Probability of Cancerin Pulmonary Nodules Detected on First Screening CT首次CT发现肺部结节为肺癌的可能性Annette McWilliams Martin C. Tammemagi John R. MayoN Engl J Med 2013369:: EJMoa1214726背景美国国家肺部筛查试验显示应用低剂量胸部CT