title: [Dual-energy computed tomographic angiography of head and neck arteries with different contrast material doses in second generation dual-source computed tomography system].
abstract: OBJECTIVE
  To explore the feasibility of a dual-energy computed tomographic angiography (DECTA) protocol using test-bolus injection with reduction of contrast material (CM) dose in second generation dual-source CT system.
  
  
  METHODS
  Totally 57 consecutive patients underwent CT angiography scan covering the cervical and cerebral arteries. CT was performed with second generation dual-source CT system. The time to peak (T) using a test-bolus injection was calculated. The patients were divided into three groups (A, B, and C) with different CM doses (40, 45, and 50 ml) and different delay time points [ (T+1) , (T+1) , and (T+2) s] . All the patients were followed by a 48 ml saline flush. Arterial enhancements were quantified by measuring attenuation values of the aortic arch, bifurcation of common carotid artery, contralateral internal jugular vein of the CM injection, superior vein cava, proximal middle cerebral artery, basilar artery, and straight sinus on source images. Visualizations of intracranial artery and ipsilateral venous effect of the CM injection were rated on a four-point grading scale on CTA images for qualitative assessment.
  
  
  RESULTS
  Although the attenuation of internal jugular vein and straight sinus were significantly lower in group A than in groups B and C (P<0.05) , the attenuation of aortic arch, superior vein cava, common carotid artery, middle cerebral artery, and basilar artery vessels showed no significant differences among these three groups. The scores of the visualizations of intracranial artery and ipsilateral venous effect of the CM injection were also not significantly different among these three groups.
  
  
  CONCLUSIONS
  Based on the delay time calculated by a test-bolus injection, a reduced-dose contrast material may provide an equal degree of arterial attenuation and a lower attenuation of vein for dual-energy CTA covering the craniocervical region in second generation dual-source CT system.
authors.affiliation: Department of Radiology, PUMC Hospital, Beijing 100730, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Hua-dan
authors.initials: HD
authors.lastname: Xue
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.forename: Bai-yan
authors.initials: BY
authors.lastname: Su
authors.forename: Cuan
authors.initials: C
authors.lastname: Duo
authors.forename: Wei-di
authors.initials: WD
authors.lastname: Ming
authors.forename: Jie
authors.initials: J
authors.lastname: De
authors.forename: Bing
authors.initials: B
authors.lastname: Ji
authors.forename: Ji-xiang
authors.initials: JX
authors.lastname: Liang
authors.forename: Zheng-yu
authors.initials: ZY
authors.lastname: Jin
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D005240:Feasibility Studies; D005260:Female; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media