title: ACRIN CT colonography trial: does reader's preference for primary two-dimensional versus primary three-dimensional interpretation affect performance?
abstract: OBJECTIVE
  To determine whether the reader's preference for a primary two-dimensional (2D) or three-dimensional (3D) computed tomographic (CT) colonographic interpretation method affects performance when using each technique.
  
  
  METHODS
  In this institutional review board-approved, HIPAA-compliant study, images from 2531 CT colonographic examinations were interpreted by 15 trained radiologists by using colonoscopy as a reference standard. Through a survey at study start, study end, and 6-month intervals, readers were asked whether their interpretive preference in clinical practice was to perform a primary 2D, primary 3D, or both 2D and 3D interpretation. Readers were randomly assigned a primary interpretation method (2D or 3D) for each CT colonographic examination. Sensitivity and specificity of each method (primary 2D or 3D), for detecting polyps of 10 mm or larger and 6 mm or larger, based on interpretive preference were estimated by using resampling methods.
  
  
  RESULTS
  Little change was observed in readers' preferences when comparing them at study start and study end, respectively, as follows: primary 2D (eight and seven readers), primary 3D (one and two readers), and both 2D and 3D (six and six readers). Sensitivity and specificity, respectively, for identifying examinations with polyps of 10 mm or larger for readers with a primary 2D preference (n = 1128 examinations) were 0.84 and 0.86, which was not significantly different from 0.84 and 0.83 for readers who preferred 2D and 3D (n = 1025 examinations) or from 0.76 and 0.82 for readers with a primary 3D preference (n = 378 examinations). When performance by using the assigned 2D or 3D method was evaluated on the basis of 2D or 3D preference, there was no difference among those readers by using their preferred versus not preferred method of interpretation. Similarly, no significant difference among readers or preferences was seen when performance was evaluated for detection of polyps of 6 mm or larger.
  
  
  CONCLUSIONS
  The reader's preference for interpretive method had no effect on CT colonographic performance.
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic, 13400 E Shea Blvd, Scottsdale, AZ 85259, USA. hara.amy@mayo.edu
authors.forename: Amy K
authors.initials: AK
authors.lastname: Hara
authors.forename: Meridith
authors.initials: M
authors.lastname: Blevins
authors.forename: Mei-Hsiu
authors.initials: MH
authors.lastname: Chen
authors.forename: Abraham H
authors.initials: AH
authors.lastname: Dachman
authors.forename: Mark D
authors.initials: MD
authors.lastname: Kuo
authors.forename: Christine O
authors.initials: CO
authors.lastname: Menias
authors.forename: Bettina
authors.initials: B
authors.lastname: Siewert
authors.forename: Jugesh I
authors.initials: JI
authors.lastname: Cheema
authors.forename: Richard G
authors.initials: RG
authors.lastname: Obregon
authors.forename: Jeff L
authors.initials: JL
authors.lastname: Fidler
authors.forename: Peter
authors.initials: P
authors.lastname: Zimmerman
authors.forename: Karen M
authors.initials: KM
authors.lastname: Horton
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Coakley
authors.forename: Revathy B
authors.initials: RB
authors.lastname: Iyer
authors.forename: Robert A
authors.initials: RA
authors.lastname: Halvorsen
authors.forename: Giovanna
authors.initials: G
authors.lastname: Casola
authors.forename: Judy
authors.initials: J
authors.lastname: Yee
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Herman
authors.forename: C Daniel
authors.initials: CD
authors.lastname: Johnson
mesh_terms: D001291:Attitude of Health Personnel; D002983:Clinical Competence; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D012984:Software; D011795:Surveys and Questionnaires