This study shows that coronary artery calcification (CAC) is a frequent incidental finding in middle-aged adults undergoing chest CT, and over a quarter of patients with CAC showed moderate/severe disease. In only 35% of the cases was the presence of CAC mentioned by the reporting radiologist, which is slightly lower than in other studies^[4]. However, a relatively low number of unreported CAC was categorised as moderate or severe disease. The traditional management of moderate and severe coronary artery calcification based on the Agatston categories includes aggressive risk factor modification, with additional functional testing often guiding decisions for revacularisation^[5]. This makes reporting of coronary artery calcification critical and may enable immediate change in patient management.
 

While much less frequent, aortic valve calcification could be significant in up to a third of positive cases in this age group. Previous studies have shown that an aortic valve Agatston score above 150 may warrant echocardiographic evaluation, while a score above 500 should lead to echocardiographic assessment for aortic stenosis^[6]. 

This study demonstrates that visual scoring methods for coronary artery and aortic valve calcification can be used on unenhanced, non-gated CT chest examinations, and that these correlate with formal scoring methods. Similar to our result, excellent agreement between Ordial and Agatston scores for coronary artery calcium on nongated CT scan has previously been reported^[5].  

The main limitation of the study was the relatively small cohort in view of the high prevalence of coronary artery disease in the general population. However, this was sufficient to allow us to have an initial assessment of the patient cohort at our institution as well as to obtain significant results regarding the methods for quantification. Secondly, we could not control for acquisition parameters due to the retrospective nature of the study, but the majority of the studies were performed at a standard 120 kV.

The middle-aged adults in our study population underwent CT examination for a variety of indications and many had significant incidental coronary artery or aortic valve disease. By providing the referring physician with a severity score of the coronary artery and aortic valve calcification, further investigation may be prompted, which could lead to earlier intervention and improved outcomes for these patients. Given the increasing interest in preventive medicine, our result encourages routine reporting and quantification of coronary artery and aortic valve calcifications on non-ECG-gated CT chest examinations.