title: Diagnostic efficacy of vessel specific coronary calcium score in detection of coronary artery stenosis.
abstract: BACKGROUND
  Coronary artery calcification which is determined quantitatively by coronary calcium scoring has been known as a sign of coronary stenosis and thus future cardiac events; hence it has been noticed on spotlight of researchers in recent years. Developing different method for early and optimal detection of coronary artery disease (CAD) is really essential as CAD are the first cause of death in population.
  
  
  OBJECTIVE
  To evaluate predictive value of vessel specific coronary artery calcium (CAC) score in predicting obstructive coronary artery disease.
  
  
  METHODS
  In this diagnostic test study we evaluated patients with coronary computed tomography angiography (CCTA) and CAC score which had been referred to two referral radiology center in Tehran, Iran and finally we selected 2525 patients in a single and sequential pattern to create a diagnostic study. The whole-heart CAC scores and vessel specific CAC scores were calculated individually for the 4 major epicardial coronary arteries in 2 distinct group; group A ( patients with previous history of CABG) and group B (patients without history of CABG). For evaluation of obstruction tree cut off points were described: 0 > ; at least 1 segment with any kind of stenosis, ≥ 50; at least 1 segment with stenosis ≥ 50, ≥ 70; at least 1 segment with stenosis ≥ 70.
  
  
  RESULTS
  Mean of coronary calcium scores in terms of each coronary artery vessel increase by increasing coronary stenosis grade in group B; LAD, RCA, LCX respectively have mean CAC score 6.06, 6.21 and 5.04 in normal patients and 221.6, 226.7 and 106.6 in patients with complete stenosis. As expected these findings don't work for group A. Also By increasing calcium score cutoff in all four vessels sensitivity decreased and specificity increased but steal LAD had higher sensitivity than other vessels and LM had higher specificity. Thus using calcium score method is useful for ruling out stenosis in LAD while calcium score of LM can predict existence of stenosis in LM. However none of the vessel specific CAC can reach to 100% sensitivity and specificity of CCTA method.
  
  
  CONCLUSIONS
  CCTA is highly superior than vessel specific CAC score thus to minimize patients radiation does maybe we can eliminate CAC scan as a routinely perform procedure at the beginning of the CCTA.
authors.affiliation: Department of Radiology, Shahid Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Motevalli
authors.affiliation: Department of Radiology, Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Ghanaati
authors.affiliation: Department of Radiology, Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Kavous
authors.initials: K
authors.lastname: Firouznia
authors.affiliation: Department of Radiology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Jalal
authors.initials: J
authors.lastname: Kargar
authors.affiliation: Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mounes
authors.initials: M
authors.lastname: Aliyari Ghasabeh
authors.affiliation: Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mona
authors.initials: M
authors.lastname: Shahriari
authors.affiliation: Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Amir Hosein
authors.initials: AH
authors.lastname: Jalali
authors.affiliation: Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, IR Iran.
authors.forename: Madjid
authors.initials: M
authors.lastname: Shakiba
keywords: Computed Tomography; Coronary Angiography; Coronary Artery Disease