title: Low radiation dose computed tomography coronary angiography: evaluation of the variations in coronary arteries.
abstract: OBJECTIVE
  Despite attempts to decrease the radiation dose, coronary computed tomography angiography (CCTA) generally uses higher doses than computed tomography scans of other organs. The purpose of this study was to evaluate the incidence of the variations of the coronary arteries using the adaptive statistical iterative reconstruction technique to perform low-dose coronary computed tomography (CTA).
  
  
  METHODS
  Diagnostic CCTA scans were performed in 3433 patients (from November 2010 to January 2015) using an Optima CT660 (GE Healthcare, USA) 64-slice and analyzed retrospectively.
  
  
  RESULTS
  The mean effective dose was 2.1 mSv (1.2-4.9 mSv) for prospective and 4.5 mSv (3.6-9.1 mSv) for retrospective ECG-gated scans. The variations of the coronary arteries (CA) excluding myocardial bridge (MB) were detected in 76 (2.2 %) of the 3433 patients. A myocardial bridge was the most common variation (n = 288, 8.3 %). The second most common variation (n = 13, 17.1 %) was an absence of the left main coronary artery (LMCA) with separate starting points for the left anterior descending (LAD) and left circumflex (LCX) arteries. In addition, there was a rare variation (n = 1, 1.3 %) consisting of the LAD artery originating from the right coronary artery (RCA).
  
  
  CONCLUSIONS
  The present retrospective study was conducted using CCTA on patients with a coronary artery variations in Turkey (n = 3433). Our data show that low-dose CCTA can be used to detect common coronary variations.
authors.affiliation: Radiology, Bahar Hospital, Kibris sehitleri cad. No: 179 Osmangazi, Bursa, Turkey. drndogan@gmail.com.
authors.forename: Nurullah
authors.initials: N
authors.lastname: Dogan
authors.affiliation: Cardiology, Bahar Hospital, Bursa, Turkey.
authors.forename: Aydin
authors.initials: A
authors.lastname: Dursun
authors.affiliation: Department of Cardiology, Bahcesehir University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Ozkan
authors.affiliation: Radiology, Bahar Hospital, Kibris sehitleri cad. No: 179 Osmangazi, Bursa, Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Karataş
authors.affiliation: Cardiology, Bahar Hospital, Bursa, Turkey.
authors.forename: Nuran
authors.initials: N
authors.lastname: Celiloglu
authors.affiliation: Cardiology, Yuksek Ihtisas Training and Research Hospital, Bursa, Turkey.
authors.forename: Fahriye Vatansever
authors.initials: FV
authors.lastname: Agca
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D063405:Anatomic Variation; D000072226:Computed Tomography Angiography / Q000379:methods*; D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000528:radiation effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D012189:Retrospective Studies; D014421:Turkey; D055815:Young Adult
keywords: Angiography; Coronary artery variation; Coronary computed tomography angiography