MAGiC技术在高级别脑胶质瘤术后复发的诊断和鉴别诊断价值

Value of MAGiC in the diagnosis and differential diagnosis of postoperative recurrence in high-grade glioma

目的探讨增强前后一站式驰豫定量(MAGiC)技术在高级别脑胶质瘤(HCG)术后复发的诊断和鉴别诊断价值。方法选取36例HCG术后放疗患者的临床和MRI资料,其中经二次手术或MRI随访确诊复发者21例(复发组),确诊放射性脑损伤者15例(坏死组)。两组患者均行常规MRI、增强前后MAGiC扫描,选取复发强化区、周边水肿区和损伤强化区、周边水肿区为感兴趣区,分别得到对应各区增强前T_(1)值(T_(1)-pre)、T_(2)值(T_(2)-pre)和增强后T_(1)值(T_(1)+c)。以独立样本t检验或Mann-Whitney U检验比较各参数,并进行ROC曲线分析,以P<0.05为差异有统计学意义。结果HCG复发强化区和其周边水肿区的T_(1)+c缩短明显,低于放射性损伤区和其周边水肿区,差异有统计学意义(P<0.05)。复发强化区和损伤强化区T_(1)+c的ROC曲线下面积为0.957,诊断阈值622 ms,敏感度100%,特异度86.7%;两者周边水肿区T_(1)+c的ROC曲线下面积为0.898,诊断阈值为1333 ms,敏感度为100%,特异度为73.3%。结论MAGiC技术通过定量测量T_(1)+c值,可用于HCG术后复发和放射性脑损伤的鉴别,常规MRI联合增强前后MAGiC技术有助于提高HCG术后复发的诊断正确率。

Objective To evaluate the clinical application value of diagnosis and differential diagnosis of postoperative recurrence of high grade glioma(HCG)by unenhanced and Gd-enhanced magnetic resonance image compilation(MAGiC).Methods The clinical and MRI data of 36 patients with HCG after radiotherapy were prospectively enrolled,21 patients of them were diagnosed as recurrence by secondary operation or MRI follow-up,and 15 patients were diagnosed as radiation necrosis.Conventional MRI and MAGiC of before and after enhancement were performed in all patients.Regions of interest were manually delineated in unenhanced and enhanced relaxometry map in the area of enhancing focus and peripheral edema.T_(1)-pre,T_(2)-pre and T_(1)+c were obtained before and after enhancement respectively.The parameters between radioactive brain injury and recurrence groups were compared by Student-t test or Mann-Whitney U test after the normality and homogeneity test,P<0.05 indicated significant difference.Receiver operator characteristic(ROC)curve analysis was also done.Results T_(1)+c in the recurrence and peripheral edema areas of HCG was significantly shortened and lower than that in the radiation-injured and peripheral edema areas(P<0.05).The aera under the ROC curve of T_(1)+c of HGG recurrence and radiation injury was 0.957,with a diagnostic threshold of 622 ms,a sensitivity of 100%and a specificity of 86.7%.The aera under the ROC curve of T_(1)+c of peripheral edema areas was 0.898,with a diagnostic threshold of 1333 ms,a sensitivity of 100%and a specificity of 73.3%.Conclusion MAGiC technology can be used to differentiate postoperative recurrence of HCG from radiation brain injury by measuring T_(1)+c quantitatively.MRI combined with MAGiC of before and after enhancement can help to improve the diagnostic accuracy of recurrent HCG.