We searched 11 electronic information sources for trials from their inception until November 1, 2010: Cardiosource Clinical Trials, the Cochrane Central Register of Controlled Trials, the Cochrane Health Technology Assessment Database, Excerpta Medica (EMBASE), Healthstar, the International Standard Randomized Controlled Trial Number Register, MEDLINE, National Institutes of Health ClinicalTrials.gov, UpToDate Online, Web of Science with Conference Proceedings, and What's What Online. The search was developed and performed in concert with a health informatics specialist. We used search terms related to imaging technologies and cardiovascular disease or risk factors. For example, to identify articles on computed tomography, we used variants and combinations of the following terms: Agatston, computerized axial tomography, computed tomography, computed tomographic angiography, computerized tomography, CAC, CACS, CCTA, CT, CTA, CTCA, calcification score, calcium score, cardiac gating, cardiac gated, coronary artery calcification, coronary artery calcium, coronary calcification, coronary calcium, detector row, double helical, dual energy, dual source, electron beam, EBCT, EBT, MDCT, MSCT, multidetector, multislice, sixteen slice, and sixty-four slice. We supplemented the electronic search by scrutinizing the reference lists of primary articles, review articles, editorials, and imaging guidelines, as well as consulting experts in the field and screening personal files. Finally, we performed a gray literature search of the Internet, thesis dissertations, and abstract listings to locate additional trials. Pairs of reviewers performed the search and adjudicated study inclusion based on a standardized eligibility rating form (D.G.H. with K.G.S., J.D.S., D.A.A., and G.K.D.). Disagreements between reviewers were resolved through consensus.