tensor tractography in diagnosis of astrocytoma and meningioma

Objective To observe the value of DTI and diffusion tensor tractography (DTT) in diagnosis and differential diagnosis of astrocytoma and meningioma. Methods Twenty-two patients with pathologically proven brain tumor (12 different grade astrocytomas, 10 benign meningiomas) were enrolled. ADC value and FA value in the tumor parenchyma and corresponding contralateral normal brain tissue were measured and analyzed. Impact of the two kinds of tumors on cerebral white matter fiber bundles were observed. Results Compared with the contralateral normal brain tissue, FA values of parenchyma of astrocytoma and meningioma were lower (all P<0.05). ADC values of parenchyma of astrocytoma were higher than normal brain tissue (P<0.05), while of meningiomas were not significantly different (P>0.05) compared with the contralateral normal part. ADC and FA values were significantly different between parenchyma of astrocytoma and meningioma (all P<0.05). On DTT, astrocytoma showed partial disruption, compression, deviation and displacement fiber bundles, while meningioma showed significant rarefaction and displacement fiber bundles. Conclusion Measurement of tumor parenchyma's ADC values and FA values can be used to identify intra-cerebral and extra-cerebral tumors like astrocytoma and meningioma. DTT can clearly show the normal white matter fiber tracts and tumor anatomy, therefore it is conducive to the development of preoperative program.