脑星形细胞瘤近瘤周远瘤周白质区的扩散张量成像参数分析

DTI analysis of immediate and distant peritumoral regions in brain astrocytoma

目的旨在探讨脑星形细胞瘤近瘤周、远瘤周白质区的扩散张量成像(DTI)特征。方法 37例脑星形细胞瘤术前行DTI扫描,其中Ⅰ级6例,Ⅱ级12例,Ⅲ级10例,Ⅳ级9例。重建FA图和FA编码彩色图,评价FA图像中近瘤周(IPR)白质、远瘤周(DPR)白质及对侧正常脑白质区的信号特点,并测定相应平均称散率(MD)值及各向异性分数(FA)值。结果Ⅳ级星形细胞瘤IPR白质的MD值高于其他三组(P<0.05),Ⅲ级星形细胞瘤IPR白质的FA值低于Ⅰ、Ⅱ级星形细胞瘤组(P<0.05)。Ⅳ级星形细胞瘤IPR、DPR的白质FA值低于Ⅰ、Ⅱ、Ⅲ级星形细胞瘤组(P<0.05)。结论 DTI能够较为直观的、准确地反映IPR及DPR白质区受肿瘤侵犯的情况。

Objective To investigate the DTI features of white matters at immediate and distance peritumoral regions in brain astrocytoma. Methods 37 patients with brain astrocytoma received pre-surgical DTI scanning. A- mong them, there were 6 cases of grade Ⅰ, 12 of grade Ⅱ, 10 of grade Ⅲ and 9 of grade Ⅳ tumor. FA maps and col- or-coded FA maps were reconstructed. White matters at immediate peritumoral region （IPR）, distance peritumoral re- gion （DPR） and normal contralateral regions were evaluated for signal features and measured for MD and FA values. Results The IPR MD value of grade Ⅳ astrocytoma was remarkably higher than those of tumor with other 3 grades （P〈 0.05）; the IPR FA value of grade Ⅲ astrocytoma was lower that those of grades Ⅰ and Ⅱ tumors （P〈0.05）; and the IPR and DPR FA values of grade Ⅳ astrocytoma were significantly lower than those of grades Ⅰ,Ⅱ and Ⅲ tumors （P〈0.05）. Conclusion DTI provides intuitive and accurate visualization of tumor invasion at IPR and DPR.