探讨磁共振扩散加权成像在鉴别良恶性椎体骨折中的诊断价值

Diagnostic Value of Diffusion Weighted Magnetic Resonance Imaging in Differentiation of Benign and Malignant Vertebral Fractures

目的探讨磁共振扩散加权成像(DWI)在良恶性椎体骨折中的鉴别诊断价值。方法根据临床随访和病理资料将29例椎体骨折患者分为两组,良性组(15例)为急性良性骨折,恶性组(14例)为病理性骨折,对所有患者进行脊柱DWI检查,分别记录病灶和正常椎体的表观扩散系数(ADC)值,包括最大值、最小值和平均值,计算其差值(da、di、de),分析比较两组的ADC值、差值,并绘制受试者工作特征(ROC)曲线。结果恶性组较良性组的ADC最大值(1.55×10^(-3)mm^2/s vs.1.99×10^(-3)mm^2/s,P<0.01)、ADC最小值(0.55×10^(-3)mm^2/s vs.0.79×10^(-3)mm^2/s,P<0.05)、ADC平均值(1.08×10^(-3)mm^2/s vs.1.47×10^(-3)mm^2/s,P<0.01)及最大值差值da(1.08×10^(-3)mm^2/s vs.1.58×10^(-3)mm^2/s,P<0.01)、最小值差值di(0.52×10^(-3)mm^2/s vs.0.78×10^(-3)mm^2/s,P<0.01)、平均值差值de(0.93×10^(-3)mm^2/s vs.1.32×10^(-3)mm^2/s,P<0.01)要低。绘制ROC曲线后,病灶ADC最大值、最小值、平均值及其与正常椎体ADC的差值da、di、de的曲线下面积(AUC)分别为0.809,0.791,0.864,0.821,0.824,0.880。结论定量分析ADC值有助于鉴别椎体良恶性骨折,差值de的鉴别诊断准确性最高,病灶ADC平均值其次。

Objective To investigate the value of diffusion weighted magnetic resonance imaging with apparent diffusion coefficient（ ADC） mapping for differentiating benign from malignant vertebral fractures. Methods Conventional MRI and DWI imaged thirty-nine vertebral lesions in 29 patients. ADC values（ maximum,minimum,mean） of vertebral lesions and adjacent normal vertebrae were recorded. The difference in values of ADC（ da,di,de） between the abnormal and normal vertebrae were computed for each patient. ADC and d values in the benign and malignant vertebral fractures were assessed（ independent-samples t test,receiver operating characteristic analysis）. Results There were 19 benign and 20 malignant（ 19 vertebral metastases,1 vertebral aggressive hemangioma） vertebral fractures in 29 patients. There were lower maximum（ 1. 55 × 10^-3mm^2/s vs. 1. 99 × 10^-3mm^2/s,P〈0. 01）,minimum（ 0. 55 × 10^-3mm^2/s vs. 0. 79 × 10^-3mm^2/s,P〈0. 05）,mean（ 1. 08 × 10^-3mm^2/s vs. 1. 47 × 10^-3mm^2/s,P〈0. 01） ADC values and da（ 1. 08 × 10^-3mm^2/s vs.1. 58 × 10^-3mm^2/s,P〈0. 01）,di（ 0. 52 × 10^-3mm^2/s vs. 0. 78 × 10^-3mm^2/s,P〈0. 01）,de（ 0. 93 × 10^-3mm^2/s vs.1. 32 × 10^-3mm^2/s,P〈0. 01） values in malignant lesions compared with those in the benign fractures. Areas under ROC curve for maximum,minimum,mean ADC values of lesions and da,di,de values were 0. 809,0. 791,0. 864,and0. 821,0. 824,0. 880. Conclusion Diffusion-weighted magnetic resonance imaging is a useful tool to supplement information provided by conventional sequences. ADC values and the difference in the values of ADC between abnormal and normal vertebrae are valuable to distinguish malignant fractures from benign fractures. The value of de offered the highest accuracy for characterization（ sensitivity 86. 7%,specificity 86. 5%）,followed by mean ADC value of lesions.