Drs. John Carroll and John Messenger are innovators in the field of rotational coronary angiography. Dr. Carroll, together with S. James Chen, PhD, is a co-inventor of patented 3D vascular reconstruction and analysis software. Drs. Carroll and Messenger are part of the interventional cardiology group at the University of Colorado in Denver, where they work with state-of-the-art equipment to optimize clinical protocols using rotational angiography (RA) and three-dimensional rotational angiography (3DRA) to image the coronary tree. The group has used RA in coronary interventions since 2000, and they now perform approximately 800 RA procedures per year.