title: [Assessment of a matrix-based quantitative ultrasound imaging device (Beam scanner): reproducibility].
abstract: OBJECTIVE
  A new matrix-based quantitative ultrasound (QUS) device was developed for the assessment of two parameters: BUA (Broadband Ultrasound Attenuation) and SOS (Speed Of Sound). This device, called Beam scanner, is a contact imaging device designed to evaluate the calcaneus. The aim of this preliminary study was to evaluate the reproducibility of results in a sample of patient with heterogeneous age distribution.
  
  
  METHODS
  Seventy-six subjects were included: 18 healthy young males, 18 healthy young women and 40 women aged over 50 years old, including 19 osteoporotic patients according to WHO criteria. Five measurements were made for each patient after foot repositioning. Short-term precision was estimated using the coefficient of variation (CV), standardized CV (SCV) and intra-class correlation coefficient (ICC).
  
  
  RESULTS
  SCV varied with the group of subjects between 2.0 and 4.3% for BUA, and between 3.1 and 4.5% for SOS. Mean values of BUA and SOS were statistically lower for osteoporotic women compared with healthy young women or healthy young males (p<0.001). For BUA, only SCV and ICC were better for women aged over 50 years old but without statistical difference.
  
  
  CONCLUSIONS
  This study shows that the heterogeneity of the studied sample population is not a significant factor when assessing precision. This new device has a precision similar to others QUS devices.
authors.affiliation: GIP Ultrasons/Laboratoire d'UltrasonS Signaux et Images EA 2022, Université de Tours. magomez@caramail.com
authors.forename: M A
authors.initials: MA
authors.lastname: Gomez
authors.forename: M
authors.initials: M
authors.lastname: Nasser-Eddin
authors.forename: M
authors.initials: M
authors.lastname: Defontaine
authors.forename: B
authors.initials: B
authors.lastname: Giraudeau
authors.forename: F
authors.initials: F
authors.lastname: Jacquot
authors.forename: F
authors.initials: F
authors.lastname: Patat
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D002111:Calcaneus / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation* / Q000592:standards; D008297:Male; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000295:instrumentation / Q000592:standards