64层螺旋CT重建层厚及重建间距与CAD肺结节检出准确性的关系分析  

Relationship of reconstruction slice thickness and interval with accuray of computer-aided detection system:detection of pulmonary nodules by 64-slice helical CT

作　　者：齐敏[1,2] 雷晓燕[2] 黄明刚[2] 张小玲[2] 吴晓红[2] 郭佑民[1] 

机构地区：[1]西安交通大学医学院第二附属医院影像中心,陕西西安710004 [2]陕西省人民医院影像中心,陕西西安710068

出　　处：《第四军医大学学报》2009年第10期932-935,共4页Journal of the Fourth Military Medical University

基　　金：陕西省科学技术研究发展计划(2007K12-02)

摘　　要：目的:评估不同重建层厚及重建间距对Lung Care软件CAD系统检出肺结节准确性的影响.方法:纳入48例肺结节患者,每位患者重建5组数据,层厚/间距分别为:0.75/0.70mm,1/1mm,3/3mm,5/1mm,5/5mm.利用ROC曲线对比不同重建参数时CAD的检测准确性.结果:根据参考标准共检出152个肺结节.在0.75,1mm层厚时的曲线下面积(Az)值(分别为0.86,0.84)均显著高于3,5mm层厚时(3/3,5/1,5/5mm时Az值分别为0.48,0.53,0.40)(P<0.05);重叠重建(5/1mm)时,CAD检出肺结节的Az值(Az=0.53)大于5mm层距时(Az=0.40),二者无显著性差异,但明显低于1mm层厚重建(Az=0.84,P<0.05).1mm层厚重建时CAD检出肺结节的灵敏度最高(84%);0.75mm层厚重建时平均每位患者的假阳性数最低(0.56).随层厚增加,CAD检出肺结节的平均直径逐渐增大,检出小结节的数目明显下降.结论:使用薄层重建(层厚0.75mm或1mm)图像时,CAD的检出准确性显著高于厚层重建(层厚3mm或5mm)时.重叠重建(5/1mm)可以提高CAD的准确性,但其作用非常有限.AIM ： To evaluate the effect of various reconstruction slice thicknesses and reconstruction intervals on diagnostic accuracy of pulmonary nodules with the computer-aided detection （CAD） system of LungCare software. METHODS： Forty-eight patients with pulmonary nodules, five sets of CT images were reconstructed in each patient by selecting five reconstruction slice thickness and interval combinations respectively： 0.75/0.70 ram, 1/1 mm,3/3 mm, 5/1 mm, 5/5 ram. The performance of the CAD system using different reconstruction combinations were compared with receiver operating characteristic curves analysis. RESULTS： 152 pulmonary nodules were detected according to the reference standard. The Az value was significant larger in 0.75 mm or 1 mm reconstruction section thickness （ Az = 0.86 and 0.84 for 0.75 mm and 1 mm, respectively） than that of 5.0 mm or 3.0 mm （ Az =0.48, 0.53 and 0.40 for 3/3 ram, 5/1 mm, 5/5 mm, respectively, P 〈 0.05 ）. In the case of the overlapping reconstruction （5/1 mm） , although the Az value of CAD （Az =0.53 ）was larger than that of 5 mm section interval（ Az = 0.40 ） , there is no significant difference, but significantly smaller than that of 1 mm slice thickness （ P 〈 0.05 ）. Sensitivity of CAD for 1 mm reconstruction section thickness（84% ）was the largest among the five sets ,while the number of false-positive findings per patient for 0. 75 mm thickness （0.56） was the smallest. With the increase of slice thick- ness, the average diameter of the nodule detected by CAD was increased, but the small nodule was decreased significantly. CONCLUSION：0.75 mm or 1 mm reconstruction section thick- ness outperforms that of 3.0 mm or 5.0 mm using CAD system in detection of pulmonary nodules. Overlap reconstruction enhances the accuracy of CAD but its role is very limited.

关 键 词：计算机辅助检测 肺结节 体层摄影术 螺旋计算机 图像重建 

分 类 号：R814.42[医药卫生—影像医学与核医学]