三维准连续动脉自旋标记灌注成像对WHO Ⅱ级胶质瘤分型临床应用价值初探

A preliminary study of 3-dimensional pseudocontinous arterial spin labeling in WHO grade Ⅱ gliomas subtyping

目的胶质瘤的不同病理类型预示着不同的预后和对治疗的不同反应。通过比较WHOⅡ级胶质瘤不同病理类型肿瘤最大血流量与对侧正常白质血流量比值(nCBF)的差异,回顾性分析三维准连续动脉自旋标记(3D-PCASL)灌注成像在WHOⅡ级胶质瘤各种病理类型鉴别诊断中的价值。材料与方法 34例经病理证实的WHOⅡ级胶质瘤患者术前行常规MR平扫、3D-PCASL、常规增强扫描。运用后处理图像,根据CBF图,术后测量肿瘤区最大CBF值及对侧正常白质区CBF值并求比值(nCBF),按照病理结果分星形细胞瘤(16例)、少突胶质细胞瘤(13例)和少突星形细胞瘤组(5例)进行nCBF各组间的统计学分析。结果星形细胞瘤平均nCBF值(1.213±0.506)稍低于少突胶质细胞瘤组(1.283±1.414),差异没有明显统计学意义(P=0.855)。少突星形细胞瘤由于病例数太少,未纳入统计学分析。结论 WHOⅡ级胶质瘤的不同病理类型其灌注值没有明显差异,3D-PCASL在WHOⅡ级胶质瘤病理分型中鉴别诊断的临床意义还有待于进一步研究证实。

Objective：Different subtypes of gliomas present different prognosis and different response to therapy. To retrospectively analyses the differentiating diagnostic accuracy of 3-dimensional pseudocontinous arterial spin labeling （3D-PCASL） in the prediction of WHO grade II gliomas subtyping, and to appraise normalized lesion/normal tissue cerebral blood flow （nCBF） with histological findings as a reference standard. Materials and Methods：34 patients with pathologically proved WHO grade II gliomas underwent conventional magnetic resonance sequences, 3-dimensional pseudocontinuous arterial spin labeling （3D-PCASL） and post-contrast MR imaging. Representative maximal nCBF originated from 3D-PCASL regions of interest were chosen and measured from each lesion. These parameters were used for statistical evaluation according to histopathological result to group astrocytomas （n=16）, oligodendrogliomas （n=13） and oligoastrocytomas （n=5）. Results：The mean nCBF ratio （1.213±0.506） of astrocytomas was slightly lower than that （1.283±1.414） of oligodendragliomas group. There was no signiifcant difference between both groups for mean nCBF ratio （P=0.854）. Without enough sample of oligoastrocytoma group, it was excluded for statistic analysis. Conclusions：There was no obvious difference in perfusion between the different subtypes of WHO grade II gliomas. It should be too early to say that 3D-PCASL is a valuable method for differentiating diagnosis different subtypes of WHO grade II gliomas which will be elucidated in further study.