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John C. Coleman
09-02-1993, 12:32 AM
I am currently conducting ultrasonic testing of small sections of cortical
bone to map the elastic moduli of a canine radius for use in the
construction of a finite element model. The calculations require values
for the apparent (structural) density of the bone, which I am measuring
simply by mass/volume of the bone specimens.

I would like to compare the densities that I am using to densities obtained
from an intact bone using quantitative CT data. But in order to do the
QCT, I need to obtain or prepare phantoms for a complete range of
densities--from 1.0 to 2.0 g/cm3. I have found reports (Genant et al.,
1981; Ruff, 1986;) of liquid phantom solutions containing dipotassium
hydrogen phosphate (K2HPO4) and ethyl alcohol, but have found no
description of the exact composition of these solutions. I am basically
looking for a "cookbook recipe" to prepare suitable liquid phantoms.

Other papers (Bentzen et al., 1987; Hvid et al., 1989) have reported the
use of acrylic phantoms while more recent reports indicate the use of solid
phantoms containing tricalcium phosphate and polymethyl methacrylate
(Snyder and Schneider, 1991). These phantoms provide a range of density
suitable for bone, but again only very brief mention is made of the
materials.

I would appreciate any information on the preparation of QCT phantoms and
the determination of apparent density (not bone mineral density) of
cortical bone using QCT methods. Any comments or suggestions on my
approach would also be greatly appreciated.

Thank you.

John C. Coleman
Department of Biomedical Engineering
Tulane University
New Orleans, LA 70118
Phone: (504) 865-5897
E-mail: johnc@bmen.tulane.edu