title: Contrast-enhanced magnetic resonance angiography of the carotid arteries: influence of injection rates and volumes on arterial-venous transit time.
abstract: OBJECTIVE
  To assess the influence of injection rates and volumes on the arrival time of contrast material (CM) in the common carotid artery, the jugular vein and the resulting arterial-venous transit time. Additionally the relationship between injection parameters and the extent of a CM plateau was evaluated.
  
  
  METHODS
  In 60 patients a CM injection was necessary to investigate suspected cranial disease. All patients were prospectively assigned to 6 protocol groups with varying volumes of gadolinium dimeglumine (2, 10, 20 mL) and injection rates (0.5, 1, 2, 4 mL/s). Simultaneously to the CM injection, 50 repetitive transverse measurements (1/s) were acquired at the level of the common carotid artery. Based on the resulting signal-time curves, the arrival time of the contrast material in the common carotid artery and the jugular vein, the resulting arterial-venous transit time, the peak enhancement and the extent of a CM-plateau were calculated as a function of the injection parameters.
  
  
  RESULTS
  Smaller flow rates (0.5 mL/s) resulted in a longer arrival time in the common carotid artery (mean value 22,6 seconds +/- 2.3) and the jugular vein (mean value 32.6 seconds +/- 2.6) and resulted in longer arterial-venous transit time (mean value 10.1 second +/- 1.9). The volume showed no effect on these parameters. The peak arterial and venous signal intensity and a consistent CM-plateau after 50 seconds were dependent on the volume, but not on the injection rate.
  
  
  CONCLUSIONS
  The injection rate showed an influence to the arrival time in the common carotid artery and the jugular vein and also to the arterial-venous transit time. The injected volume only affected the extent of the contrast plateau. A flow rate of 1 to 2 mL/s and a minimum of 20 mL gadolinium dimeglumine are recommended to achieve optimal image quality without venous overlay.
authors.affiliation: Department of Diagnostic Radiology, University Hospital of Regensburg, Franz-Josef-Strauss-Allee 11 D- 93 042, Germany. thomas.herold@klinik.uni-regensburg.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Herold
authors.forename: Christian
authors.initials: C
authors.lastname: Paetzel
authors.forename: Markus
authors.initials: M
authors.lastname: Völk
authors.forename: Maike
authors.initials: M
authors.lastname: Bachthaler
authors.forename: Niels
authors.initials: N
authors.lastname: Zorger
authors.forename: Stefan
authors.initials: S
authors.lastname: Feuerbach
authors.forename: Michael
authors.initials: M
authors.lastname: Strotzer
authors.forename: Markus
authors.initials: M
authors.lastname: Lenhart
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017536:Carotid Artery, Common / Q000473:pathology*; D002561:Cerebrovascular Disorders / Q000175:diagnosis*; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004334:Drug Administration Schedule; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D007275:Injections, Intravenous; D007601:Jugular Veins / Q000473:pathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA