磁共振灌注加权成像在胶质瘤术前分级中的应用研究

目的：通过磁共振灌注加权成像（PWI）研究肿瘤实性区域的微血管生成情况,探讨灌注加权成像在胶质瘤术前分级中的应用价值。方法：回顾性分析手术病理证实的脑胶质瘤患者常规MRI和PWI检查资料,按照2000年WHO脑肿瘤分级标准,低级别胶质瘤（Ⅰ～Ⅱ级）15例,高级别胶质瘤（Ⅲ～Ⅳ级）15例。在工作站构建rCBV图,分别测量肿瘤实性区域和相应部位正常参照区域的rCBV值,观察高级别胶质瘤组和低级别组肿瘤实性区域CBV值与正常对照的相互关系,并着重观察两组肿瘤各自与正常参照区域的相对（肿瘤/参照）CBV（rCBV）值之间的关系。低级别和高级别胶质瘤之间肿瘤实性区域rCBV值的比较采用两样本t检验,P〈0.05为有统计学差异,P〈0.01时有显著性差异。结果：高级别胶质瘤组rCBV值（4.14±0.85）明显高于后者（2.51±0.59）,两组之间差异有显著性（P〈0.01）。结论：高级别胶质瘤与低级别胶质瘤瘤体实性区域rCBV值有显著性差异,这提示MRPWI有助于提高胶质瘤术前分级评价准确性。

Diffusion MR Imaging for preoperative evaluation of tumor grade in Gliomas

Objective ：To retrospectively measure the perfusion-weighted imaging （PWI） characteristics of solid regions of gliomas,emphasizing on the role of PWI in preoperative evaluation of tumor grade in gliomas.Metbods：30 patients with pathology-proved gliomas（15 cases,WHO Ⅲ -Ⅳ,high-graded;WHO Ⅰ-Ⅱ ,lower-graded, 15 cases） were examined with PWI MR imaging. Cerebral blood volumes （CBV） were measured on maps generated from PWI data of solid regions of tumors, and analogous locations in the contralateral WM corresponding to these areas. Changes in CBV in each type of tissue were compared across tumor types by using a two-sample test. P〈0.05 indicated statistical significance.Results：For high-grade gliomas,the rCBV were 4.14 （SD=0.85） for high-grade gliomas and 2.51 （SD=0.59） for lower-grade group （P〈0.01）. Conclusion：The difference in rCBV in solid regions between high-grade gliomas and lower-grade gliomas was significant. These findings may indicate a role for perfusion MR imaging in the differentiation of high-grade gliomas and lower-grade on the basis of differences in perfusion levels in solid regions of tumors.