title: Isotropic chest CT examination: diagnostic quality of reformats.
abstract: OBJECTIVE
  To evaluate the image quality of axial and coronal reformats obtained from isotropic resolution 40-channel chest computed tomography (CT) examinations.
  
  
  METHODS
  Thirty consecutive patients with intravenous contrast-enhanced chest CT examinations using a 40-channel CT machine were enrolled for the study. The raw data were reconstructed into two sets of source axial images: 0.9 mm section width and 0.45 mm reconstruction interval (isotropic resolution) and 4mm section width with 3 mm reconstruction interval (anisotropic resolution; group A). The isotropic data set was reformatted into axial and coronal stacks (groups B and C, respectively) with 4 mm section width and 3 mm interval. Three independent readers evaluated stacks A to C using a three-point scale for resolution of right lower lobe segmental bronchi, edge sharpness of major and minor fissures, respiratory motion artefact, reconstruction artefact, noise and overall image quality.
  
  
  RESULTS
  The sharpness of fissures scored significantly higher with the coronal reformats (group C) compared with the axial image sets (groups A and B) (p<0.01). Noise in group A scored significantly lower than groups B or C (p<0.01). For other parameters there was no statistical difference between the groups. There was substantial or excellent agreement between the reviewers.
  
  
  CONCLUSIONS
  Isotropic imaging of the chest allows creation of reformats with similar image quality as similar thickness axial source images. These reformats are probably of sufficient quality to form the basis of clinical interpretation.
authors.affiliation: Department of Radiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: J
authors.initials: J
authors.lastname: Rydberg
authors.forename: K
authors.initials: K
authors.lastname: Sandrasegaran
authors.forename: J
authors.initials: J
authors.lastname: Ying
authors.forename: F
authors.initials: F
authors.lastname: Akisik
authors.forename: R H
authors.initials: RH
authors.lastname: Choplin
authors.forename: R D
authors.initials: RD
authors.lastname: Tarver
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007479:Iopamidol; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D013902:Radiography, Thoracic / Q000592:standards*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000592:standards*
chemical_list: D003287:Contrast Media; D007479:Iopamidol