An acoustic microscope using water as the coupling medium has been operated at frequencies up to 4.4 GHz. The signal-to-noise ratio is sufficient for imaging and the acoustic images demonstrate that the resolution is better than 2000 Å when the instrument is operated in the nonlinear regime.
No takes yet. Share an insight, caveat, or question.
Hadimioglu et al. (1983) studied this question.
Synapse has enriched 2 closely related papers on similar clinical questions. Consider them for comparative context: