A CONTACT METHOD FOR THE ASSESSMENT OF ULTRASONIC VELOCITY AND BROAD-BAND ATTENUATION IN CORTICAL AND CANCELLOUS BONE

A portable system using a direct contact method for the measurement of ultrasonic velocity and broadband attenuation in bone is described (contact ultrasonic bone analyser, CUBA). Soft-tissue compensation is performed using an ultrasonic pulse-echo technique. CUBA has been successfully validated using reference materials, the precision of velocity and broadband attenuation measurements being typically 0.2% and 0.5% respectively. The clinical reproducibility has been assessed on the equine third metacarpal bone. The reproducibility of velocity measurement is typically 0.5% for cortical bone and 1% for cancellous bone. For broadband attenuation the reproducibility is typically 7% for cortical bone and 6% for cancellous bone. The lower reproducibility of the attenuation data is attributed to the high sensitivity to variations in the material properties of bone with small changes in transducer positioning. Coupling difficulties through an intact equine coat have been overcome and the system may be assessed in the clinical environment, in both human and animal populations.