多层螺旋CT灌注成像对星形细胞肿瘤分级的准确性评价

目的 评价多层螺旋CT灌注成像(CTP)参数对星形细胞肿瘤分级的敏感性和特异性.方法 对第三军医大学第三附属医院野战外科研究所收治的53例脑肿瘤患者进行CTP检查,经手术和病理学证实为星形细胞肿瘤的30例患者纳入研究对象.CTP采用GE LightSpeed 64层螺旋CT机行灌注扫描,在AW4.2P后处理工作站对原始数据进行后处理,测定肿瘤最大灌注区和对侧正常组织的脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)及毛细血管表面通透性(PS).手术获取脑肿瘤标本进行组织病理学检查.结果 星形细胞肿瘤高级别组CBF、CBV和PS值均明显高于低级别组,差异有统计学意义(P<0.05),MTT值比较差异无统计学意义(P>0.05).受试者工作特征曲线(ROC曲线)分析表明,CBF、CBV和PS值对鉴别高、低级别星形细胞肿瘤的ROC曲线下面积分别为0.914、0.876和0.914,而MTT无鉴别作用,其ROC曲线下面积为0.455.采用CBF=62.635 mL/(100 g·min),CBV=4.310 mL/100 g和PS=5.925 mL/(100 g·min)作为分界点鉴别高、低级别星形细胞肿瘤的敏感性均为84.2%,特异性分别是81.8%、81.8%和91.9%.结论 多层螺旋CTP参数CBF、CBV及PS值对鉴别高、低级别星形细胞肿瘤具有较高敏感性和特异性.

Accuracy of MSCT perfusion imaging in grading the astrocytic tumors

Objective To evaluate the sensitivity and specificity of CT perfusion(CTP)parameters in grading the astrocytic tumors.Methods Fifty-three patients with brain tumors underwent CTP examination,and the astrocytie tumors confirmed by operation and pathology(n=30)were selected and divided into high-grade group(n=19)and low-grade group(n=11).Perfusion scanning on the brain was performed by 64-slice spiral CT angiography and the data were analyzed by AW 4.2P software.Cerebral blood flow(CBF),cerebral blood volume(CBV),mean transit time(MTT)and permeability surface(PS)on the maximum perfusion area and the normal brain tissues in the opposite side were measured.Results High-grade group showed significantly higher CBF,CBV and PS values as compared with the low-grade group(P<0.05).However,the MTT values was not significantly different between the 2 groups(P>0.05).The under-ROC curve areas of the CBF,CBV and PS values between these 2 groups were 0.914,0.876 and 0.914,respectively;while that of MTT was only 0.455 and could not help differentiating the diagnosis.When the optimal limit values of these indicators for differentiation specificity was 81.8%,81.8% and 91.9%,respectively.Conclusion The CBF,CBV and PS values of multi-slice CTP show high sensitivity and specificity in differentiating the diagnosis of high-and low-grade astroeytic tumors.