数字体层图像后处理方法对检测肺结节准确性的影响

摘要

目的 探讨数字体层图像两种后处理方法(位移叠加法与滤波反投影法)对肺结节检测准确性的影响.方法 采集经CT证实的50例肺部结节患者的数字体层图像,采用滤波反投影法和位移叠加法进行后处理.由3名不同年资的放射诊断医师阅片并记录评分结果.102个CT证实的结节按直径分为3组:＜5 mm、5～10 mm、>10 mm组;按密度分为实性密度组及毛玻璃密度组.对两种处理方法检出的肺结节进行统计分析.结果 位移叠加法检出肺结节52个,滤波反投影法检出86个,差异有统计学意义(P＜0.001).对于直径＜5 mm和5～10 mm组,滤波反投影法检出的肺结节数均多于位移叠加法(P=0.001、0.005).结节直径>10 mm时两种方法的检出数量差异无统计学意义(P=0.317).在不同密度组中,滤波反投影法检出的结节亦较多,与位移叠加法差异有统计学意义(P均<0.05).结论 滤波反投影法对检出直径≤10 mm的肺结节、实性结节和毛玻璃结节均优于位移叠加法.%Objective To evaluate the effect of shift -and-add (SAA ) and filtered back projection (FBP) in digital tomosynthesis on pulmonary nodules detection accuracy . Methods Fifty patients with small nodules confirmed by chest CT were selected . Digital tomosynthesis images were obtained and processed with SAA and FBP . Three radiologists of different experiences independently reviewed and recorded the results of pulmonary nodules . Totally 102 nodules confirmed with CT were devided into 3 groups : Group of nodules ＜ 5 mm 5-10 mm and ＞10 mm , respectively , and 2 groups according to the density : Group of' solid density nodules and ground-glass density . The results of SAA and FBP were analyzed statistically . Results SAA detected 52 pulmonary nodules , while FBP f'ound 86 ( P＜ 0. 001) . For nodules with diameter ＜ 5 mm and 5-10 mm , FBP displayed more nodules than SAA ( P= 0. 001 . 0. 005 ) , while no difference was found hetween two methods for ＞10 mm group ( P= 0. 317) . For solid density and ground-glass density nodules . FBP showed more nodules than SAA (both P＜ 0. 05 ). Conclusion FBP is superior to SAA in detection of nodules with diameter ≤10 mm,small pulmonary nodules with solid density and ground-glass density .