One-transmission harmonic imaging with high spatial resolutions using probe consisting of two piezoelectric layer...

Area of Science:

• Ultrasound technology
• Medical imaging
• Materials science

Background:

• Pulse inversion (PI) harmonic imaging offers superior contrast and spatial resolution over fundamental imaging.
• A key limitation of PI harmonic imaging is the reduced frame rate due to the requirement of two transmissions.

Purpose of the Study:

• To develop a novel ultrasonic array probe capable of extracting second harmonic components with a single transmission.
• To overcome the frame rate reduction inherent in conventional pulse inversion harmonic imaging.

Main Methods:

• Developed an ultrasonic array probe with piezoelectric elements featuring two polarization-inverted layers.
• Predicted and measured the probe's electric impedance and phase characteristics using piezoelectric and wave equations.
• Measured acoustic pressures and performed imaging of targets in water and phantoms.

Main Results:

• The developed probe demonstrated significantly improved spatial resolution, particularly in the axial direction, compared to conventional second harmonic imaging (HI) with a band pass filter.
• The spatial resolution achieved was comparable to conventional PI imaging, despite requiring only one transmission.

Conclusions:

• A new probe utilizing two polarization-inverted piezoelectric layers was successfully developed, enabling single-transmission harmonic imaging.
• The developed probe offers a promising solution for enhancing imaging frame rates without substantial compromise in spatial resolution compared to PI imaging.