Assessment of bone status using speed of sound at multiple anatomical sites

Njeh, C.F; Saeed, I; Grigorian, M; Kendler, D.L; Fan, B; Shepherd, J; McClung, M; Drake, W.M; Genant, H.K

« Previous Next »Ultrasound in Medicine and Biology
Volume 27, Issue 10 , Pages 1337-1345, October 2001

Assessment of bone status using speed of sound at multiple anatomical sites

C.F Njeh
- Address correspondence to: Christopher F. Njeh, Ph.D., Osteoporosis and Arthritis Research Group, Department of Radiology, University of California San Francisco, 350 Parnassus Avenue, Suite 607, San Francisco, CA 94143-1349, USA
- Department of Radiology, University of California, San Francisco, San Francisco, CA, USA
I Saeed
- Department of Radiology, University of California, San Francisco, San Francisco, CA, USA
M Grigorian
- Department of Radiology, University of California, San Francisco, San Francisco, CA, USA
D.L Kendler
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
B Fan
- Department of Radiology, University of California, San Francisco, San Francisco, CA, USA
J Shepherd
- Department of Radiology, University of California, San Francisco, San Francisco, CA, USA
M McClung
- Oregon Osteoporosis Center, Department of Medicine, Portland, OR, USA
W.M Drake
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
H.K Genant
- Department of Radiology, University of California, San Francisco, San Francisco, CA, USA

Received 26 February 2001; accepted 28 June 2001.

Abstract

Studies in vitro and in vivo have shown that quantitative ultrasound (QUS) is a valid tool for the assessment of bone status. Current QUS methods using the transmission technique are limited to one peripheral bone site. A new system, Sunlight Omnisense™ (Omnisense, Sunlight Medical Ltd., Rehovot, Israel), measures speed of sound (SOS, in m/s) along the surface of the bone based on an axial transmission technique. The Omnisense™ can measure SOS at several anatomical sites. This study evaluated the SOS at different anatomical sites in a healthy population. A total of 334 adult women from three research centers in the USA and Canada with a mean (± SD) age of 48.8 (± 17.4) years were enrolled in this study. SOS was measured at the proximal third phalanx, distal one third radius, midshaft tibia, and fifth metatarsal. The mean SOS (± SD) values for the phalanx, radius, tibia and metatarsal were 3984 (± 221), 4087 (± 147), 3893 (± 150) and 3690 (± 246) m/s, respectively. Each anatomical site SOS was significantly different (p < 0.001) from that of the other sites. SOS at the different anatomical sites was modestly, but significantly, correlated (r = 0.31 to 0.56, p < 0.001). Similar correlation coefficients were obtained for the T scores. The mean T scores for subjects over the age of 60 years were −1.94, −2.01, −0.97 and −1.42 for the phalanx, radius, tibia and metatarsal, respectively. The age of peak SOS and the rate of change thereafter varied with anatomical site, implying that the prevalence of osteopenia and osteoporosis was site-dependent if only one T score cut-off point was used. Comparing individuals, 10% to 17% of patients had T scores that differed by more than a factor of 2 between sites. Weight and age were some of the contributing factors to this heterogeneity. The Omnisense™ provides an opportunity to assess bone status at different anatomical sites. Whether or not combining measurements from all these anatomical sites will improve osteoporosis management still needs to be determined. (E-mail: christopher.njeh@oarg.ucsf.edu)

Keywords: Bone density, Bone status, Osteoporosis, Quantitative ultrasound, Speed of sound, T scores