表观弥散系数对脑淋巴瘤与胶质母细胞瘤的鉴别诊断

Differential diagnosis between cerebral lymphoma and gliomas multiblastoma by using of apparent diffusion coefficient

目的探讨脑淋巴瘤与胶质母细胞瘤(GMB)的弥散加权成像(DWI)影像学特征以及表观弥散系数(ADC值)对其的鉴别诊断价值。方法回顾性分析经病理证实的12例脑原发性淋巴瘤和15例GMB的常规MRI及DWI影像学表现,测量肿瘤实质的ADC值及rADC值,并进行组间对照分析。结果 12例淋巴瘤肿瘤实质在DWI上呈稍高或高信号,ADC值显著低于对侧正常表现白质[(0.593±0.176)×10-3mm2/s,(0.773±0.057)×10-3mm2/s,P=0.006];而15例GMB瘤体实性部分的DWI多为等或稍低信号,ADC值明显高于正常白质[(0.975±0.118)×10-3mm2/s,(0.768±0.077)×10-3mm2/s,P<0.001];淋巴瘤与GMB间的ADC值以及rADC值具有明显差异(P<0.001)。以ADC值为0.805×10-3mm2/s作为鉴别淋巴瘤与GMB的界值,其灵敏度100%,特异性92%,准确性96%;而rADC的界值为1.08,灵敏度100%,特异性95%,准确性100%。结论定量测量肿瘤实质ADC值有助于脑淋巴瘤及GMB的鉴别诊断,可以作为常规MR检查的补充手段。.

Objective：To investigate diffusion-weighted MR images（DWI） features of primary intracerebral lymphoma and gliomas multiblastoma（GMB）,and to further assess the differentiation between them by using apparent diffusion coefficient（ADC） value.Materials and Methods：Twelve patients with pathologically proved primary intra-cerebral lymphoma and 15 with GMB underwent MR examination,including DWI.The ADC values and ratio of ADC values（rADC） in solid parenchyma in all tumors were measured and compared between groups by two neuroradiologists.Results：Lymphoma showed slight-high or high intensity signal in DWI,and GMB were iso-or low intensity signal.Compared to normal appearing white matter,ADC values of lymphoma were significantly decreased [（0.593±0.176）×10-3 mm2/s,（0.773±0.057）×10-3 mm2/s,P=0.006],whereas those of GMB became obviously increased [（0.975±0.118）×10-3 mm2/s,（0.768±0.077）×10-3 mm2/s,P〈0.001].ADC values and rADC values were significantly different between lymphoma and GMB.Cutoff values to differentiate them were 0.805×10-3 mm2/s for ADC and 1.08 for rADC respectively.Conclusion：As a complementary method to conventional MR sequences,measurement of ADC value in DWI is helpful in the differentiated diagnosis on cerebral lymphoma and GMB.