Quantitative Ultrasound (QUS) techniques for the assessment of bone fragility
The fragility of the human skeleton is an important risk factor for osteoporotic fractures. Today, (radiologically measured) bone density measurements (DXA) serve as a surrogate for bone fragility, not taking into account other important aspects like material strength or structure. On the other hand, ultrasound measurement techniques have been applied successfully in medical diagnosis as well as material testing. With our research we aim to exploit the full potential of ultrasound measurements for the assessment of bone properties to improve diagnosis, risk assessment, and monitoring of bone status.
By combining own developments in ultrasonics, mechanics and electronics we build and test new devices for laboratory as well as in vivo research applications. For the first time we could measure the proximal femur with QUS in vivo showing a performance at least as good as with standard methods. Current research on the propagation of guided waves through compact bone shall lead to a further improved fragility measurement of the femur by including measurements at the femoral neck and proximal shaft.
Another application of guided waves is the axial transmission measurement at long bones for an improved estimation of bone material properties. By additionally measuring the ultrasound propagation in tangential direction we are able to calculate the anisotropy of the mid-tibia aiming at an enhanced assessment of cortical bone properties like porosity.
The reduction of precision errors can improve the ability of QUS to monitor the progress of bone fragility due to disease or therapy. Several measures have been applied to reduce precision errors in calcaneal QUS.