Abstract:Carotid elastography can obtain the strain distribution of carotid atherosclerotic plaques and evaluate the
vulnerability of plaques. Spatial angular compounding (SAC) has been proposed to improve the performance of strain
estimation in carotid elastography. However, the motion and deformation of the plaque during multi-angle acquisitions may
cause motion artifacts. In this study, the factors introducing motion artifacts in the strain estimation, including the pulse
repetition frequency (PRF) and number of steering angle (NSA) were analyzed in the simulation experiments. In order to
mimic the motion and deformation of the plaque, a constant axial compression at the strain rate of 2 s-1 was applied during the
imaging process. The PRF was set from 0.2 kHz to 10 kHz and the NSA was set to 1, 3, 5 and 7. The elastographic signal-tonoise
ratio (SNR) and contrast-to-noise ratio (CNR) were used to quantitatively evaluate the quality of strain estimation. The
results showed that, the SNRs and CNRs increased with the PRF w hen PRF<4 kHz, and then remained constant. Comparing the
performance of NSA=3, 5 and 7, the SNRs and CNRs were higher with a smaller NSA when PRF<1 kHz. When PRF exceeded
4 kHz, the performance of SAC with different NSAs became similar in terms of SNRs and CNRs. In conclusion, this study has
investigated the influence of the PRF and NSA on motion artifacts of strain imaging with SAC. In carotid elastography with
SAC, the strain images with less motion artifacts are obtained when NSA is 3 and PRF>4 kHz.
潘宗辉,刘志,李富峰,何琼. 空间角度复合应变估计中的运动伪影产生因素研究[J]. 中国医疗设备, 2019, 34(5): 6-10.
PAN Zonghui, LIU Zhi, LI Fufeng, HE Qiong. Influence of Factors on Motion Artifacts in Strain Estimation with Spatial Angular Compounding. China Medical Devices, 2019, 34(5): 6-10.