DWI及ADC值在脊柱转移瘤诊断中的应用

Diffusion-weighted imaging(DWI) and apparent diffusion coefficient(ADC value) diagnosis of metastases in the spine

目的 :探讨DWI及ADC值在脊柱转移瘤诊断中价值。方法 :收集我院临床确诊的脊柱转移瘤30例脊柱转移组,脊柱良性病变25例(良性病变组)。55例均行常规矢状位、横轴位及DWI扫描,b值取0、800 s/mm2,分别测量得2组病变ADC值。主观评价并比较2组的DWI病灶信号强度。采用ROC曲线,获得最佳DWI及ADC值界值,以及诊断敏感度、特异度,两者联合指标的敏感度、特异度。结果:椎体病变T1WI呈低信号或以低信号为主的混杂信号,T2WI脂肪抑制后为高信号、混杂高信号。良性病变组DWI以稍高信号为主(17/25),脊柱转移瘤组DWI以高信号为主(24/30),2组差异有统计学意义(Z=4.477,P<0.001)。测得平均ADC值:脊柱转移瘤组为(0.843±0.189)×10-3mm2/s;良性病变组为(1.204±0.184)×10-3mm2/s,2组差异有统计学意义(t=7.131,P<0.001)。当病变DWI为稍高信号,鉴别脊柱良恶性病变ROC曲线下面积为0.812,敏感度80%,特异度80%;2组ADC值鉴别脊柱良恶性病变ROC曲线下面积为0.920,最佳临界值为0.947×10-3mm2/s,敏感度76.67%,特异度96%。DWI病变信号为稍高及高信号,ADC值≤0.947 4×10-3mm2/s,满足其中之一诊断为恶性病变的诊断敏感度90%,特异度80%。结论:常规MRI结合DWI及ADC值对诊断脊柱转移瘤具有重要价值。

Objective：Discussion on diffusion-weighted imaging（DWI） and apparent diffusion coefficient（ADC value） value in the diagnosis of metastatic spine. Method：Divided into two groups of cases,30 cases of metastatic spinal tumor group,25 cases of benign lesions of the spine,All patients underwent routine sagittal,axial and DWI scanning,taking b of 0 and 0.800 s/mm2 to obtain two sets of lesion ADC value. Subjective evaluation of spinal metastases group,benign acute vertebral compression fracture group DWI lesion signal intensity in both groups,Into other signals,slightly higher signal,high signal 3 group,Line statistical analysis,Is there a significant difference between the two groups,using ROC curves,get the best DWI and ADC value cutoff and diagnostic sensitivity and specificity,sensitivity,specificity,combination of the two indexes. Result：All vertebral lesions T1 WI low signal or low signal-based,after fat suppression T2 WI high signal,mixed high signal. DWI benign lesions to slightly higher signal-based（17/25）,spinal metastases DWI high signal-based group（24/30）. The mean ADC value measured：spinal metastases group（0.843±0.189）×10-3mm2/s;benign group（1.204±0.184）×10-3mm2/s. ADC values of benign lesions metastasis ADC value is high compared with the spine,T-test（t=7.131,P 〈0.001）,spinal metastases group and spinal benign lesions was statistically significant difference between ADC values. Subjective evaluation of two DWI signal intensity lesions,benign lesions mainly DWI signal intensity and so on,higher signal-based,spinal metastases DWI signal lesions were mainly higher,significantly higher signal-based,Rank test（Z=4.477,P 〈0.001）,two sets of DWI signal intensity difference was statistically significant;When DWI lesion is slightly hyperintense area under the curve of the spine discriminating benign and malignant lesions ROC 0.812,sensitivity =80% specificity=80%;Under two differential ADC value of benign and malignant lesions of the spine ROC curve area of 0.920,the best critical value of 0.947×10-3mm2/s,sensitivity=76.67%,specificity=96.0%. When DWI lesion signal is slightly high signal,ADC≤0.9474×10-3mm2/s,as long as there is an index satisfying the condition can be diagnosed as malignant lesions,the sensitivity of the two joint indices specificity =90% =80%. Conclusion：Conventional MRI combined with DWI and ADC values has great value in the evaluation of spinal metastases.