磁共振扩散加权成像对脑肿瘤未强化病灶的显示价值

目的评价磁共振扩散加权成像对脑肿瘤未强化部分的诊断价值。方法对不同级别的76例脑胶质瘤普通MRI及扩散图像信号特征进行分析,测量并比较增强及未增强病灶、水肿区的相对表观扩散系数（rADC）值。并进行扩散图像对瘤灶的诊断试验评价。结果胶质瘤增强与未增强区域的rADC值没有差异,而未增强区域rADC与周围水肿区rADC值的差异有高度统计学意义（P〈0.01）。未强化部位在扩散成像中有很好的显示。DWI和ADC图上诊断的敏感度为76.8%,特异度为90.2%。结论对于未明显强化胶质瘤或胶质瘤的未强化区域,ADC与DWI相结合,能够在一定程度上弥补肿瘤未强化的缺点,对未强化胶质瘤的诊断具有重要价值,为手术区域的研判及临床预后提供参考依据。

Evaluation of MRI Diffusion-weighted Imaging in Diagnosis of Unenhanced Brain Glioma

Objective To determine whether diffusion-weighted imaging could be used to distin- guish brain glioma which is not be enhanced. Methods Seventy-six cases with glioblastomas were an- alyzed. The appearance of the lesions（nonenhancing and enhancing tumor） and conventional MRI, diffu- sion-weighted imaging, rADC values, sensitivity and specificity were studied. Results The rADC values of enhancing and nonnhancing gliomas were in the same range other than oedema by statistical analysis （P〈0.01）. The ADC and DWI map of nonhancing tumor were showed distinctly in the most. The sensi- tivity and specificity in diagnosing brain tumor were 76.8% and 90.2% respectively by DWI associated with ADC. Conclusion Diffusion-weighted ing tumor components and provide valuable Imaging may be a useful tool in characterizing nonenhanc- information for operation and radiotherapy.