Quantitative ultrasonography for assessment of bone mineral density in the canine radius and tibia.

Quantitative ultrasound allows noninvasive assessment of cortical bone density. Potential applications include monitoring of fracture healing, rehabilitation, and skeletal diseases. The objectives of this study were to determine the three most accessible portals to obtain speed of sound measurements of the radius and tibia with an Omnisense multisite quantitative ultrasound device and to determine probe-dependent intra- and interoperator variability for speed of sound measurements of the radius and tibia in six healthy hounds. The radius was most accessible at the cranial proximal metaphysis, the cranial middiaphysis, and medial distal metaphysis. Speed of sound measurements were possible at these sites on the radius with acceptable intra- and interoperator variation (1.6-4.6%). Measurements differed significantly when performed with different probes at the cranial proximal radial metaphysis. The tibia was most accessible at the cranial proximal metaphysis, the medial middiaphysis, and medial distal metaphysis. The medial middiaphyseal and mediodistal tibial sites allowed measurements with lowest intra- and interoperator variation (< 3.5%). A smaller probe allowed tibial measurements with lowest interoperator variation. Measurements did not differ significantly at each tibial site when different probes were used. Measurements did not differ significantly between observers when measuring with the same probe at each specific site on radius and tibia. A medium-size probe allowed for most time-efficient measurements and the least number of failed measurements on the radius and tibia. Speed of sound can be consistently measured by different observers on the radius and tibia in healthy hounds.