Artifactual echoes in B-mode images due to multiple scattering

Area of Science:

• Medical Imaging
• Ultrasound Physics
• Biomedical Engineering

Background:

• Artifactual echoes in B-mode ultrasound can obscure true anechoic regions.
• Multiple scattering from echogenic regions is a source of these artifactual echoes.
• Understanding multiple scatter is crucial for accurate image interpretation.

Purpose of the Study:

• To quantify the contribution of multiple scatter to artifactual echoes in ultrasound B-mode imaging.
• To assess the impact of multiple scatter in different phantom materials and biological tissues.
• To evaluate the significance of multiple scatter artifacts in liver and breast imaging.

Main Methods:

• Utilized plane boundary phantoms with varying scattering properties and anechoic regions.
• Employed multiple focused and conventional ultrasound transducers in pulse echo mode.
• Measured echo amplitudes from artifactual signals in phantom and excised human tissue samples.

Main Results:

• Multiple scatter echoes ranged from 3-9% of the average signal in the strongest scattering phantom with focused transducers.
• Multiple scatter was less than 5% for a conventional transducer.
• Artifactual echoes were estimated to be negligible in liver but significant in breast tissue.

Conclusions:

• Multiple scatter is a quantifiable source of artifactual echoes in ultrasound B-mode imaging.
• The level of artifactual echoes due to multiple scatter varies with transducer type and tissue properties.
• Findings suggest potential limitations for artifactual echo interpretation in breast ultrasound, necessitating further investigation.