title: Thickness sensitivity of ultrasound velocity in long bone phantoms.
abstract: One approach to bone disease diagnosis such as osteoporosis is to measure the velocity of ultrasound propagating axially along long bones. In this study, the variation in velocity as a function of radial position was assessed using two polyvinyl chloride (PVC) bone phantoms with cross-sectional geometry similar to the human tibia but differing in medullary cavity diameter. Two ultrasonometers were used: these were a commercial device operating at a relatively high frequency (HF) of 1.25 MHz and a prototype low frequency (LF) device operating at approximately 200 kHz. The LF measurements showed a larger variation with radial position, with changes in velocity of up to 20% occurring around the phantom compared with changes of only 4% at most for HF. The LF velocity correlated strongly with local thickness (r(2) = 0.81) but HF velocity did not. The results demonstrate that LF measurements have a greatly enhanced thickness sensitivity. Using LF, it may therefore be possible to assess bone thickness as a function of radial position and hence to determine the distribution of bone around the long axis.
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Finland. pemoilan@cc.jyu.fi
authors.forename: Petro
authors.initials: P
authors.lastname: Moilanen
authors.forename: Vantte
authors.initials: V
authors.lastname: Kilappa
authors.forename: Patrick H F
authors.initials: PH
authors.lastname: Nicholson
authors.forename: Jussi
authors.initials: J
authors.lastname: Timonen
authors.forename: Sulin
authors.initials: S
authors.lastname: Cheng
mesh_terms: D001842:Bone and Bones / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D010024:Osteoporosis / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D011143:Polyvinyl Chloride; D013977:Tibia / Q000033:anatomy & histology; D014465:Ultrasonics; D014463:Ultrasonography
chemical_list: D011143:Polyvinyl Chloride