title: Effect of contrast medium injection duration on peak enhancement and time to peak enhancement of canine pulmonary arteries.
abstract: Our goal was to investigate the effect of contrast medium injection duration on pulmonary artery peak enhancement and time to peak enhancement. Fourteen dogs were allocated into one of seven predefined weight categories, each category contained two dogs. Dogs in each weight category were assigned to group A or B. Animals in each group received a different contrast medium injection protocol. In group A, a fixed injection rate of 5 ml/s was used. In group B, the contrast injection rate was calculated as follows: flow rate= contrast volume/scan duration + 10s. Time to peak enhancement and peak enhancement of the main left and right pulmonary arteries were measured on single-level, dynamic CT images for a fixed time of 30s. Rank correlation (Spearman's) coefficients between injection duration and time to peak enhancement and between body weight and peak enhancement were calculated. For group A, there was a significant negative correlation between peak enhancement and weight (r = -0.94; P = 0.005), while for group B, there was no significant correlation (r = -0.64 and P = 0.18). There was a significant correlation between time to peak enhancement and injection duration in both groups (group A: r = 0.99; P = 0.006 and group B: r = 0.85; P = 0.02). In conclusion, injection duration is a key feature in a CT angiography injection protocol. A protocol with an injection duration adjusted to the scan duration seems to be particularly suitable for veterinary applications where a population with great weight variability is studied.
authors.affiliation: Section of Diagnostic Imaging , Vetsuisse Faculty University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
authors.forename: Mariano
authors.initials: M
authors.lastname: Makara
authors.forename: Matthias
authors.initials: M
authors.lastname: Dennler
authors.forename: Karolin
authors.initials: K
authors.lastname: Kühn
authors.forename: Karin
authors.initials: K
authors.lastname: Kalchofner
authors.forename: Patrick
authors.initials: P
authors.lastname: Kircher
mesh_terms: D000792:Angiography / Q000379:methods* / Q000662:veterinary*; D000818:Animals; D001835:Body Weight; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004285:Dogs; D005260:Female; D008297:Male; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011897:Random Allocation; D013997:Time Factors; D014056:Tomography, X-Ray / Q000379:methods* / Q000662:veterinary*
chemical_list: D003287:Contrast Media