PDF(Pubmed)
Abstract：
Contrast-enhanced ultrasound (CEUS) acquisitions of focal liver lesions are affected by motion, which has an impact on contrast signal quantification. We therefore developed and tested, in a large patient cohort, a motion compensation algorithm called the Iterative Local Search Algorithm (ILSA), which can correct for both periodic and non-periodic in-plane motion and can reject frames with out-of-plane motion. CEUS cines of 183 focal liver lesions in 155 patients from three hospitals were used to develop and test ILSA. Performance was evaluated through quantitative metrics, including the root mean square error and R2 in fitting time-intensity curves and standard deviation value of B-mode intensities, computed across cine frames), and qualitative evaluation, including B-mode mean intensity projection images and parametric perfusion imaging. The median root mean square error significantly decreased from 0.032 to 0.024 (p < 0.001). Median R2 significantly increased from 0.88 to 0.93 (p < 0.001). The median standard deviation value of B-mode intensities significantly decreased from 6.2 to 5.0 (p < 0.001). B-Mode mean intensity projection images revealed improved spatial resolution. Parametric perfusion imaging also exhibited improved spatial detail and better differentiation between lesion and background liver parenchyma. ILSA can compensate for all types of motion encountered during liver CEUS, potentially improving contrast signal quantification of focal liver lesions.
摘要：
局灶性肝脏病变的超声造影（CEUS）采集受运动影响，这对对比信号定量有影响。因此，我们开发和测试，在一个庞大的患者队列中，一种称为迭代局部搜索算法(ILSA)的运动补偿算法，它可以校正周期性和非周期性的平面内运动，并且可以拒绝具有平面外运动的帧。来自三家医院的155名患者的183例局灶性肝脏病变的CEUS切片用于开发和测试ILSA。通过定量指标评估绩效，包括拟合时间-强度曲线的均方根误差和R2以及B模式强度的标准偏差值，跨电影帧计算)，和定性评估，包括B型平均强度投影图像和参数灌注成像。中位数均方根误差从0.032显著下降到0.024(p<0.001)。中值R2从0.88显著增加到0.93(p<0.001)。B模式强度的中值标准偏差值从6.2显著降低到5.0(p<0.001)。B模式平均强度投影图像显示出改进的空间分辨率。参数灌注成像还显示出改善的空间细节以及病变和背景肝实质之间的更好区分。ILSA可以补偿肝脏CEUS期间遇到的所有类型的运动，可能改善肝脏局灶性病变的对比信号定量。
