title: Cerebral computed tomography angiography using a 70 kVp protocol: improved vascular enhancement with a reduced volume of contrast medium and radiation dose.
abstract: OBJECTIVE
  To determine the feasibility of using a 70-kVp protocol compared with a 120-kVp protocol for cerebral CT angiography. An additional target was to investigate a possible reduction in the volume of contrast medium (CM) using the 70-kVp protocol.
  
  
  METHODS
  Attenuation value and CNR for iodine were determined at various tube voltage settings using a phantom. Sixty-nine volunteers were randomly assigned to one of three protocols: group A (120-kVp and CM 64 mL), group B (70-kVp and CM 64 mL), or group C (70-kVp and CM 40 mL). The attenuation value, SNR, and CNR of cerebral arteries, subjective image quality, and radiation dose were compared among the groups.
  
  
  RESULTS
  The vascular attenuation, SNR, and CNR of group B were significantly higher than those of group A. Group C had a significantly higher vascular attenuation than group A. Groups B and C were significantly better than group A with respect to subjective image quality. An effective dose of 70-kVp was 10 % lower than that of 120-kVp.
  
  
  CONCLUSIONS
  Using 70-kVp improved arterial enhancement, SNR, and CNR, and provided better subjective image quality, using a 10 % lower effective dose. Furthermore, the 70-kVp protocol may both reduce volume of CM by 37.5 % and improve arterial enhancement.
  
  
  CONCLUSIONS
  • Cerebral CT angiography at 70-kVp substantially improved vascular enhancement • Subjective image quality was better at 70-kVp, with lower radiation dose • The volume of contrast media can be substantially reduced at 70-kVp.
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, 211 Eonjuro, Gangnam-gu, Seoul, 135-720, Korea.
authors.forename: Eun-Suk
authors.initials: ES
authors.lastname: Cho
authors.forename: Tae-Sub
authors.initials: TS
authors.lastname: Chung
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Ahn
authors.forename: KyoungHoon
authors.initials: K
authors.lastname: Chong
authors.forename: Jang Hun
authors.initials: JH
authors.lastname: Baek
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Suh
mesh_terms: D000328:Adult; D002533:Cerebral Angiography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007455:Iodine; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D012016:Reference Values; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide; D007455:Iodine