Format

Send to

Choose Destination
See comment in PubMed Commons below
Phys Med Biol. 2011 Oct 7;56(19):6243-55. doi: 10.1088/0031-9155/56/19/006. Epub 2011 Sep 6.

Effect of the cortex on ultrasonic backscatter measurements of cancellous bone.

Author information

  • 1Department of Physics, Rhodes College, Memphis, TN, USA. hoffmeister@rhodes.edu

Abstract

Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

PMID:
21896966
PMCID:
PMC3535011
DOI:
10.1088/0031-9155/56/19/006
[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for IOP Publishing Ltd. Icon for PubMed Central
    Loading ...
    Support Center