title: Prediction of aortic peak enhancement in monophasic contrast injection protocols at multidetector CT: phantom and patient studies.
abstract: OBJECTIVE
  The aim of this study was to investigate whether it is possible to predict aortic peak enhancement (APE) from the contrast dose and injection rate.
  
  
  METHODS
  We first undertook an experimental study using a flow phantom that simulates the human circulation. We delivered 90-150 ml of iomeprol-350 at various injection rates and measured the APE values of the simulated aorta. In our clinical study we randomized 20 patients into four groups. In groups A, B, and C the iodine dose per kilogram of body weight (BW) ranged from 450 to 600 mg, and the injection duration was fixed at 30 s; group D received 450 mg/kg over 25 s. We then measured APE in all patients at the whole aorta, averaged the three highest values, and took the result as APE.
  
  
  RESULTS
  In the phantom study, the decision coefficient for the best-fit equation obtained by multiple regression analysis of the relation between the iodine dose and injection rate and the simulated APE was high (0.93). In the patient study, the predicted APE values almost corresponded with the averaged APE values when we applied the fitness equation.
  
  
  CONCLUSIONS
  Using our fitness equation, APE on contrast-enhanced computed tomography can be predicted from the iodine dose and the contrast injection rate per patient weight.
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan. awai@kaiju.medic.kumamoto-u.ac.jp
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakaura
authors.forename: Yumi
authors.initials: Y
authors.lastname: Yanaga
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tamura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hatemura
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Funama
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001011:Aorta; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007267:Injections; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D011446:Prospective Studies; D012044:Regression Analysis; D036542:Tomography, Spiral Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol