ADC值对颅内淋巴瘤与高级别胶质瘤鉴别诊断的价值研究

目的探讨ADC值在颅内淋巴瘤与高级别胶质瘤中的诊断价值。方法对15例颅内淋巴瘤和16例高级别胶质瘤(WHO胶质瘤分级:Ⅲ-Ⅳ级)行常规平扫、增强扫描和DWI成像,回顾性分析病灶的影像表现。感兴趣区(ROI)置于病灶在增强T1WI上明显强化且在ADC图上呈相对低信号部分,取病灶的最低ADC值,另外对同一病例以相同大小ROI置于对侧正常脑白质区测量三个ADC值,取其平均值。相对ADC值(rADC)取病灶最低ADC值与对侧正常白质区平均ADC值的比值。然后对淋巴瘤组和高级别胶质瘤组病例的ADC值和rADC值分别经行两样本t检验。结果淋巴瘤多发10例,单发5例,DWI图上15例病灶均见高信号,ADC图上均呈低信号,rADC1为100%。高级别胶质瘤单发15例,多发1例,DWI图上11例病灶见高信号,另5例未见明显高信号,ADC图上11例病灶见低信号,另5未见明显低信号,rADC1为69%。结论淋巴瘤与高级别胶质瘤的ADC值和rADC值差异无统计学意义,DWI结合常规MRI形态学表现有助于颅内淋巴瘤与高级别胶质瘤的鉴别诊断。

The value of ADC value to differentiation between intracranial Lymphomas and High-grade Gliomas

Objective To determine if apparent diffusion coefficient （ADC） and conventional MRI can be used to differentiate intracranial lymphomas and high-grade gliomas. Methods 15 cases with lymphomas and 16 cases with high-grade gliomas （WHO grade Ⅲ- Ⅳ） underwent conventional MRI, enhanced MRI and diffusion weighted imaging （DWI） that were retrospectively reviewed. Regions of interest （ROI） were drawn on low signal regions of apparent diffusion coefficient （ADC） maps in enhancing tumor. The lowest ADC values were recorded. Three same Regions of interest were drawn on the contralateral normal-appearing white matter. The average ADC values were obtained. Relative apparent diffusion coefficient （rADC） was a ratio that the lowest ADC value divided the average ADC value in the same patient. The ADC values and rADC values in intracranial lymphomas were compared with those in high-grade gliomas as by using a two tailed t test. Results The lesions were solitary in 5 and multiple in 10 with lymphomas. All lesions showed high signal on DWI map and low signal on ADC map with lymphomas. The rADC less than 1 reached 100%. The lesions were solitary 15 and multiple in 1 with high-grade gliomas. 11 cases showed high signal on DWI map and low signal on ADC map and 5 cases did not show high signal on DWI map and low signal onADC map with high-grade gliomas. The rADC less than 1 reached 69%. Conclusion ADC values and rADC values were not marked different on lymphomas and high-grade gliomas. But combined with conventional MRI, DWI may be helpful to differentiate intracranial lymphomas and high-grade gliomas.