双能减影与常规DR检测肺结节模型的实验研究

Experimental Study of Dual Energy Subtraction and Conventional Digital Radiography in Detecting Simulated Pulmonary Nodules

目的比较双能减影(DES)与常规数字X线成像(CDR)对肺结节模型(SPNs)的检测能力。材料与方法将200个直径为4 mm塑料小球作为SPNs置于健康志愿者右胸上部,在屏气状态下拍摄DES和CDR。由3位放射科医师各自独立阅片,计算CDR与DES的敏感性、特异性、阳性试验预测值、阴性试验预测值、准确率,并进行Pearson Chi-square检验。结果DES检测SPNs的敏感性、阴性试验预测值、准确率分别为69.3%、73.9%和77.9%,CDR分别为52.8%、63.9%和70.0%,DES均优于CDR(P<0.05)。DES检测SPNs的特异性和阳性试验预测值分别为86.4%和83.6%,CDR分别为83.1%和75.6%,DES与CDR接近(P>0.05)。结论DES可以去除肋骨对SPNs的遮挡,使DES对SPNs的检测能力优于CDR,提示DES对小肺结节的筛查具有良好的应用价值。

Objective To compare the performance of dual energy subtraction （DES）with that of conventional digital radiography（CDR） in detecting simulated pulmonary nodules（ SPNs）. Materials and Methods 200 plastic balls which were 4 mm in diameter were taken as SPNs, and were placed on the right upper thorax of a healthy volunteer. The SPNs were examined by DES and CDR. Images were estimated by 3 radiologists separately. The sensitivity, specificity, predictive value of positive test, predictive value of negative test, accuracy were calculated and were analyzed by Pearson Chi square analysis. Results The sensitivity, predictive value of negative test, accuracy of SPNs detecting were 69.3% ,73.9% ,77.9% respectively in DES, those were 52.8%, 63.9%, 70.0% respectively in CDR, DES was superior to CDR with significant difference （ P 〈 0.05）. The specificity, predictive value of positive test of SPNs detecting were 86.4% , 83.6% respectively in DES, those were 83.1%, 75.6% respectively in CDR. DES was close to CDR （ P 〉 0.05 ）. Conclusion DES is superior to CDR in SPNs detecting without superposition of ribs. There is a good outlook for the application of DES in small pulmonary nodules screening.