title: Assessment of vascular contrast and wall motion of the aortic root and ascending aorta on MDCT angiography: dual-source high-pitch vs non-gated single-source acquisition schemes.
abstract: OBJECTIVE
  This retrospective study assessed whether dual-source high-pitch computed tomographic angiography (CTA) offered advantages over single-source standard-pitch techniques in the evaluation of the ascending aorta.
  
  
  METHODS
  Twenty patients who received both thoracic dual-source high-pitch and single-source standard-pitch CTAs within 1 year were assessed. Dual-source CTAs were performed; standard-pitch imaging used dose-modulated 120 kVp/150 mAs and 0.8 pitch compared with high-pitch protocols employing dose-modulated 120 kVp/250 mAs and 2.4 target pitch. Radiation dose was documented. Contrast-to-noise ratios (CNRs) at sinuses of the Valsalva (CNRValsalva) and ascending aorta (CNRAorta) were calculated. Dose/CNR for each technique was compared with paired t-tests. Motion at aortic valve, aortic root and ascending aorta were assessed with four-point scales and Mann-Whitney U tests; longitudinal extension of motion was compared with paired t-tests.
  
  
  RESULTS
  Significantly lower motion scores for high-pitch, compared with standard-pitch acquisitions for aortic annulus, 0 vs. 2, aortic root, 0 vs. 3, and ascending aorta, 0 vs. 2, were achieved. Significantly reduced longitudinal extension of motion at aortic root, 4.9 mm vs 15.7 mm, and ascending aorta, 4.9 mm vs 21.6 mm, was observed. Contrast was not impacted: CNRValsalva, 45.6 vs 46.3, and CNRAorta, 45.3 vs 47.1. CTDIvol was significantly decreased for high-pitch acquisitions, 13.9 mGy vs 15.8 mGy.
  
  
  CONCLUSIONS
  Dual-source high-pitch CTAs significantly decreased motion artefact without negatively impacting vascular contrast and radiation dose.
  
  
  CONCLUSIONS
  • Dual-source high-pitch CTA significantly decreased motion artefact of the ascending aorta. • Dual-source high-pitch CTA did not negatively impact on vascular contrast. • Dual-source high-pitch CTA significantly decreased radiation dose compared with single-source standard-pitch acquisitions.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC, 27710, USA.
authors.forename: Jared D
authors.initials: JD
authors.lastname: Christensen
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Seaman
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Lungren
authors.forename: Lynne M
authors.initials: LM
authors.lastname: Hurwitz
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Boll
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods*; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000502:physiology; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000502:physiology; D016477:Artifacts; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D011829:Radiation Dosage; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult