Dencks Stefanie, Barkmann Reinhard, Padilla Frédéric, Laugier Pascal, Schmitz Georg, Glüer Claus-C
Department of Diagnostic Radiology, University Hospital Schleswig-Holstein, Kiel, Germany.
IEEE Trans Ultrason Ferroelectr Freq Control. 2008;55(6):1304-15. doi: 10.1109/TUFFC.2008.793.
To improve the prediction of the osteoporotic fracture risk at the proximal femur we are developing a scanner for quantitative ultrasound (QUS) measurements at this site. Due to multipath transmission in this complex shaped bone, conventional signal processing techniques developed for QUS measurements at peripheral sites frequently fail. Therefore, we propose a model-based estimation of the QUS variables and analyze the performance of the new algorithm. Applying the proposed method to QUS scans of excised proximal femurs increased the fraction of evaluable signals from approx. 60% (using conventional algorithms) to 97%. The correlation of the standard QUS variables broadband ultrasound attenuation (BUA) and speed of sound (SOS) with the established variable bone mineral density (BMD) reported in previous studies is maintained (BUA/BMD: r(2) = 0.69; SOS/BMD: r(2) = 0.71; SOS+BUA/BMD: r(2) = 0.88). Additionally, different wave types could be clearly detected and characterized in the trochanteric region. The ability to separate superimposed signals with this approach opens up further diagnostic potential for evaluating waves of different sound paths and wave types through bone tissue.
为了提高对股骨近端骨质疏松性骨折风险的预测，我们正在研发一种用于该部位定量超声（QUS）测量的扫描仪。由于在这种形状复杂的骨骼中存在多径传输，为外周部位QUS测量开发的传统信号处理技术常常失效。因此，我们提出了一种基于模型的QUS变量估计方法，并分析了新算法的性能。将所提出的方法应用于切除的近端股骨的QUS扫描，可将可评估信号的比例从约60%（使用传统算法）提高到97%。先前研究中报道的标准QUS变量宽带超声衰减（BUA）和声速（SOS）与既定变量骨矿物质密度（BMD）之间的相关性得以保持（BUA/BMD：r² = 0.69；SOS/BMD：r² = 0.71；SOS+BUA/BMD：r² = 0.88）。此外，在转子区可以清晰地检测和区分不同的波型。用这种方法分离叠加信号的能力为评估通过骨组织的不同声路和波型的波开辟了进一步的诊断潜力。
