title: Choosing the best reconstruction technique in abdominal computed tomography: a systematic approach.
abstract: OBJECTIVE
  There is uncertainty regarding the effect of iterative reconstruction (IR) techniques and other reconstruction algorithms on image quality. The aim of this study was to optimize image quality in relation to radiation dose in computed tomography (CT) liver examinations by comparing images reconstructed with different abdominal filters with and without IR.
  
  
  METHODS
  An anthropomorphic phantom was scanned on a Toshiba Aquilion ONE CT scanner. Images at 2 different dose levels were reconstructed with 12 different body reconstruction filters, all with both filtered back-projection and Adaptive Iterative Dose Reduction 3 dimensional. Receiver operating characteristic curves were constructed. The 2 reconstruction combinations with the highest scores from the phantom study were evaluated in a second comparison of clinical images. Six liver examinations were reconstructed with both filters and evaluated using visual grading analysis.
  
  
  RESULTS
  Two combinations of reconstruction filters and IR were the only 2 options among the 8 best images at both dose levels (area under the curve, 0.96 and 0.94 for 15 mGy as well as 0.86 and 0.84 for 10 mGy). In the patient study, one of these filters in combination with IR scored slightly higher than the other in combination with IR (mean score, 2.60 and 2.57, respectively; P = 0.56). Iterative reconstruction did not significantly increase lesion detectability for any of the filters.
  
  
  CONCLUSIONS
  This study indicates that the preferred choice for reconstruction of CT liver examinations performed with the Toshiba Aquilion ONE should be the FC18 filter with IR, although the IR technique did not significantly improve lesion detectability and did not compensate for the dose reduction in this study.
authors.affiliation: From *The Intervention Centre, Oslo University Hospital; †Department of Physics, University in Oslo; ‡Department of Radiology and Nuclear Medicine, Oslo University Hospital, Rikshospitalet; and §Department of Medicine, University in Oslo, Oslo, Norway.
authors.forename: Hilde Kjernlie
authors.initials: HK
authors.lastname: Andersen
authors.forename: Kristin
authors.initials: K
authors.lastname: Jensen
authors.forename: Audun Elnaes
authors.initials: AE
authors.lastname: Berstad
authors.forename: Trond Mogens
authors.initials: TM
authors.lastname: Aaløkken
authors.forename: Joanna
authors.initials: J
authors.lastname: Kristiansen
authors.forename: Bjørn
authors.initials: B
authors.lastname: von Gohren Edwin
authors.forename: Gaute
authors.initials: G
authors.lastname: Hagen
authors.forename: Anne Catrine Trægde
authors.initials: AC
authors.lastname: Martinsen
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging*; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*