title: Dynamic computed tomography of locally advanced pancreatic cancer: effect of low tube voltage and a hybrid iterative reconstruction algorithm on image quality.
abstract: OBJECTIVE
  The objective of this study was to evaluate the effect of a low-tube-voltage technique and hybrid iterative reconstruction (HIR) on image quality at dynamic computed tomography (CT) of the pancreas.
  
  
  METHODS
  The study included 18 consecutive patients (10 women, 8 men; mean age, 68.5 ± 9.5 years) with locally advanced pancreatic cancer who received chemotherapy and had stable disease during the 100- and 120-kV CT studies. The 120-kV images were reconstructed using filtered back projection, and the 100-kV images were postprocessed using filtered back projection and HIR. Scans obtained during 3 pancreatic phases were subjected to quantitative and qualitative analysis.
  
  
  RESULTS
  The mean effective dose was significantly lower under the 100- than the 120-kV protocols (29.2 ± 3.6 vs 52.1 ± 5.1 mSv; P < 0.01). The mean contrast-to-noise ratio of the pancreatic cancer and the visual scores were significantly higher under 100 kV with HIR than those under the other 2 protocols (P < 0.01).
  
  
  CONCLUSIONS
  Use of low tube voltage and HIR can provide significantly improved image quality at pancreatic dynamic CT.
authors.affiliation: From the Departments of *Diagnostic Radiology, †Medical Physics, and ‡Gastroenterological Surgery, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Sadahiro
authors.initials: S
authors.lastname: Yamamura
authors.forename: Seitaro
authors.initials: S
authors.lastname: Oda
authors.forename: Daisuke
authors.initials: D
authors.lastname: Utsunomiya
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Funama
authors.forename: Masanori
authors.initials: M
authors.lastname: Imuta
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Namimoto
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.forename: Akira
authors.initials: A
authors.lastname: Chikamoto
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D000465:Algorithms; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*