title: Radiation dose reduction using 100-kVp and a sinogram-affirmed iterative reconstruction algorithm in adolescent head CT: Impact on grey-white matter contrast and image noise.
abstract: OBJECTIVE
  To retrospectively evaluate the image quality and radiation dose of 100-kVp scans with sinogram-affirmed iterative reconstruction (IR) for unenhanced head CT in adolescents.
  
  
  METHODS
  Sixty-nine patients aged 12-17 years underwent head CT under 120- (n = 34) or 100-kVp (n = 35) protocols. The 120-kVp images were reconstructed with filtered back-projection (FBP), 100-kVp images with FBP (100-kVp-F) and sinogram-affirmed IR (100-kVp-S). We compared the effective dose (ED), grey-white matter (GM-WM) contrast, image noise, and contrast-to-noise ratio (CNR) between protocols in supratentorial (ST) and posterior fossa (PS). We also assessed GM-WM contrast, image noise, sharpness, artifacts, and overall image quality on a four-point scale.
  
  
  RESULTS
  ED was 46% lower with 100- than 120-kVp (p < 0.001). GM-WM contrast was higher, and image noise was lower, on 100-kVp-S than 120-kVp at ST (p < 0.001). CNR of 100-kVp-S was higher than of 120-kVp (p < 0.001). GM-WM contrast of 100-kVp-S was subjectively rated as better than of 120-kVp (p < 0.001). There were no significant differences in the other criteria between 100-kVp-S and 120-kVp (p = 0.072-0.966).
  
  
  CONCLUSIONS
  The 100-kVp with sinogram-affirmed IR facilitated dramatic radiation reduction and better GM-WM contrast without increasing image noise in adolescent head CT.
  
  
  CONCLUSIONS
  • 100-kVp head CT provides 46% radiation dose reduction compared with 120-kVp. • 100-kVp scanning improves subjective and objective GM-WM contrast. • Sinogram-affirmed IR decreases head CT image noise, especially in supratentorial region. • 100-kVp protocol with sinogram-affirmed IR is suited for adolescent head CT.
authors.affiliation: Department of Radiology, Kumamoto City Hospital, 1-1-60, Koto, Higashi-ku, Kumamoto, 862-0909, Japan. y.nagayama1980@gmail.com.|Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan. y.nagayama1980@gmail.com.
authors.forename: Yasunori
authors.identifier: http://orcid.org/0000-0003-3280-7346
authors.initials: Y
authors.lastname: Nagayama
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakaura
authors.affiliation: Department of Radiology, Kumamoto City Hospital, 1-1-60, Koto, Higashi-ku, Kumamoto, 862-0909, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Tsuji
authors.affiliation: Department of Radiology, Kumamoto City Hospital, 1-1-60, Koto, Higashi-ku, Kumamoto, 862-0909, Japan.
authors.forename: Joji
authors.initials: J
authors.lastname: Urata
authors.affiliation: Department of Radiology, Kumamoto City Hospital, 1-1-60, Koto, Higashi-ku, Kumamoto, 862-0909, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Furusawa
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yuki
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Hirarta
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kidoh
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Seitaro
authors.initials: S
authors.lastname: Oda
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Utsunomiya
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000293:Adolescent; D000465:Algorithms; D016477:Artifacts; D002648:Child; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D066127:White Matter / Q000000981:diagnostic imaging*
keywords: Computed tomography X-ray; Cranial irradiation; Image processing; Paediatrics; Radiation protection