Progressive Radiation Dose Reduction From Coronary Computed Tomography Angiography in a Statewide Collaborative Quality Improvement Program

Abstract

Background— A best-practice intervention previously demonstrated significant dose reduction over a period of one year. We sought to evaluate whether this reduction would be incremental and sustained by promoting new scanner technology in the context of an ongoing quality improvement program during a 3-year period in a statewide registry of coronary computed tomography angiography. Methods and Results— In this prospective, controlled, nonrandomized study involving 11 901 patients at 15 Michigan centers participating in the Advanced Cardiovascular Imaging Consortium, radiation doses and image quality were compared between the following periods: control (May to June 2008) versus follow-up I (July 2008 to June 2009) and follow-up I versus follow-up II (July 2009 to April 2011). Intervention during these study periods included continuous education, feedback, and mandatory participation in this initiative. The median radiation dose remained unchanged from control to follow-up I: dose-length product of 697 (interquartile range, 407–1163) to 675 (interquartile range, 418–1146) mGy·cm ( P =0.93). With the introduction of newer technology in follow-up I period, there was incremental 31% decrease during follow-up II to median dose-length product of 468 (interquartile range, 292–811) mGy·cm ( P <0.0001). No significant change was noted in the percentage of diagnostic quality scans from follow-up I (92%) to follow-up II (92.7%). Conclusions— Although ongoing application of a best-practice algorithm was associated with sustaining previously achieved targets, the use of newer scanner technology resulted in incremental radiation dose reduction in a statewide coronary computed tomography angiography registry without image quality degradation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00640068.