title: Image Settings Affecting Nuchal Translucency Measurement Using Volume NT Software.
abstract: OBJECTIVE
  To evaluate the effects of the deviation from the mid-sagittal plane, fetal image size, tissue harmonic imaging (THI), and speckle reduction filter (SRF) on the measurement of the nuchal translucency (NT) thickness using Volume NT software.
  
  
  METHODS
  In 79 pregnant women, NT was measured using Volume NT. Firstly, the three-dimensional volumes were categorized based on the angle of deviation in 10° intervals from the mid-sagittal plane. Secondly, the operator downsized the fetal image to less than 50% of the screen (Method A) and by magnifying the image (Method B). Next, the image was magnified until the fetal head and thorax occupied 75% of the screen, and the NT was measured (Method C). Lastly, NT values were acquired with THI and SRF functions on, with each function alternately on, and with both functions off.
  
  
  RESULTS
  The mean differences in NT measurements were -0.09 mm (p<0.01) between two-dimensional (2D) and a deviation of 31-40° and -0.10 mm (p<0.01) between 2D and 41-50°. The intraclass correlation coefficients (ICC) for 2D-NT and NT according to image size were 0.858, 0.923, and 0.928 for methods A, B, and C, respectively. The ICC for 2D-NT and NT with respect to the THI and SRF were 0.786, 0.761, 0.740, and 0.731 with both functions on, THI only, SRF only, and with both functions off, respectively.
  
  
  CONCLUSIONS
  NT measurements made using Volume NT are affected by angle deviation from the mid-sagittal plane and fetal image size. Additionally, the highest correlation with 2D-NT was achieved when THI and SRF functions were used.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Institute of Women's Life Medical Science, Yonsei University College of Medicine, Yonsei University Health System, Seoul, Korea.
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Cho
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Institute of Women's Life Medical Science, Yonsei University College of Medicine, Yonsei University Health System, Seoul, Korea.
authors.forename: Young Han
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Institute of Women's Life Medical Science, Yonsei University College of Medicine, Yonsei University Health System, Seoul, Korea.
authors.forename: Yong Won
authors.initials: YW
authors.lastname: Park
authors.affiliation: Samsung Medison Research and Development Center, Seoul, Korea.
authors.forename: Sung Yoon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Samsung Medison Research and Development Center, Seoul, Korea.
authors.forename: Kwang Hee
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Samsung Medison Research and Development Center, Seoul, Korea.
authors.forename: Joon Sang
authors.initials: JS
authors.lastname: Yoo
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Institute of Women's Life Medical Science, Yonsei University College of Medicine, Yonsei University Health System, Seoul, Korea. jaykwon@yuhs.ac.
authors.forename: Ja-Young
authors.initials: JY
authors.lastname: Kwon
mesh_terms: D000328:Adult; D004622:Embryo, Mammalian / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D048208:Nuchal Translucency Measurement / Q000379:methods; D011247:Pregnancy; D012680:Sensitivity and Specificity; D012984:Software
keywords: Volume NT™ software; angle deviation; image size; nuchal translucency; speckle reduction filter; tissue harmonic imaging