title: Adaptive Iterative Dose Reduction Using Three Dimensional Processing (AIDR3D) improves chest CT image quality and reduces radiation exposure.
abstract: OBJECTIVE
  To assess the advantages of Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D) for image quality improvement and dose reduction for chest computed tomography (CT).
  
  
  METHODS
  Institutional Review Boards approved this study and informed consent was obtained. Eighty-eight subjects underwent chest CT at five institutions using identical scanners and protocols. During a single visit, each subject was scanned using different tube currents: 240, 120, and 60 mA. Scan data were converted to images using AIDR3D and a conventional reconstruction mode (without AIDR3D). Using a 5-point scale from 1 (non-diagnostic) to 5 (excellent), three blinded observers independently evaluated image quality for three lung zones, four patterns of lung disease (nodule/mass, emphysema, bronchiolitis, and diffuse lung disease), and three mediastinal measurements (small structure visibility, streak artifacts, and shoulder artifacts). Differences in these scores were assessed by Scheffe's test.
  
  
  RESULTS
  At each tube current, scans using AIDR3D had higher scores than those without AIDR3D, which were significant for lung zones (p<0.0001) and all mediastinal measurements (p<0.01). For lung diseases, significant improvements with AIDR3D were frequently observed at 120 and 60 mA. Scans with AIDR3D at 120 mA had significantly higher scores than those without AIDR3D at 240 mA for lung zones and mediastinal streak artifacts (p<0.0001), and slightly higher or equal scores for all other measurements. Scans with AIDR3D at 60 mA were also judged superior or equivalent to those without AIDR3D at 120 mA.
  
  
  CONCLUSIONS
  For chest CT, AIDR3D provides better image quality and can reduce radiation exposure by 50%.
authors.affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Yamashiro
authors.affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Miyara
authors.affiliation: Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Honda
authors.affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kamiya
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohno
authors.affiliation: Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tomiyama
authors.affiliation: Department of Radiology, Ohara General Hospital, Fukushima-shi, Fukushima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriya
authors.affiliation: Department of Radiology, Osaka Medical College, Takatsuki, Osaka, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Koyama
authors.affiliation: Department of Radiology, Tenri Hospital, Tenri, Nara, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Noma
authors.affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Ayano
authors.initials: A
authors.lastname: Kamiya
authors.affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan; Center for Clinical Training, Fujieda Municipal General Hospital, Fujieda, Shizuoka, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Murayama
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D013902:Radiography, Thoracic / Q000379:methods*