P1D-1 Pulse Inversion Sequences for Mechanically Scanned Transducers

Mechanically scanned transducers are currently used for tissue harmonic imaging (THI) and nonlinear microbubble imaging at high frequencies. Pulse inversion (PI) techniques are widely used for suppression of the fundamental signal but its effectiveness is reduced by relative tissue/transducer motion. In this study we propose weighted PI-sequences that achieve a significant improvement on the fundamental suppression for acquisitions with a mechanically scanned transducer. Simulations of nonlinear Intravascular Ultrasound (IVUS) beams from a rotating transducer, show an increased fundamental suppression of up to >10 dB as compared to the basic PI technique. Application of the proposed PI-sequence on RF-data from in vivo acquisitions resulted in an extra fundamental suppression of >6 dB. The proposed PI-sequences will help to reduce relative tissue/transducer motion effects and might therefore lead to improved image quality in nonlinear tissue imaging and improved microbubble detection in contrast imaging