title: Prediction of aortic enhancement on coronary CTA images using a test bolus of diluted contrast material.
abstract: OBJECTIVE
  The purpose of our study was to compare test bolus techniques using undiluted or diluted contrast material for their ability to predict aortic enhancement on coronary computed tomographic angiography (c-CTA) images.
  
  
  METHODS
  We divided 200 consecutive patients who underwent c-CTA on a 64-MDCT scanner into two groups. In group A (n = 100), we used a test bolus of undiluted contrast material and in group B (n = 100), the contrast material was diluted. The injection volume was body weight × 0.2 (contrast material 100%) in group A and body weight × 0.7 (contrast material 30%, saline 70%) in group B. We then compared the CT number in the ascending aorta on c-CTA images obtained with undiluted and diluted contrast media to the CT number on c-CTA images.
  
  
  RESULTS
  The mean CT number in the ascending aorta was significantly higher in group B than group A (217.1 vs. 157.4 HU, P < .001). There was a significant difference in the correlation between the CT number of the ascending aorta on c-CTA images and on images acquired with the test bolus using undiluted or diluted test bolus (P < .001). In group B, the correlation had a strong positive linear relationship (r = 0.72, P < .001), whereas in group A the positive linear relationship was weak (r = 0.36).
  
  
  CONCLUSIONS
  The test bolus with diluted contrast material was useful for predicting aortic enhancement before c-CTA scanning.
authors.affiliation: Department of Radiological Technology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, Hiroshima 730-8655, Japan; Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan. Electronic address: takanorimasuda@yahoo.co.jp.
authors.forename: Takanori
authors.initials: T
authors.lastname: Masuda
authors.affiliation: Department of Medical Physics, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Funama
authors.affiliation: Department of Radiological Technology, Tsuchiya General Hospital, Nakajima-cho 3-30, Naka-ku, Hiroshima 730-8655, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Imada
authors.affiliation: Department of Diagnostic Radiology, Tsuchiya General Hospital, Hiroshima Japan.
authors.forename: Tomoyasu
authors.initials: T
authors.lastname: Sato
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Yamagami
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Fuminari
authors.initials: F
authors.lastname: Tatsugami
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol
keywords: Test bolus technique; aortic enhancement; contrast material; coronary CTA