DSC-MRI鉴别诊断胶质母细胞瘤、单发脑转移瘤及脑淋巴瘤

目的 探讨动态磁敏感对比增强磁共振成像（DSC-MRI）鉴别诊断胶质母细胞瘤、单发脑转移瘤及脑淋巴瘤的价值。方法 回顾性分析经活检或术后病理证实的胶质母细胞瘤患者17例、单发脑转移瘤患者15例、淋巴瘤患者17例。患者术前均接受MRI常规平扫、增强及DSC-MRI扫描，获得脑血容量（CBV）伪彩图及时间-信号强度曲线，分别测量瘤体、瘤周水肿区及对侧正常白质区的CBV值，计算相对脑血容量（rCBV）值和瘤体的信号强度恢复百分比（PSR）。应用ROC曲线分析各指标对3种肿瘤的诊断效能。结果 胶质母细胞瘤、单发脑转移瘤及脑淋巴瘤均表现为肿瘤实性区域明显强化伴瘤周水肿。瘤体rCBV除胶质母细胞瘤与单发脑转移瘤无差异外，余两两比较差异均有统计学意义（P均<0.05）；瘤周rCBV除单发脑转移瘤与淋巴瘤无差异外，余两两比较差异均有统计学意义（P均<0.05）；瘤体PSR值除胶质母细胞瘤与单发脑转移瘤无差异外，余两两比较差异均有统计学意义（P均<0.05）。ROC曲线示瘤体PSR为鉴别淋巴瘤及非淋巴瘤的最佳指标，敏感度、特异度分别为100%和81.3%；瘤周rCBV为鉴别胶质母细胞瘤及单发脑转移瘤的最佳指标，敏感度、特异度分别为94.1%和86.7%。结论 rCBV和PSR结合可提高鉴别诊断3种脑肿瘤的效能。

Dynamic susceptibility contrast enhanced MRI in differential diagnosis of glioblastoma,solitary cerebral metastasis and cerebral lymphoma

Objective To investigate the value of the dynamic susceptibility contrast enhanced MRI (DSC-MRI) in differential diagnosis of glioblastoma,solitary cerebral metastatic tumors and cerebral lymphoma.Methods Seventeen patients with glioblastoma,15 cases with solitary cerebral metastatic tumor and 17 cases with cerebral lymphoma were analyzed retrospectively.All patients underwent conventional MR imaging,contrast-enhancement and DSC-MRI preoperatively.Pseudo color pictures of cerebral blood volume (CBV) and the time signal intensity curve were obtained from the raw data of DSC-MRI.The relative CBV (rCBV) were measured from regions of enhanced solid parts of the tumors,peritumoral region and contralateral normal white matter regions respectively.The percentage of signal intensity recovery (PSR) of enhanced solid parts of the tumors were measured.ROC curve analysis was performed to determine optimum indicator in differential diagnosis of three types of tumors,and the sensitivity and specificity were calculated.Results Three types of tumors all showed enhancement of solid area with obvious peritumoral edema.Besides the no difference between glioblastoma and metastasis in rCBV of solid parts of the tumors,there were statistically significant differences in comparisons of two types of tumors (all P<0.05).Besides the no difference between single brain metastases and lymphoma in rCBV of peritumoral regions,there were statistically significant differences in comparisons of two types of tumors (all P<0.05). The PSR of the solid parts of the tumors had no difference between glioblastoma and single brain metastases,while there were statistically significant differences in comparisons of two types of tumors (all P<0.05).ROC curve analysis showed sensitivity and specificity of the PSR values of solid parts of the tumors in differentiating lymphoma and non lymphoma were 100% and 81.3%.The rCBV of peritumoral regions was the optimum indicator for differentiating glioblastoma and solitary brain metastasis,the sensitivity and specificity were respectively 94.1% and 86.7%.Conclusion The combination of rCBV and PSR can improve the efficiency for diagnosing the three types of brain tumors.