The random phase transducer: a new technique for incoherent processing-experimental results.

Area of Science:

• Medical imaging
• Acoustics
• Biomedical engineering

Background:

• Ultrasonic speckle is inherent to biological tissues, acting as noise in echo detection and power spectra.
• This noise can degrade the quality and accuracy of ultrasound diagnostic information.

Purpose of the Study:

• To introduce and evaluate a novel technique using a random phase screen (RPS) to control spatial coherence in ultrasonic beams.
• To assess the effectiveness of the RPS method in reducing speckle noise and improving signal-to-noise ratio (SNR).

Main Methods:

• A random phase screen (RPS) was designed, featuring a rough surface inducing random phase shifts (0 to 2pi).
• Measurements were conducted using unfocused and focused transducers in broadband pulse-echo mode with the RPS.
• The system's directivity pattern and ability to generate uncorrelated speckle patterns were experimentally evaluated.

Main Results:

• The RPS effectively controlled the spatial coherence of the ultrasonic beam.
• Experimental results demonstrated the system's capability to obtain uncorrelated speckle patterns.
• The RPS technique showed significant improvements in signal-to-noise ratio (SNR), aligning with theoretical predictions.

Conclusions:

• The random phase screen (RPS) is a viable method for controlling ultrasonic speckle noise.
• This technique offers a promising approach for enhancing image quality and diagnostic accuracy in ultrasound imaging.
• The experimental findings validate the theoretical basis for using RPS in ultrasound applications.