脑胶质瘤MR弥散加权成像与病理对照研究

Correlation between diffusion-weighted Imaging and histopathologic state of gliomas

目的:通过MR DWI技术分析评估脑胶质瘤ADC值与微观病理状态的关系,探讨ADC值在脑胶质瘤中的临床应用价值。方法:采用美国GE公司1.5T HDMR机,对30例胶质瘤进行了常规MRI及弥散加权成像,测量肿瘤实质部分的ADC值,分析不同级别胶质瘤的ADC值的差异性,并比较ADC值与细胞构成和核质比的相关性。结果:低级别胶质瘤(11.74±1.32)与高级别胶质瘤肿瘤实质ADC值(9.55±1.21)相比差异有统计学意义(P<0.05),低级别胶质瘤较高级别胶质瘤ADC值高。胶质瘤的ADC值与细胞构成(r=-0.80,P<0.01)和核质比(r=-0.73,P<0.01)成负相关,与细胞构成的相关性较核质比高;胶质瘤的ADC值与肿瘤级别也呈明显负相关(r=-0.73,P<0.001)。结论:弥散加权图像中胶质瘤的ADC值可预测肿瘤的级别,并有助于在活体上对胶质瘤的病理微观状态进行判断,为MRI从微观角度观察胶质瘤的结构变化提供了基础,并为临床诊断和治疗提供了新的评价指标。

Objective： To clarify the correlation between apparent diffusion coefficient （ADC） and microscopic histopathologic state of gliomas through MR DWI technology, to evaluate the value of clinical application of ADC value of brain gliomas. Methods： All examinations were performed on Signa 1.5T Excite HDMR. All patients underwent MRimaging, which included conventional MR imaging , DWI and contrast - enhancement T1 - weighted imaging. ADC values of the solid components of the tumors were estimated and compared between different groups, and the correlation of ADC values with the cellularity and nuclear- to -cytoplasm （N/C） ratio was analyzed. Results： The ADCs of low - grade glioma were significantly higher than those of high -grade glioma（ P 〈 0. 05 ）. A negative correlation existed between the ADC value and both the cellularity （r = -0.80, P 〈 0.01 ） and the N/C ratio（ r = - 0.73 ,P 〈 0. 01 ）. Conclusion： The apparent diffusion coefficient may be predictive of tumor classification and may be a useful tool in characterizing tumor cellularity and nuclear - to - cytoplasm （ N/C ） ratio. These parameters are not available in standard MR imaging. Therefore, diffusion - weighted imaging may enhance the diagnostic and treated process in tumor.