title: Intra- and interobserver reliability of gray scale/dynamic range evaluation of ultrasonography using a standardized phantom.
abstract: OBJECTIVE
  To evaluate intra- and interobserver reliability of the gray scale/dynamic range of the phantom image evaluation of ultrasonography using a standardized phantom, and to assess the effect of interactive education on the reliability.
  
  
  METHODS
  Three radiologists (a resident, and two board-certified radiologists with 2 and 7 years of experience in evaluating ultrasound phantom images) performed the gray scale/dynamic range test for an ultrasound machine using a standardized phantom. They scored the number of visible cylindrical structures of varying degrees of brightness and made a 'pass or fail' decision. First, they scored 49 phantom images twice from a 2010 survey with limited knowledge of phantom images. After this, the radiologists underwent two hours of interactive education for the phantom images and scored another 91 phantom images from a 2011 survey twice. Intra- and interobserver reliability before and after the interactive education session were analyzed using K analyses.
  
  
  RESULTS
  Before education, the K-value for intraobserver reliability for the radiologist with 7 years of experience, 2 years of experience, and the resident was 0.386, 0.469, and 0.465, respectively. After education, the K-values were improved (0.823, 0.611, and 0.711, respectively). For interobserver reliability, the K-value was also better after the education for the 3 participants (0.067, 0.002, and 0.547 before education; 0.635, 0.667, and 0.616 after education, respectively).
  
  
  CONCLUSIONS
  The intra- and interobserver reliability of the gray scale/dynamic range was fair to substantial. Interactive education can improve reliability. For more reliable results, double- checking of phantom images by multiple reviewers is recommended.
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Song
authors.identifier: 0000-0002-2367-3588
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Joon-Il
authors.identifier: 0000-0003-0018-8712
authors.initials: JI
authors.lastname: Choi
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Michael Yong
authors.identifier: 0000-0002-5247-1475
authors.initials: MY
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Dong Myung
authors.identifier: 0000-0002-1362-1362
authors.initials: DM
authors.lastname: Yeo
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Jae Young
authors.identifier: 0000-0002-0038-3860
authors.initials: JY
authors.lastname: Byun
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Seung Eun
authors.identifier: 0000-0003-0674-5444
authors.initials: SE
authors.lastname: Jung
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Sung Eun
authors.identifier: 0000-0003-1514-929X
authors.initials: SE
authors.lastname: Rha
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Soon Nam
authors.identifier: 0000-0003-2373-7024
authors.initials: SN
authors.lastname: Oh
authors.affiliation: Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Young Joon
authors.identifier: 0000-0001-8309-0272
authors.initials: YJ
authors.lastname: Lee
keywords: Health care quality assurance; Imaging phantoms; Reproducibility of results; Ultrasonography