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Bone Density Virgina Oncology Associates
Several methods are available to measure bone density,
but currently the most widely used technique is DEXA (Dual
Energy Xray Absorptiometry). This is the method used to
determine efficacy in the recent large clinical trials,
and to characterize fracture risk in large epidemiological
studies. Older methods such as single photon absorptiometry
do not predict hip fractures as well as DEXA. Three companies
manufacture these densitometers: Hologic, Norland, and
Lunar.
Newer techniques such as ultrasound appear to offer
a more cost-effective method of screening bone mass.
Ultrasound measurements are usually performed at the
calcaneous and it is not possible to measure sites of
osteoporotic fracture such as the hip or spine. Adding
an ultrasound measurement to a DEXA does not improve
the prediction of fractures. Although some have said
that ultrasound measures the "quality" of
bone, more careful studies suggest that it mainly measures
the bone mass.
Several techniques can measure bone density at the hand,
radius or ankle. These include single energy absorptiometry,
metacarpal width or density from hand xrays. Magnetic
resonance imaging is a new method of measuring bone
density.
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