title: [Dual-energy computed tomographic angiography of head and neck with dual-source computed tomography: image quality and radiation dose].
abstract: OBJECTIVE
  To investigate the image quality and radiation dose of dual-energy (DE) computed tomographic angiography (CTA) of head and neck.
  
  
  METHODS
  We retrospectively analyzed two groups of patients (both n=30) undergoing 64-slice spiral CTA of cervical and cranial regions with different scan protocols. The DE group was obtained with 140/80 kVp, 64/272 mAs, 0.6 pitch, 80 ml of contrast medium, and caudal-cranial scan orientation. The single-energy (SE) group was obtained with 120 kVp, 220 mAs, 1.2 pitch, 60 ml of contrast medium and cranial-caudal scan orientation. The image quality and radiation dose were compared. The attenuation values and noises were measured on transverse images at 4 different vessels (the distal part of common carotid artery and adjacent vein in same axial image; the M1 segment of middle cerebral artery and sigmoid sinus or confluence of sinus in same image) and two muscles: erector spinae presenting average soft tissue enhancement and supraspinatus muscle presenting regions of great artifact.
  
  
  RESULTS
  In cranial region the arterial enhancement and venous contamination were similar (P=0.1427,P=0.1116) . In cervical region the arterial enhancement was similar (P=0.9414) . DE group had significantly greater venous contamination (P<0.0001) , while the mean attenuation value of common carotid artery was still 127 Hu higher than that of jugular vein. No matter artifact of soft tissue was obvious or not, the noise of DE group was significantly less than that of SE group (both P<0.0001) , and the soft tissue enhancement was similar (P=0.0760,P=0.0793) . The radiation dose required for bone-subtraction angiography was significantly less in DE group than in SE group (P<0.0001) .
  
  
  CONCLUSIONS
  DE group has comparable image quality to SE group and less scan dose for bone-subtraction. DE-CTA has great potential in clinical application. "
authors.affiliation: Department of Radiology, PUMC Hospital, Beijing 100730, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.forename: Hua-dan
authors.initials: HD
authors.lastname: Xue
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Kai
authors.initials: K
authors.lastname: Xu
authors.forename: Yu-mei
authors.initials: YM
authors.lastname: Li
authors.forename: Zheng-yu
authors.initials: ZY
authors.lastname: Jin
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods*; D005260:Female; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging; D011829:Radiation Dosage; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*