Showing papers by "Johan M. Thijssen published in 1990"
TL;DR: Methods to derive the phase-derivative (PD) signal from the complex envelope and the preenvelope of the echo signal are described and first and second order characteristics of the PD images are calculated for the conditions employed in simulations and experiments and are quantitatively compared to the values obtained from these.
9 citations
01 Jan 1990
TL;DR: The animal model employed was an amelanotic melanoma implanted in the anterior chamber of Dutch rabbit to investigate the potentials of acoustospectrographic analysis for the characterization of biological tissues in general and of intraocular tumours in particular.
Abstract: This study has been performed to investigate the potentials of acoustospectrographic analysis for the characterization of biological tissues in general and of intraocular tumours in particular. The animal model employed was an amelanotic melanoma (Greene) implanted in the anterior chamber of Dutch rabbit. The eyes containing a tumour were scanned in vivo and after enucleation for a second time in vitro. The scanning was performed with a commercial B-scanner that was interfaced to a data-acquisition and processing system. The attenuation and backscattering parameters were estimated from the spectra calculated from the radiofrequency echograms.