title: Bolus timing in high-pitch CT angiography of the aorta.
abstract: OBJECTIVE
  To investigate the bolus geometry in high-pitch CT angiography (CTA) of the aorta without ECG synchronisation in comparison to single-source CT.
  
  
  METHODS
  Overall 160 consecutive patients underwent CTA either in conventional single-source mode with a pitch of 1.2 (group 1), or in dual-source mode with a pitch of 3.0 (groups 2, 3 and 4) using different contrast media timings with bolus triggering at 140 HU (5s, group 1; 10s, group 2; 12s, group 3; 14s, group 4). Contrast material, saline flush, flow rate and kV/mAs settings were kept equal for optimum comparability. Aortic attenuation was measured along the z-axis of the patient at different anatomic landmarks and subjective image quality was compared.
  
  
  RESULTS
  The most homogeneous enhancement of the aorta was reached with a delay of 10s after reaching the trigger threshold. The imaging length was not significantly different, but the examination time was significantly (p<0.001) shorter in the high-pitch group (7.7s vs. 1.7s for group 1 vs. 2, 3 and 4).
  
  
  CONCLUSIONS
  In high-pitch CT angiography using a start delay of 10s after a trigger threshold of 140 HU in the descending aorta is reached, a homogenous contrast along the z-axis is accomplished.
authors: Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany. beeres@gmx.net
authors: Martin
authors: M
authors: Beeres
authors: Matthias
authors: M
authors: Loch
authors: Boris
authors: B
authors: Schulz
authors: Matthias
authors: M
authors: Kerl
authors: Firas
authors: F
authors: Al-Butmeh
authors: Boris
authors: B
authors: Bodelle
authors: Eva
authors: E
authors: Herrmann
authors: Tatjana
authors: T
authors: Gruber-Rouh
authors: Clara
authors: C
authors: Lee
authors: Volkmar
authors: V
authors: Jacobi
authors: Thomas J
authors: TJ
authors: Vogl
authors: Ralf W
authors: RW
authors: Bauer
mesh_terms: D000328:Adult; D000368:Aged; D001018:Aortic Diseases / Q000000981:diagnostic imaging*; D001027:Aortography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media