Identifying small coronary calcification in non-contrast 0.5-mm slice reconstruction to diagnose coronary artery disease in patients with a conventional zero coronary artery calcium score

Aims: in a new-generation computed tomography (ct) scanner,coronary artery calcium (cac) scores were measured using 3.0-mm slice reconstruction images originally acquired with 0.5 mm thickness scans in a single beat. this study investigated the usefulness of thin-slice (0.5 mm) reconstruction for identifying small calcifications in coronary arteries and evaluated the association with coronary plaques and stenosis compared to conventional 3.0-mm reconstruction images. methods: we evaluated 132 patients with zero cac scores in conventional 3.0-mm agatston method using a 320-slice ct. then,0.5-mm slice reconstruction was performed to identify small calcifications. the presence of stenosis and coronary plaques was assessed using coronary ct angiography. results: in total,22 small calcifications were identified in 18 patients. there were 28 (21%) patients with any (≥ 25%) stenosis (34 lesions). forty-seven coronary plaques were found in 33 patients (25%),including 7 calcified plaques in 7 patients (5%),34 noncalcified plaques in 27 patients (20%),and 6 partially calcified plaques in 5 patients (4%). patients with small calcifications had a significantly higher prevalence of noncalcified or partially calcified plaques (83% vs 14%; p＜0.001) and obstructive stenosis (33% vs 5.2%; p＜0.001) compared to those without small calcifications. the addition of small calcifications to the coronary risk factors when diagnosing stenosis significantly improved the diagnostic value. conclusion: small calcifications detected by thin-slice 0.5-mm reconstruction are useful for distinguishing coronary atherosclerotic lesions in patients with zero cac scores from conventional ct reconstruction. © 2016 japan atherosclerosis society.