PURPOSE: The aim of this study was to identify organizational factors and quality improvement strategies associated with lower radiation doses from abdominal CT. METHODS: Cross-sectional survey was administered to radiology leaders, along with simultaneous measurement of CT radiation dose among 19 health care organizations with 100 imaging centers throughout the United States, Europe, and Japan, using a common dose management software system. After adjusting for patient age, gender, and size, quality improvement strategies were tested for association with mean abdominal CT radiation dose and the odds of a high-dose examination. RESULTS: Completed surveys were received from 90 imaging centers (90%), and 182,415 abdominal CT scans were collected during the study period. Radiation doses varied considerably across organizations and centers. Univariate analyses identified eight strategies and systems that were significantly associated with lower average doses or lower frequency of high doses for abdominal CT examinations: tracking patient safety measures, assessing the impact of CT changes, identifying areas for improvement, setting specific goals, organizing improvement teams, tailoring decisions to sites, testing process changes before full implementation, and standardizing workflow. These processes were associated with an 18% to 37% reduction in high-dose examinations (P < .001-.03). In multivariate analysis, having a tracking system for patient safety measures, supportive radiology leaders, and obtaining clear images were associated with a 47% reduction in high-dose examinations. CONCLUSIONS: This documentation of the relation between quality improvement strategies and radiation exposure from CT examinations has identified important information for others interested in reducing the radiation exposure of their patients.