Linked Life Data

9868278

Source:http://linkedlifedata.com/resource/pubmed/id/9868278

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-3-16
pubmed:abstractText
Studies have indicated that quantitative ultrasound (QUS) variables may be influenced by the mechanical properties of bone which in turn are determined by bone's material and structural properties. However, from these studies it is unclear what role density, elasticity, and structure play in determining velocity. Eighteen defatted, 12-mm cubic trabecular bone specimens were cut from cadaveric specimens. Amplitude-dependent speed of sound (SOS) using a single point QUS system was assessed in three orthogonal axes. Magnetic resonance images were obtained, from which measures of apparent trabeuclar structure were derived. The specimens were nondestructively tested in compression along three orthogonal axes defined by the sides of the cubes. The elastic modulus (in the three directions) and the strength (in one direction) were determined. Trabecular BMD was measured by quantitative computed tomography. SOS varied significantly with direction of measurement, with the highest value in the axial direction (axial:1715 m/s, sagittal: 1662 m/second, and coronal: 1676 m/s). SOS of each of the three axes was generally associated with the various mechanical (r = 0.30-0.87), density (r = 0.81-0.93), and bone structural variables (0.3-0.8). However, after adjusting the SOS correlations by density, only the correlation with elasticity remained significant in the coronal direction. BMD alone explained 88-93% of variance in SOS whereas in the multivariate model, BMD plus elasticity and/or anisotropic variables explained 96-98% of the variance in SOS. Variability of SOS is explained mostly by density and to a small extent by elasticity or anisotropy. Since only 2-6% of the variance of the QUS measurement is not explained by density and elasticity, one could conclude that the remaining variance reflects other properties of bone or perhaps simply measurement error. Evidence that these other properties may be structure related is only found in the anisotropy of QUS parameter.
pubmed:keyword
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0171-967X
pubmed:author
pubmed:issnType
Print
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18-23
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Ultrasound velocity of trabecular cubes reflects mainly bone density and elasticity.
pubmed:affiliation
Osteoporosis and Arthritis Research Group, Department of Radiology, University of California, San Francisco, 505 Parnassus Avenue, M392, Box 0628, San Francisco, California 94143, USA.
pubmed:publicationType
Journal Article