title: Image quality of multiplanar reconstruction of pulmonary CT scans using adaptive statistical iterative reconstruction.
abstract: OBJECTIVE
  We investigated the image quality of multiplanar reconstruction (MPR) using adaptive statistical iterative reconstruction (ASIR).
  
  
  METHODS
  Inflated and fixed lungs were scanned with a garnet detector CT in high-resolution mode (HR mode) or non-high-resolution (HR) mode, and MPR images were then reconstructed. Observers compared 15 MPR images of ASIR (40%) and ASIR (80%) with those of ASIR (0%), and assessed image quality using a visual five-point scale (1, definitely inferior; 5, definitely superior), with particular emphasis on normal pulmonary structures, artefacts, noise and overall image quality.
  
  
  RESULTS
  The mean overall image quality scores in HR mode were 3.67 with ASIR (40%) and 4.97 with ASIR (80%). Those in non-HR mode were 3.27 with ASIR (40%) and 3.90 with ASIR (80%). The mean artefact scores in HR mode were 3.13 with ASIR (40%) and 3.63 with ASIR (80%), but those in non-HR mode were 2.87 with ASIR (40%) and 2.53 with ASIR (80%). The mean scores of the other parameters were greater than 3, whereas those in HR mode were higher than those in non-HR mode. There were significant differences between ASIR (40%) and ASIR (80%) in overall image quality (p<0.01). Contrast medium in the injection syringe was scanned to analyse image quality; ASIR did not suppress the severe artefacts of contrast medium.
  
  
  CONCLUSIONS
  In general, MPR image quality with ASIR (80%) was superior to that with ASIR (40%). However, there was an increased incidence of artefacts by ASIR when CT images were obtained in non-HR mode.
authors.affiliation: Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan. ohonda@radiol.med.osaka-u.ac.jp
authors.forename: O
authors.initials: O
authors.lastname: Honda
authors.forename: M
authors.initials: M
authors.lastname: Yanagawa
authors.forename: A
authors.initials: A
authors.lastname: Inoue
authors.forename: A
authors.initials: A
authors.lastname: Kikuyama
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: H
authors.initials: H
authors.lastname: Sumikawa
authors.forename: K
authors.initials: K
authors.lastname: Tobino
authors.forename: M
authors.initials: M
authors.lastname: Koyama
authors.forename: N
authors.initials: N
authors.lastname: Tomiyama
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003287:Contrast Media; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media