title: Multi-detector row CT of the head and neck: comparison of different volumes of contrast material with and without a saline chaser.
abstract: BACKGROUND
  The aim of this study was to determine the effect of different volumes of contrast material with and without a saline chaser on tissue enhancement in multidetector row CT (MDCT) of the head and neck.
  
  
  METHODS
  In a blind prospective fashion, 120 patients were randomized into the following four groups: group 1, 80 ml contrast material administered at a flow rate of 2.0 ml/s; group 2, 80 ml followed by 40 ml saline at 2.0 ml/s; group 3, 60 ml at 1.5 ml/s; and group 4, 60 ml followed by 30 ml saline at 1.5 ml/s. The attenuation values of the carotid artery, internal jugular vein, and muscle were measured at an interval of 1.5 s in each patient. The degree of perivenous artifacts was subjectively assessed.
  
  
  RESULTS
  Mean attenuation values in the carotid artery and internal jugular vein were significantly higher in groups 1 and 2 than in groups 3 and 4. The width of the diagnostic window (both carotid and jugular enhancement >150 HU) were significantly longer in groups 1 and 2 than in groups 3 and 4. The addition of a saline chaser did not result in improved vascular enhancement or a wider diagnostic window, but reduced perivenous artifacts, compared with using contrast material alone.
  
  
  CONCLUSIONS
  Reduction of contrast material from 80 to 60 ml results in insufficient enhancement of neck vessels. In addition, the benefit of a saline chaser technique is not obvious except for its ability to reduce perivenous artifacts.
authors.affiliation: Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, 445 Gil-dong Kangdong-Gu, Seoul 134-701, South Korea. evee0914@chollian.net
authors.forename: Dae Young
authors.initials: DY
authors.lastname: Yoon
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: You
authors.forename: Chul Soon
authors.initials: CS
authors.lastname: Choi
authors.forename: Suk Ki
authors.initials: SK
authors.lastname: Chang
authors.forename: Eun Joo
authors.initials: EJ
authors.lastname: Yun
authors.forename: Young Lan
authors.initials: YL
authors.lastname: Seo
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Park
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Lee
authors.forename: Jeung Hee
authors.initials: JH
authors.lastname: Moon
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Rho
authors.forename: Jin-Hwan
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000704:Analysis of Variance; D016477:Artifacts; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007472:Iohexol / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D012965:Sodium Chloride / Q000008:administration & dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; D012965:Sodium Chloride