title: High-pitch dual-source CT angiography of supra-aortic arteries: assessment of image quality and radiation dose.
abstract: BACKGROUND
  High-pitch CT angiography (CTA) is a recent innovation that allows significant shortening of scan time with volume coverage of 43 mm per second. The aim of our study was to assess this technique in CTA of the head and neck.
  
  
  METHODS
  CTA of supra-aortic arteries was performed in 50 patients using two acquisition protocols: conventional single-source 64-slice (pitch 1.2) and high-pitch dual-source 128-slice CT (pitch 3.2). Subjective and objective image quality of supra-aortic vessel ostia as well as intra- and extra-cranial segments was retrospectively assessed by blinded readers and radiation dose compared between the two protocols.
  
  
  RESULTS
  Conventional and high-pitch CTA achieved comparable signal-to-noise ratios in arterial (54.3 ± 16.5 versus 57.3 ± 14.8; p = 0.50) and venous segments (15.8 ± 6.7 versus 18.9 ± 8.9; p = 0.21). High-pitch scanning was, however, associated with sharper delineation of vessel contours and image quality significantly improved at the level of supra-aortic vessel ostia (p < 0.0001) as well as along the brachiocephalic trunk (p < 0.0001), the subclavian arteries (p < 0.0001), proximal common carotid arteries (p = 0.01), and vertebral V1 segments (p < 0.0001). Using the high-pitch mode, the dose-length product was reduced by about 35% (218.2 ± 30 versus 141.8 ± 20 mGy × cm).
  
  
  CONCLUSIONS
  Due to elimination of transmitted cardiac motion, high-pitch CTA of the neck improves image quality in the proximity of the aortic arch while significantly lowering radiation dose. The technique thus qualifies as a promising alternative to conventional spiral CTA and may be particularly useful for identification of ostial stenosis.
authors.affiliation: Department of Diagnostic und Interventional Neuroradiology, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Korn
authors.forename: M
authors.initials: M
authors.lastname: Fenchel
authors.forename: B
authors.initials: B
authors.lastname: Bender
authors.forename: S
authors.initials: S
authors.lastname: Danz
authors.forename: C
authors.initials: C
authors.lastname: Thomas
authors.forename: D
authors.initials: D
authors.lastname: Ketelsen
authors.forename: C D
authors.initials: CD
authors.lastname: Claussen
authors.forename: G
authors.initials: G
authors.lastname: Moonis
authors.forename: B
authors.initials: B
authors.lastname: Krauss
authors.forename: M
authors.initials: M
authors.lastname: Heuschmid
authors.forename: U
authors.initials: U
authors.lastname: Ernemann
authors.forename: H
authors.initials: H
authors.lastname: Brodoefel
mesh_terms: D000368:Aged; D000465:Algorithms; D000792:Angiography / Q000379:methods*; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D001822:Body Burden; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*