Axial resolution in elastography.

The limits and trade-offs of the axial resolution in elastography were investigated using a controlled simulation study. The axial resolution in elastography was estimated as the distance between the full widths at half-maximum of the strain profiles of two equally stiff lesions embedded in a softer homogeneous background. The results show that the upper bound of the axial resolution in elastography is controlled by the physical wave parameters of the ultrasound (US) system used to acquire the data (transducer center frequency and band- width). However, an inappropriate choice of the parameters used to process the US data (cross-correlation window length and shift between consecutive windows) may compromise the best resolution attainable. The measured elastographic axial resolution was found to be on the order of the ultrasonic wavelength.