Autocorrelation and cepstral methods for measurement of tibial cortical thickness
Autocorrelation and cepstral methods for measurement of tibial cortical thickness
复制标题
用于测量胫骨皮质厚度的自相关和倒谱方法
DOI：
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发表时间：
2003
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通讯作者：
K. Wear
中科院分区：
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作者：
K. Wear
胫骨皮质厚度与应力性骨折风险和整体骨骼状况有关。提出了两种方法估计胫骨皮质厚度的功率谱的超声回波包含反射从前面和后面的皮质。自相关函数和倒谱中的峰值的位置与皮质厚度有关。在塑料板上获得数据以验证方法。这些数据表明估计厚度和真实厚度之间的高度相关性，自相关法的相关系数r=0.99（95%置信区间：0.993-1.00），倒谱法的相关系数r=0.99（95% CI：0.996-1.00）。6个胫骨样本的体外数据表明，自相关法的相关系数r=0.92（95% CI：0.72-1.00），倒谱法的相关系数r=0.85（95% CI：0.62-0.94）。两种方法的精密度估计值分别为0.3/spl plusmn/0.1 mm（自相关法）和0.5/spl plusmn/0.2 mm（倒谱法）。在人体志愿者体内进行的一次测量证明了测量的临床可行性，并且与使用外周定量计算机断层扫描（QCT）评估的皮质厚度具有良好的一致性。这项技术提供了一种廉价，快速，便携，简单，非电离技术评估骨骼状态的承诺。
Cortical thickness of the tibia is related to stress fracture risk and overall skeletal status. Two methods are proposed for estimating tibial cortical thickness based on power spectra of ultrasonic echoes containing reflections from front and back surfaces of the cortex. The locations of the peaks in the autocorrelation function and the cepstrum are related to cortical thickness. Data were acquired on plastic plates in order to validate the methodology. These data indicate high correlations between estimated and true thickness with correlation coefficients r=0.99, (95% confidence interval: 0.993-1.00) for the autocorrelation method and r=0.99 (95% CI: 0.996-1.00) for the cepstral method. Data on six tibia samples in vitro indicate correlation coefficients of r=0.92 (95% CI: 0.72-1.00) for the autocorrelation method and r=0.85 (95% CI: 0.62-0.94) for the cepstral method. Estimates of precisions of the two methods were 0.3/spl plusmn/0.1 mm (autocorrelation method) and 0.5/spl plusmn/0.2 mm (cepstral method). One measurement in a human volunteer in vivo demonstrated clinical feasibility of the measurement and good agreement with cortical thickness assessed using peripheral quantitative computed tomography (QCT). This technology offers the promise of an inexpensive, fast, portable, simple, nonionizing technique for assessing skeletal status.