title: Determination of lowest possible contrast volume in computed tomography pulmonary angiography by using pulmonary transit time.
abstract: OBJECTIVE
  The aim of this study was to assess the effectiveness of the modified test-bolus (mTB) method in computed tomography pulmonary angiography (CTPA).
  
  
  METHODS
  The Institutional Review Board approved this retrospective study. We reviewed 24 patients (nine men, 15 women; age range, 21-88 years) in whom CTPA was performed either by Bolus-Tracking (BT) (n = 12) or mTB (n = 12) methods. Pulmonary transit time (PTT) was used to determine scan delay time and contrast volume in the mTB group. The contrast volume, radiation dose, quantitative measures, and qualitative scores of enhancement were compared. The chi-squared test, Mann-Whitney U test, and κ statistics were used. The significance level was 0.05.
  
  
  RESULTS
  The effective dose (P = 0.028) and contrast volume (P < 0.001) was significantly lower in the mTB group than those in the BT group. The difference in the quantitative measures and qualitative scores of enhancement between groups was statistically insignificant (P = 0.729, P = 0.635, respectively). Significantly fewer artefacts were observed in the mTB group (P = 0.024).
  
  
  CONCLUSIONS
  By taking into account PTT, mTB appears to be a promising method for tailoring CTPA to the patient with the use of less contrast material and resulting in fewer artifacts.
authors.affiliation: Department of Radiology, School of Medicine, Gazi University, Besevler/Ankara, 06510, Turkey, koraykilic@yahoo.com.
authors.forename: Koray
authors.initials: K
authors.lastname: Kilic
authors.forename: Gonca
authors.initials: G
authors.lastname: Erbas
authors.forename: Murat
authors.initials: M
authors.lastname: Ucar
authors.forename: Koray
authors.initials: K
authors.lastname: Akkan
authors.forename: Nil
authors.initials: N
authors.lastname: Tokgoz
authors.forename: Mehmet
authors.initials: M
authors.lastname: Arac
authors.forename: Sedat
authors.initials: S
authors.lastname: Isik
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000502:physiology*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media