DWI MRI在鉴别中枢神经系统淋巴瘤与高级别胶质瘤中的应用研究

目的探讨MRI及扩散加权成像(DWI)在中枢神经系统淋巴瘤(CNSL)与高级别脑胶质瘤中的鉴别诊断价值。方法分别对13例CNS淋巴瘤和20例高级别脑胶质瘤患者进行常规MRI检查及DWI检查,分析其影像学特征,计算感兴趣区的表观扩散系数(ADC值)及其与对侧正常脑白质ADC值之比值(rADC比值),进行统计学比较,根据受试者工作特征(ROC)曲线确定最佳诊断阈值(OT)。结果 CNS淋巴瘤组ADC值:(0.780±0.137)×10-3 m㎡/sec,rADCL比值:1.037±0.325;高级别胶质瘤组ADC值:(1.065±0.198)×10-3 m㎡/sec,rADCG比值:1.388±0.294,统计学差异明显(pADC值=0.031,prADC比值=0.001)。最佳诊断阈值分别为:(0.845×10-3 m㎡/sec(ADC值)、1.120(rADC比值),诊断敏感性85.0%(ADC值)、85.0%(rADC比值),特异性84.6%(ADC值)、86.9%(rADC比值)。结论CNS淋巴瘤与高级别胶质瘤除在信号强度、强化方式、坏死程度及瘤周水肿、占位效应等方面存在不同,DWI包括ADC值的测量能有效地鉴别CNSL与高级别胶质瘤。

The applying study of DWI-MRI in differential diganosis between central nervous system limphoma and high-grade glioma

Objective To explore the differential diganosis value of MRI and DWI between central nervous system limphoma and glioma. Methods Conventional MRI and DWI （Diffusion weighted image） scan were respectively performed on 13 cases of CNSL and 20 cases of high-grade glioma. Thair image characteristic were analyzed. The ADC（apparent diffu sion coefficient） Values of every lesion and that of contralateral normal white matter were measured and ADC ratio （rADC） was calculated. Optimum threshold was determined using ROC （receiver operating characteristic） curve analysis. Results ADC value of CNSL group was （0. 780±0. 137） × 10-3m n4/sec, rADCL ratio was 1. 037; ADC value of high- grade glioma group was （1. 065±0. 198） ×10-3mm2/sec, rADCG ratio was 1. 388±0. 294, which was obviously statistic differented（pADC value= 0. 031, prADC ratio= 0. 001）. Optimum threshold of ADC value, rADC ratio were 0. 845 ×10-3mm2/sec and 1. 120. Diagnosis sensitivity and specificity of ADC value were 85.0%, 84.6%, those of rADC ratio were 85.0%, 86.9%. Conclusion There are many distinctions on signal inteneity, enhancement pattern, necrosis degree, peritumoral edema and mass effect between CNSL and high grade glioma. Measurement of DWI and ADC value can effectively differenciate CNSL and glioma.