title: Controlling intracoronary CT number for coronary CT angiography.
abstract: BACKGROUND
  Controlling intracoronary computed tomography (CT) number for coronary CT angiography (CCTA) has been difficult.
  
  
  OBJECTIVE
  The study assessed whether intracoronary CT number of CCTA could be estimated.
  
  
  METHODS
  One hundred twenty six patients were randomly assigned to either CCTA with 30 mL of contrast media (CM) following 5 mL of CM at timing bolus or CCTA with 50 mL of CM following 10 mL of CM at timing bolus. The relationships between intracoronary CT number and patients' characteristics and peak time and peak CT number at timing bolus in patients who showed valid time-density curve were analyzed in both groups. Then, the multiple regression equation best described was made. The prediction system was validated by 112 patients randomly targeted between 250 HU and 430 HU of CT number.
  
  
  RESULTS
  In group 5/30, intracoronary CT number was positively correlated with peak CT number at timing bolus (correlation coefficient, 1.42, p<0.001), negatively correlated with body surface area (-109.19, p<0.001) and peak time (-6.93, p<0.001). Whereas, intracoronary CT number was positively correlated with only peak CT number at timing bolus (1.33, p<0.001) in group 10/50. Then, CT number-controlling system using the simple equation best described CT number was established for CCTA following 5 mL of CM at timing bolus. Of 112 patients, there was good correlation between target CT number and measured CT number (r=0.85, p<0.0001) in 96 patients (85.7%), having valid time-density curve at timing bolus.
  
  
  CONCLUSIONS
  Controlling CT number may be enabled by CT number-controlling system following 5 mL of CM at timing bolus.
authors.affiliation: Cardiovascular Center, Amagasaki Central Hospital, Hyogo, Japan. plaquemap@yahoo.co.jp
authors.forename: Sei
authors.initials: S
authors.lastname: Komatsu
authors.forename: Teruaki
authors.initials: T
authors.lastname: Kamata
authors.forename: Atsuko
authors.initials: A
authors.lastname: Imai
authors.forename: Tomoki
authors.initials: T
authors.lastname: Ohara
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Takewa
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Miyaji
authors.forename: Junichi
authors.initials: J
authors.lastname: Yoshida
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Kodama
mesh_terms: D000465:Algorithms; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods* / Q000592:standards; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011446:Prospective Studies
chemical_list: D003287:Contrast Media