title: Feasibility Study of Radiation Dose Reduction in Adult Female Pelvic CT Scan with Low Tube-Voltage and Adaptive Statistical Iterative Reconstruction.
abstract: OBJECTIVE
  To evaluate image quality of female pelvic computed tomography (CT) scans reconstructed with the adaptive statistical iterative reconstruction (ASIR) technique combined with low tube-voltage and to explore the feasibility of its clinical application.
  
  
  METHODS
  Ninety-four patients were divided into two groups. The study group used 100 kVp, and images were reconstructed with 30%, 50%, 70%, and 90% ASIR. The control group used 120 kVp, and images were reconstructed with 30% ASIR. The noise index was 15 for the study group and 11 for the control group. The CT values and noise levels of different tissues were measured. The contrast to noise ratio (CNR) was calculated. A subjective evaluation was carried out by two experienced radiologists. The CT dose index volume (CTDIvol) was recorded.
  
  
  RESULTS
  A 44.7% reduction in CTDIvol was observed in the study group (8.18 ± 3.58 mGy) compared with that in the control group (14.78 ± 6.15 mGy). No significant differences were observed in the tissue noise levels and CNR values between the 70% ASIR group and the control group (p = 0.068-1.000). The subjective scores indicated that visibility of small structures, diagnostic confidence, and the overall image quality score in the 70% ASIR group was the best, and were similar to those in the control group (1.87 vs. 1.79, 1.26 vs. 1.28, and 4.53 vs. 4.57; p = 0.122-0.585). No significant difference in diagnostic accuracy was detected between the study group and the control group (42/47 vs. 43/47, p = 1.000).
  
  
  CONCLUSIONS
  Low tube-voltage combined with automatic tube current modulation and 70% ASIR allowed the low CT radiation dose to be reduced by 44.7% without losing image quality on female pelvic scan.
authors.affiliation: Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Xinlian
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Wen
authors.initials: W
authors.lastname: He
authors.affiliation: Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Jianghong
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Zhihai
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Liqin
authors.initials: L
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D005240:Feasibility Studies; D005260:Female; D005831:Genital Diseases, Female / Q000175:diagnosis / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed
keywords: Adaptive statistical iterative reconstruction; CT; Radiation dose; Tube-voltage