Tradeoffs between the axial resolution and the signal-to-noise ratio in elastography

Conventional strain estimation techniques in ultrasound-elastography utilize cross-correlation of the pre- and post-compression signals. The quality of the resulting strain estimates is typically quantified through several factors such as the elastographic SNR (SNR_e), the contrast-to-noise ratio (CNR_e), and the spatial resolution. These quality factors depend on the mechanical, acoustic, and signal processing parameters. We find a trade-off between the achievable SNRe (and CNR_e) and the axial resolution. We also find that the trade-off occurs only with respect to the signal processing parameters, while for the physical parameters (the mechanical and the acoustic parameters) such a tradeoff does not exist. Simulations and experiments were used to corroborate this hypothesis.