title: Estimation of in vivo cortical bone thickness using ultrasonic waves.
abstract: OBJECTIVE
  To verify the measurement of cortical bone thickness at the distal radius in vivo using an ultrasonic method.
  
  
  METHODS
  The method for estimating cortical bone thickness was derived from experiments with in vitro bovine specimens. Propagation time of echo waves and propagation time of slow waves were used for the estimation. The outside diameter of cortical bone and the cortical bone thickness at the distal 5.5 % site of radius were measured with the new ultrasonic bone measurement system, and the results were compared with X-ray pQCT clinical measurements.
  
  
  RESULTS
  There was a high positive correlation (r: 0.76) between the cortical bone thickness measured by the new ultrasonic system and the X-ray pQCT results.
  
  
  CONCLUSIONS
  We will be able to measure not only cancellous bone density but also cortical bone thickness in vivo using ultrasonic waves (without X-ray) safely and repeatedly.
authors.affiliation: Office for Research Initiatives and Development, Doshisha University, Kyotanabe, 610-0321, Kyoto, Japan. imano@mail.doshisha.ac.jp.
authors.forename: Isao
authors.initials: I
authors.lastname: Mano
authors.affiliation: Oyo Electric Co., Ltd., Joyo, 610-0101, Kyoto, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Horii
authors.affiliation: Faculty of Medicine, Tottori University, Yonago, 683-0826, Tottori, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hagino
authors.affiliation: Izumiotsu Municipal Hospital, Izumiotsu, 595-0027, Osaka, Japan.
authors.forename: Takami
authors.initials: T
authors.lastname: Miki
authors.affiliation: Faculty of Science and Engineering, Doshisha University, Kyotanabe, 610-0321, Kyoto, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Matsukawa
authors.affiliation: Faculty of Science and Engineering, Doshisha University, Kyotanabe, 610-0321, Kyoto, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Otani
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D002417:Cattle; D006801:Humans; D066298:In Vitro Techniques; D009929:Organ Size; D011884:Radius / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014463:Ultrasonography
keywords: Cortical bone thickness; Distal radius; Fast and slow waves; pQCT