磁共振灌注成像鉴别诊断高级别脑胶质瘤复发与假性进展

MR perfusion weighted imaging in discrimination between the recurrence and pseudoprogression in high-grade brain glioma

目的探讨磁共振灌注成像(magnetic resonance perfusion weighted imaging,MR-PWI)鉴别诊断高级别脑胶质瘤综合治疗后复发与假性进展的价值。方法纳入56例经手术切除后行术后同步放化疗的高级别脑胶质瘤患者,在MRI复查时行3.0T MR-PWI及常规T1加权增强(T1-weighted imaging,T1WI)检查,对术区新强化病灶行相对脑血容量(relative cerebral blood volume,rCBV)值的灌注分析,并行立体定向活检进行病理诊断。使用ROC评估rCBV值在鉴别诊断高级别脑胶质瘤复发与假性进展中的最佳临界值、敏感性和特异性。结果 56例患者,经病理证实30例为胶质瘤复发,26例为假性进展。胶质瘤复发组的rCBV值为2.81±1.26,假性进展组rCBV值为0.53±0.15,差异有统计学意义(P<0.01)。ROC曲线分析显示,以rCBV>2.15作为判断胶质瘤复发的临界值,其鉴别诊断复发与假性进展的敏感性和特异性分别为84.5%、100.0%。结论 MR-PWI可以较准确区分高级别脑胶质瘤复发还是假性进展,为疾病的诊治提供客观依据。

Objective To evaluate the role of magnetic resonance perfusion weighted imaging （MR-PWI） to distinguish the recurrence from pseudoprogression in high-grade brain glioma after comprehensive treatment. Methods A total of 56 patients were included. The patients with high-grade glioma after surgery, chemotherapy and radiation therapy were underwent 3.0T MR-PWI and contrast-enhanced Tl-weighted imaging （T1WI） during follow up. The value of relative cerebral blood volume （rCBV） of contrast-enhanced lesion in field of operation was calculated and stereotactic biopsy surgery was performed for the final pathologic examination. The receiver operating characteristic （ROC） was used to obtain the optimal cut-off value, sensitivity and specificity of rCBV in discrimination between recurrence and pseudoprogression. Results Thirty cases of recurrence and 26 cases of pseudoprogression were determined by histopathology. PWI analysis revealed lower rCBV values （0.53±0.15） in pseudoprogression than recurrence （2.81±1.26） （P〈0.01）. A rCBV threshold of 〉2.15 optimized differentiation of pseudoprogrcssion and glioma recurrence with a sensitivity of 84.5% and a specificity of 100.0%.Conclusion rCBV values obtained by PWI are useful objective diagnostic tools in the differentiation of glioma recurrence from pseudoprogression with a high degree of sensitivity and specificity.