论文部分内容阅读
[目的]应用磁共振弥散张量成像(DTI)技术探讨脑星形细胞瘤近瘤周白质区DTI征象,以及不同级别星形细胞瘤近瘤周区(IPR)平均弥散系数(MD)值、各向异性分数(FA)值改变的意义。[方法]48例脑星形细胞瘤术前行DTI扫描,重建FA图,评价FA图像中IPR的信号特点,并测定IPR及对侧正常脑白质区的MD值及FA值,计算相对MD(rMD)和相对FA值(rFA)。[结果]星形细胞瘤IPR白质区的FA图及彩色FA图能显示出白质纤维各向异性降低和走形方向的改变。星形细胞瘤IPR白质区MD值高于对侧正常脑白质组(t=11.423,P<0.001);除Ⅱ级与Ⅲ级星形细胞瘤组间MD值和rMD无统计学差异外,其余级别星形细胞瘤组间MD值和rMD均有统计学差异(P<0.05)。星形细胞瘤IPR白质FA值低于对侧正常脑白质组(t=-22.611,P<0.001);Ⅲ~Ⅳ级星形细胞瘤IPR白质的FA值、rFA降低,明显低于Ⅰ~Ⅱ级星形细胞瘤组(P<0.05)。[结论 ]FA图及彩色FA图能较为直观准确地反映IPR白质受肿瘤侵犯的情况;MD值、FA值能够一定程度定量反映不同级别星形细胞瘤对IPR造成的病理影响。
[Objective] To investigate the DTI signs of near-tumor white matter in astrocytomas and the average diffusivity (MD) value of the astrocytomas near the peritumoral region (IPR) using magnetic resonance diffusion tensor imaging (DTI) The significance of changing the value of anisotropy fraction (FA). [Methods] Forty-eight patients with brain astrocytoma underwent preoperative DTI scan and reconstruction of FA images to evaluate the signal characteristics of IPR in FA images. The MD and FA values of IPR and contralateral normal white matter were measured, and the relative MD rMD) and relative FA value (rFA). [Results] The FA maps and the color FA maps of astrocytomas in IPR white matter region showed the decrease of anisotropy of white matter fibers and the change of the direction of migration. The MD value of white matter of IPR in astrocytomas was higher than that in contralateral normal white matter (t = 11.423, P <0.001). There was no significant difference in MD and rMD among grade Ⅱ and Ⅲ astrocytomas The level of astrocytomas MD values and rMD were statistically significant (P <0.05). The FA value of IPR white matter in astrocytoma was lower than that in contralateral normal white matter group (t = -22.611, P <0.001). The FA value and rFA of IPR white matter in grade Ⅲ ~ Ⅳ astrocytomas were significantly lower than those in Ⅰ ~ Ⅱ Grade astrocytoma group (P <0.05). [Conclusion] The FA and color FA maps can reflect the invasion of IPR white matter more accurately and accurately. The MD and FA values can quantitatively reflect the pathological effects of different grades of astrocytomas on IPR.