title: Model-based iterative reconstruction in ultra-low-dose pediatric chest CT: comparison with adaptive statistical iterative reconstruction.
abstract: OBJECTIVE
  To evaluate image quality and dose reduction of ultra-low-dose pediatric chest CT reconstructed with model-based iterative reconstruction (MBIR), as compared with adaptive statistical iterative reconstruction (ASIR).
  
  
  METHODS
  Fifty-seven patients (mean age 14 years, M:F=31:26) who underwent ultra-low-dose chest CT reconstructed with both MBIR and ASIR were enrolled in the study. The subjective and objective image qualities of both reconstruction techniques were assessed by 3 radiologists, and compared using statistical analysis. We also evaluated radiation dose of ultra-low-dose chest CT as well as degree of dose reduction in comparison to the prior CT (either standard dose or reduced dose protocol) available in 36 patients.
  
  
  RESULTS
  The image quality of MBIR was superior to ASIR both subjectively and objectively. While MBIR showed preserved diagnostic acceptability in 100%, ASIR showed 92% at mean 0.31 mSv (range, 0.13-0.57 mSv) ultra-low-dose CT. In the 36 patients who underwent the prior CT, mean decrease in size-specific dose estimate (SSDE) and dose length product (DLP) at ultra-low-dose CT was 88% (range, 34% - 98%) and 86% (range,42% - 99%), respectively.
  
  
  CONCLUSIONS
  MBIR significantly improves image quality, as compared to ASIR. Furthermore, MBIR facilitates diagnostically acceptable ultra-low-dose chest CT with nearly 90% less radiation.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hae Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: somatom25@hanmail.net.
authors.forename: So-Young
authors.initials: SY
authors.lastname: Yoo
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Tae Yeon
authors.initials: TY
authors.lastname: Jeon
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008962:Models, Theoretical; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: CT dose reduction; Iterative reconstruction; Model-based iterative reconstruction; Pediatric chest CT