EXPERIMENTAL STUDIES ON AN EFFICIENT CATHETER ARRAY IMAGING-SYSTEM

A new synthetic aperture system for intraluminal imaging has been test ed using a 32 element, 20 MHz circular array wrapped around the surfac e of a catheter appropriate for coronary artery applications. This sys tem is based on an optimal reconstruction method that has been extende d to reduce grating lobes using a slight modification to classic synth etic aperture data acquisition. Optimal reconstruction filters have be en derived for two different operating modes based on this new data ac quisition strategy. Imaging results on a wire target phantom show that spatial resolution is a simple linear function of depth, reaching a m inimum 6 dB beam width of approximately 2.2 wavelengths. Sidelobe leve ls are inherently high for this system because of the small number of firings used to synthesize an aperture. Optimal reconstruction filters , however, can reduce these sidelobes to at least -20 dB in all cases. Finally, images of an excised segment of porcine femoral artery demon strate the overall performance of the system as an intraluminal imager . (C) 1995 Academic Press, Inc.