The ACR Lung Cancer Screening Registry (LCSR) is designed to systematically audit the quality of interpretation of screening lung CT exams. The registry is based on the ACR Lung Imaging Reporting and Data System (Lung-RADS), which is the product of the ACR Lung Cancer Screening Committee subgroup on Lung-RADS. This Lung-RADS system is a quality assurance tool designed to standardize lung cancer screening CT reporting and management recommendations, reduce confusion in lung cancer screening CT interpretations and facilitate outcome monitoring. The ACR LCSR will capture Lung-RADS recommendations and monitor and compare appropriate use of Lung-RADS.