ADC值对脑星形细胞瘤分级及鉴别诊断的研究

目的：探讨表观扩散系数（Apparent diffusion coefficient,ADC）测量值在脑星形细胞瘤分级及鉴别诊断中的价值和意义。方法：病变组41例,均经手术病理或临床随访确诊,术前均行常规MRI平扫、增强检查、扩散加权成像（DWI）,然后分别测量肿瘤实体、囊变区及近侧瘤周区等不同部位的ADC值。结果：肿瘤实体ADC值随着肿瘤恶性度升高而降低。低级别胶质瘤（Low-grade astrocytoma,LGA）与高级别胶质瘤（High-grade astrocytoma,HGA）比较,两者瘤周及囊变的ADC值有统计学差异（P〈0.008 3）。HGA与转移瘤之间仅瘤周的ADC值有统计学差异。脑膜瘤实体的ADC值最低,与HGA、LGA实体之间有统计学差异。结论：ADC值对星形细胞瘤分级及鉴别诊断有一定帮助,与MR增强检查相结合可提高脑肿瘤的诊断效率。

Value of Apparent Diffusion Coefficient on Cerebral Astrocytomas Grading and Differentiation

Objective：To evaluate the apparent diffusion coefficient （ADC） in cerebral astrocytomas grading and differentiation. Methods：Forty-one patients with histologically or clinically pro~zed brain diseases were prospectively e- valuated with conventional and contrast material-enhanced MR imaging and DWI before surgery. 1ADC maps were cal culated and regions of interest （ROI） were manually placed over areas of!solid component, peritumoral region and cystic region of tumors, and various areas of the control group. Results ：According to our results, the higher the tumor WHO grade, the lower the ADCs in astrocytic tumors. There were significant differences in the ADCs in peritumoral and cystic regions between LGA and HGA. The peritumoral ADCs in metastases was significantly higher than that in HGA. The tumoral ADCs in meningiomas was the lowest, and was significantly lower than that in HGA and LGA. Conclusion： ADC values are useful in cerebral astrocytomas grading and differentiation, and with enhanced MRI will improve the diagnostic effectiveness of brain tumor.