Results The sensitivity of low dose spiral CT and MPR was 100% in diagnosing the foreign body in trachea, and 95.65% in the third branches of bronchi.

• 结果低剂量螺旋CT及MPR图像对气管异物诊断准确性为100%25；对3级以下支气管异物诊断准确性为95.；65%25。