磁共振全身扩散加权成像在肺癌骨转移中的应用价值

目的比较全身MR扩散加权成像(WB-DWI)、常规磁共振成像(MRI)/CT扫描及二者联合应用(WB-DWI+MRI/CT)对非小细胞肺癌(NSCLC)骨转移的检出能力。方法对60例病理学确诊的NSCLC患者行WB-DWI、胸部CT扫描,并对可疑骨转移部位行常规MRI扫描,应用ROC曲线评价WB-DWI、常规MRI/CT及WB-DWI+MRI/CT在NSCLC骨转移中的诊断价值,应用方差分析比较弥散系数(ADC)值在良恶性病变鉴别诊断中的价值。结果①WB-DWI、MRI/CT、WB-DWI+MRI/CT诊断NSCLC骨转移的曲线下面积(Az)分别是0.935,0.961,0.977,二者联合应用特异度及正确诊断指数最高,有助于提高NSCLC转移病灶的检出。②NSCLC骨转移瘤平均ADC值高于良性骨病变(0.89±0.12)×10-3与(1.51±0.15)×10-3mm2/s],取临界值1.12×10-3mm2/s,其诊断NSCLC骨转移的灵敏度、特异度及正确诊断指数均达100%。结论 WB-DWI是常规MRI/CT的有益补充,二者联合应用在NSCLC骨转移诊断与鉴别诊断中具有一定价值。

The utility of whole-body diffusion-weighted imaging for the diagnosis and identify of bone metastases in non-small cell lung cancer

Objective To prospectively and directly compare the capability of whole-body diffusion-weighted imaging （DWI）, standard magnetic resonance imaging （MRI）/eomputed tomography （CT） and whole-body diffusion- weighted imaging DWI with standard MRI/CT for assessment of bone metastases in non-small cell lung cancer （NSCLC） patients. Methods A total of 60 NSCLC patients prospectively underwent whole-body DWI, standard MRI in suspicious bone metastases parts and a chest CT within one week after inspection. Final diagnosis of the bone metastases in each patient was determined on the basis of results of all radiologic and follow-up examinations. Final diagnosis based on each of the methods was made by consensus of two readers. Receiver operating characteristic （ROC） analysis was used to compare the capability for bone metastases assessment among whole-body DWI, standard MRI/CT and whole-body DWI with standard MRI/CT. The detection ability of bone metastases with different size were compared with test. The differential diagnosis value of apparent diffusion coefficient （ADC） in benign and malig- nant bone lesions was compared with the variance analysis. Results @Area under ROC curve （Az） value of whole- body DWI with standard MRI/CT （Az=0.977） were larger than that of whole-body DWI（Az=0.935） and standard MRI/ CT （Az=0.961）, and the specificity and accuracy were also the highest. It was confirmed that whole-body DWI with standard MRI/CT could help to improve the detection ability of bone lesions in NSCLC cases. @The ADC value of benign and malignant bone lesions were determined. The ADC value of malignant bone metastases were significantly lower than those of benign lesions （0.89±0.12）×10^-3vs （1.51±0.15）×10^-3mm2/s]. The sensitivity, specificity, accuracy were 100% with the cut-off value of 1.12×10^-3 mm2/s. Conclusion Whole-body DWI was the beneficial supplements of standard MRI/CT. Combined with ADC value, it could be used for assessment and differential diagnosis of bone metastases in NSCLC patients.