title: Detection of small vessels with electron beam computed tomographic angiography using 1.5 and 3 mm collimator protocols.
abstract: OBJECTIVE
  To evaluate the effect of scanner collimation on the ability to detect small cardiac vessels using electron beam CT coronary angiography (EBA).
  
  
  METHODS
  EBA scans from 40 patients who underwent study on two separate occasions with 3 mm (initial scan) and 1.5 mm (follow-up scan) collimation protocols were analyzed. Vessels of <2 mm in diameter were identified.
  
  
  RESULTS
  The 1.5 mm collimation allowed 3-D visualization of 129 vessels<2 mm in diameter, while 3 mm collimation only allowed visualization of 89 vessels (p<0.001). The right coronary artery branches and distal LAD segments though were not displayed satisfactorily in almost half of the 3-D studies with either protocol.
  
  
  CONCLUSIONS
  There was significant improvement in detection of small cardiac vessels with a 1.5 mm collimation EBA protocol compared to a 3 mm protocol. Both protocols though were insufficient for reliable visualization of the right coronary artery branches and distal LAD segments.
authors.affiliation: Division of Cardiology, Harbor-UCLA Research and Education Institute, Torrance, CA 90502, USA.
authors.forename: Songshou
authors.initials: S
authors.lastname: Mao
authors.forename: Jerold S
authors.initials: JS
authors.lastname: Shinbane
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Oudiz
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Flores
authors.forename: Alex
authors.initials: A
authors.lastname: Chau
authors.forename: Stephen
authors.initials: S
authors.lastname: Liu
authors.forename: Shaojun
authors.initials: S
authors.lastname: Wang
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Gao
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Budoff
mesh_terms: D017023:Coronary Angiography / Q000379:methods*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*