title: Quantitative analysis of coronary vessels with optimized intracoronary CT number.
abstract: BACKGROUND
  Variability in intracoronary computed tomography (CT) number may influence vessel quantification. We confirmed the feasibility of a novel method for measuring vessel diameter and area using coronary CT angiography (CCTA) with an optimized intracoronary CT number, 350 HU.
  
  
  METHODS
  We performed intravascular ultrasound (IVUS) imaging in 52 patients with significant stenosis detected by coronary CT angiography targeting 350 HU using a CT number-controlling system. We measured 0-to-0 HU distances in the cross-sectional coronary images of 32 patients. We analyzed the ratio of 0-to-0 HU distances in CT images to media-to-media distances in IVUS images (C:I ratio). The area of ≥0 HU for 103 representative points in the remaining 20 patients was compared to the area of the traced external elastic membrane (EEM) in IVUS images.
  
  
  RESULTS
  There was a strong correlation between 0-to-0 HU distance in CT images and media-to-media diameter in IVUS images (r = 0.97, p<0.001). The C:I ratio was 1.1. EEM area was estimated by dividing the area of ≥0 HU by the square of C:I. There was also a strong correlation between the estimated EEM area and the EEM area in IVUS images (r = 0.95, p<0.001).
  
  
  CONCLUSIONS
  Media-to-media diameter and EEM area can be estimated by CCTA targeting the optimized intracoronary CT number when blood vessel borders are defined at 0 HU.
authors.affiliation: Cardiovascular Center, Amagasaki Central Hospital, Hyogo, Japan.
authors.forename: Sei
authors.initials: S
authors.lastname: Komatsu
authors.affiliation: Department of Diagnostic Imaging, Amagasaki Central Hospital, Hyogo, Japan.
authors.forename: Teruaki
authors.initials: T
authors.lastname: Kamata
authors.affiliation: Cardiovascular Center, Amagasaki Central Hospital, Hyogo, Japan ; Department of Cardiology, Osaka University School of Medicine, Osaka, Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Imai
authors.affiliation: Cardiovascular Center, Amagasaki Central Hospital, Hyogo, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Ohara
authors.affiliation: Department of Diagnostic Imaging, Amagasaki Central Hospital, Hyogo, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Miyaji
authors.affiliation: Cardiovascular Center, Amagasaki Central Hospital, Hyogo, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Cardiovascular Center, Amagasaki Central Hospital, Hyogo, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Kodama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000209:etiology; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018084:Ultrasonography, Interventional / Q000379:methods*