IEEE Trans Ultrason Ferroelectr Freq Control. 2020 Jun;67(6):1118-1126. doi: 10.1109/TUFFC.2020.2963955. Epub 2020 Jan 6.
The goal of this study was to develop an ultrasound (US) scatterer spacing estimation method using an enhanced cepstral analysis based on continuous wavelet transforms (CWTs). Simulations of backscattering media containing periodic and quasi-periodic scatterers were carried out to test the developed algorithm. Experimental data from HT-29 pellets and in vivo PC3 tumors were then used to estimate the mean scatterer spacing. For simulated media containing quasi-periodic scatterers at 1-mm and 100- [Formula: see text] spacing with 5% positional variation, the developed algorithm yielded a spacing estimation error of ~1% for 25- and 55-MHz US pulses. The mean scatterer spacing of HT-29 cell pellets (31.97 [Formula: see text]) was within 3% of the spacing obtained from histology and agreed with the predicted spacing from simulations based on the same pellets for both frequencies. The agreement extended to in vivo PC3 tumors estimation of the spacing with a variance of 1.68% between the spacing derived from the tumor histology and the application of the CWT to the experimental results. The developed technique outperformed the traditional cepstral methods as it can detect nonprominent peaks from quasi-random scatterer configurations. This work can be potentially used to detect morphological tissue changes during normal development or disease treatment.
本研究的目的是开发一种基于连续小波变换（CWT）的增强倒谱分析的超声（US）散射体间距估计方法。对包含周期性和准周期性散射体的背散射介质进行了模拟，以测试所开发的算法。然后使用 HT-29 微球和体内 PC3 肿瘤的实验数据来估计平均散射体间距。对于在 1-mm 和 100- [Formula: see text]间距处具有 5%位置变化的准周期性散射体的模拟介质，对于 25-和 55-MHz US 脉冲，所开发的算法的间距估计误差约为 1%。HT-29 细胞微球的平均散射体间距（31.97 [Formula: see text]）与组织学获得的间距相差 3%以内，并且与两种频率下基于相同微球的模拟预测间距一致。这一结果扩展到了体内 PC3 肿瘤的间距估计，肿瘤组织学得出的间距与将 CWT 应用于实验结果得出的间距之间的方差为 1.68%。与传统的倒谱方法相比，所开发的技术能够检测到来自准随机散射体配置的不明显峰值，因此具有更好的性能。这项工作可用于检测正常发育或疾病治疗过程中的组织形态变化。
