脊椎病变的MR弥散加权成像研究

目的 结合常规MER,探讨磁共振弥散加权成像对脊椎良恶性病变的鉴别诊断价值.方法 选择64例脊椎良恶性病变患者为研究对象.应用1.5T磁共振扫描仪采集数据.包括常规T1WI、T2WI和DWI,DWI b值分别选择70 s/mm2、100 s/mm2、165 s/mm2、300 s/mm2、500 s/mm2,经Functool 2软件分析处理得到病变部位的表观弥散系数(ADC)值和指数弥散系数(EDC)值.采用统计软件包(SPSS 13.0)对以上观察内容进行统计学分析.结果 DWI中,脊椎良、恶性病变的信号差异无显著性.b≤100 s/mm2时,弥散效应不明显;b>300 s/mm2时,图像信-噪比过低.当b=165 s/mm2时,其图像可满足诊断需要.当b=165 s/mm2时,脊椎良性病变的ADC值为(3.19±O.33)×10-4mm2/s,EDC 值为(715.68士28.36)×10-3;脊椎恶性肿瘤(转移瘤)的AIN;值为(1.87±0.12)×10-4mm2/s,EDC值为(1466.25±41.69)×10-3.与恶性肿瘤相比,脊椎良性病变的ADC值明显偏高,EDC值明显偏低.结论 脊椎良、恶性病变的DWI信号差异无显著性.因此,不能单纯根据DWI信号的高低对脊椎良、恶性病变进行鉴别诊断.脊椎EPI-DWI中,当b值在100～300 s/mm2时,能够得到适合临床诊断需要的图像.当b=165 s/mm2时,脊椎ADC值和EDC值可作为良恶性病变鉴别诊断的指标之一.若AIX;值大、EDC值小,则提示病变良性可能较大;反之则提示恶性肿瘤可能.

Diffusion-weighted imaging of vertebral diseases

Objective To evaluate the clinical application value of diffusion weighted imaging in differentiation of benign and malignant vertebral diseases. Methods Conventional MRI and DWI with b values as 70 s/mm²,100 s/mm²,165 s/mm²,300 s/mm² and 500 s/mm² respectively were performed in 64 patients with vertebral disease. ADC and EDC values were obtained on delineated ROI by the Functool 2 software system. The data were analyzed with soft-ware (SPSS, version 13.0). Results There was no significant difference of signal of DWI between benign and malignant vertebral diseases. The diffusion effects was not significant when b value was smaller than 100 s/mm². The signal noise ratio was so low when b value was larger than 300 s/mm². With b value as 165 s/mm², the diffusion images were suitable for clinical diagnosis. When b value was 165 s/mm², the ADCs of benign vertebral diseases were higher than those of malignant ones ( ×10^-4 mm² /s), and EDCs of benign group were lower than those of malignant ones ( ×10^-3). Conclusion The signal of DWI is not reliable to distinguish benign from malignant vertebral diseases, however, ADCs and EDCs of diffusion weighted imaging are helpful for differentiation.