In the search of coronary calcium

The recognition of coronary artery calcium (CAC) as an indicator of coronary artery disease for more than 30 years has created a great interest in methods for its accurate assessment. In this review we present the imaging techniques capable of detecting CAC and discuss their current status in clinical practice. The first non-invasive CAC imaging method was chest radiography, although early recognized as insensitive. Fluoroscopy and digital fluoroscopy improved CAC detection compared to plain chest radiography; however, their potential in reliable CAC quantification and detection of small CAC amounts is limited. The evolution of computed tomography (CT) offered new perspectives in the field of CAC assessment. Electron beam and-mainly nowadays-multidetector CT constitute the established CAC scoring techniques. Recent evidence shows that CAC evaluation is feasible even on standard chest CT and CT coronary angiography. Cardiac echocardiography, positron emission tomography and magnetic resonance imaging currently have limited capability of CAC assessment. Invasive examinations like coronary angiography may reveal CAC, a finding with potential implications in coronary interventions. Intravascular ultrasound and optical coherence tomography have great potential in assessing the extent and pattern of CAC, however, quantification is challenging and they are not suitable for screening. Angioscopy, a demanding and evolving technique, can possibly detect surface CAC. Further evolution and refinement of CAC detection methods is expected to lead to their more widespread application and even greater usefulness into clinical practice.