Righetti Raffaella, Srinivasan Seshadri, Ophir Jonathan
The University of Texas Medical School, Department of Radiology, Ultrasonics Laboratory, Houston, TX 77030, USA.
Ultrasound Med Biol. 2003 May;29(5):695-704. doi: 10.1016/s0301-5629(03)00028-0.
The factors that control the lateral resolution in elastography were investigated using a simulation study. The lateral resolution was estimated from the simulated axial strain elastograms as the smallest measurable distance between two equally stiff lesions embedded in a homogeneously softer background. The lesions were symmetrically positioned lateral to the center of the target, at the focus of the transducer. Ultrasound (US) systems with different transducer frequencies, bandwidths and f-numbers were simulated. The effects of the ultrasonic parameters, the lateral spacing between adjacent echo signals, the cross-correlation window length, the lesion/background elastic contrast and the lateral motion of scatterers on the estimated lateral resolution were investigated. The results show that the lateral resolution in elastography is proportional to the beam width of the US system used to acquire the data, and is on the same order as the sonographic lateral resolution.
通过模拟研究对弹性成像中控制横向分辨率的因素进行了调查。横向分辨率是从模拟的轴向应变弹性图中估计出来的，即嵌入均匀较软背景中的两个同等硬度病变之间的最小可测量距离。病变对称地位于目标中心的横向，在换能器的焦点处。模拟了具有不同换能器频率、带宽和f数的超声（US）系统。研究了超声参数、相邻回波信号之间的横向间距、互相关窗口长度、病变/背景弹性对比度以及散射体的横向运动对估计横向分辨率的影响。结果表明，弹性成像中的横向分辨率与用于采集数据的超声系统的波束宽度成正比，并且与超声横向分辨率处于同一量级。
