Incidental findings on imaging: seeing the wood from the trees

The coronary artery calcium (CAC) score is widely believed to be an important tool in determining the risk of developing heart disease. The measurement of this score has traditionally been based on using electrocardiography triggered computed tomography (CT). This confers an advantage over non-gated CT scanning by acquiring images during diastole, which reduces motion artefact and avoids missing areas of coronary artery calcification. Radiologists are, therefore, cautious when reporting CAC on non-gated CT scans due to concerns that it may not be accurate. This means that there is currently no obligation, from a radiology perspective, to report on the degree of CAC on non-gated CT scans. While this has been acceptable for a long time, emerging evidence may force us to change our practise.