基于组织相似度图谱的MR灌注成像评价脑胶质瘤的价值探讨

Value of Tissue Similarity Maps( TSM) Based Relative Cerebral Blood Volume( rCBV) in Evaluation of Gliomas

目的探讨基于组织相似度图谱(TSM)MR灌注成像(PWI)评价脑胶质瘤血流灌注情况的可行性及在胶质瘤分级中的价值。方法搜集经手术病理证实的24例脑肿瘤(Ⅱ级9例,Ⅲ级8例,Ⅳ级7例)患者的MR常规及灌注成像资料。经TSM算法软件和MRI工作站PWI后处理软件将扫描数据进行处理,得到TSM图和脑血容量(CBV)图。分别测算肿瘤实质区和正常脑白质区(WM)的CBV_(PWI)值或CBV_(TSM)值,然后计算出脑胶质瘤的r CBV_(PWI)值、r CBV_(TSM)值,并分别对Ⅱ级、Ⅲ级、Ⅳ级胶质瘤r CBV_(PWI)值和r CBV_(TSM)值进行统计学分析。结果 (1)Ⅱ级、Ⅲ级和Ⅳ级胶质瘤的r CBV_(PWI)值和r CBV_(TSM)值之间差异均无统计学意义。(2)Ⅱ级胶质瘤的r CBV_(PWI)值(1.83±0.48)显著低于Ⅲ级(5.95±2.52)(P=0.002)和Ⅳ级(6.47±2.30)(P=0.001)。Ⅲ级和Ⅳ级之间差异无统计学意义(P=0.631)。同样,Ⅱ级胶质瘤的CBV_(TSM)值(2.18±0.38)显著低于Ⅲ级(6.06±2.81)(P=0.007)和Ⅳ级(6.27±2.76)(P=0.006)。Ⅲ级和Ⅳ级之间差异无统计学意义(P=0.87)。结论基于TSM的MR灌注成像可用于评价脑胶质瘤的血流动力学变化,并能于术前对胶质瘤进行分级诊断。

Objective To investigate the feasibility of tissue similarity map （TSM） based relative cerebral blood vol- ume （rCBV） in evaluation of the hemodynamic characteristics as well as the value in preoperative assessment of histologic grading of gliomas.. Methods 24 patients with gliomas （9 low-grade and 15 high-grade, according to WHO criteria） were examined with conventional MR and MR perfusion imaging preoperatively. The scanning data were operated by MAT- LAB7.6 software for TSM map and MR workstation for CBV map respectively. The CBVTsn and CBVpwI of tumor parenchy- ma and normal brain white matter were then measured respectively. The rCBVTSM and rCBVpwI were calculated and com- pared. Results （ 1 ） There were no statistical differences when the rCBVpwI and rCBVTsM of grades Ⅱ or grades Ⅲ or grades 1V were compared. （2） The rCBVpwI of grade 11 gliomas （1.83±0.48） were significantly lower than that of grade m 〈5 95±2 52） （ P = 0. 002） and grade Ⅳ（6.47 ± 2.30） （ P = 0. 001 ） gliomas. There was no statistical difference when grades HI and IV gliomas were compared （P =0.631 ）. Similarly, The rCBVTsM of grade Ⅱ gliomas （2.18±0.38） were significantly lower than that of gradeⅢ （6.06±2.81 ） （ P = 0. 007 ） or grade Ⅳ （ 6.27±2.76 ） （ P = 0. 006 ） gliomas. There was no statistical difference when grades m and IV gliomas were compared （P = 0.87）. Conclusion TSM based MR perfusion imaging can be used to evaluate the hemodynamic changes of gliomas, and it is expected to provide a new means in preoperative assessment of histologic grading of gliomas.