title: 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.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Urabe
authors.forename: Hideya
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Toshiro
authors.initials: T
authors.lastname: Kitagawa
authors.forename: Hiroto
authors.initials: H
authors.lastname: Utsunomiya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsushima
authors.forename: Fuminari
authors.initials: F
authors.lastname: Tatsugami
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Kihara
mesh_terms: D002114:Calcinosis / Q000503:physiopathology*; D002118:Calcium / Q000378:metabolism*; D000072226:Computed Tomography Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D061205:Vascular Calcification / Q000503:physiopathology*
chemical_list: D002118:Calcium