MR灌注成像在脑星形细胞瘤术前分级中的应用价值  

Evaluation of Perfusion MR Imaging in Preoperative Grading of Astrocytoma

作　　者：龙莉玲[1] 魏新华 黄仲奎[1] 李文美[1] 叶伟[1] 

机构地区：[1]广西医科大学第一附属医院放射科,南宁530021 [2]衡阳市中心医院放射科,研究生421001

出　　处：《临床放射学杂志》2004年第9期748-751,共4页Journal of Clinical Radiology

基　　金：广西自然科学基金资助项目 (桂科基 0 14 40 13 )

摘　　要：目的　评价MR灌注成像在脑星形细胞瘤术前分级中的应用价值。资料与方法　对 34例脑星形细胞瘤患者行常规MRI及MR灌注成像 ,所有病例分为 3组 :低级别星形细胞瘤 (LGA) 12例 ,间变性星形细胞瘤 (AA) 13例 ,胶质母细胞瘤 (GBM) 9例。灌注成像先得到信号强度 时间曲线 ,并合成局部脑血容量 (rCBV)图 ,计算相对局部脑血容量 (rrCBV)。计算出感兴趣区对比剂首过期末的信号下降百分率 ,作出对比剂平均通过时间 (MTT)图 ,得出MTT值 ,计算出微血管相对渗透值 (rP)。结果　LGA、AA及GBM最大rrCBV分别为 3.2 3± 0 .92 ,5 .0 5± 0 .6 6 ,5 .18± 0 .34;3组的微血管rP分别为 1.34± 0 .4 6 ,2 .17± 0 .2 8,2 .5 9± 0 .6 0。 3组间的rrCBV及rP值均有显著性差异 ,rP与rCBV有明显正相关 (r=0 .85 3,P <0 .0 1)。结论　MR灌注成像参数rrCBV、rP能在术前可靠地评价星形细胞瘤的病理级别。Objective To evaluate perfusion MRI in the preoperative assessment of histological grade in astrocytomas.Materials and Methods Both conventional and perfusion MRI were performed in 34 patients with pathologically confirmed astrocytoma. The lesions were divided into three groups: low-grade astrocytoma (LGA, n=12), anaplastic astrocytoma (AA, n=13) and glioblastoma (GBM, n=9). Perfusion MRI was carried out with a gradient-echo echo-planar T 2 *-weighted imaging sequence. The signal intensity-time curve was obtained, and the regional cerebral blood volume (rCBV) map was generated. Then, the maximal relative regional cerebral blood volume (rrCBV) was calculated. The signal reduction ratio and mean transit time (MTT), which was obtained from MTT map, were used to calculate the relative permeability (rP) of microvessel.Results The maximum rrCBV in LGA, AA and GBM was 3.23±0.92, 5.05±0.66 and 5.18±0.34, respectively. The maximum rP in LGA, AA and GBM was 1.34±0.26, 2.17±0.28 and 2.59±0.60, respectively. Significant difference in rrCBV and rP existed between each group. A marked positive correlation was seen between rP and rCBV (r=0.853).Conclusion MR perfusion parameters, rrCBV and rP, are very reliable index for preoperative estimating the histological grade of astrocytomas.

关 键 词：MR灌注成像 脑星形细胞瘤 术前 GBM 脑血容量 微血管 对比剂 可靠 信号强度 百分率 

分 类 号：R739.4[医药卫生—肿瘤]