Structure function for high-concentration biophantoms of polydisperse scatterer sizes

Area of Science:

• Biomedical Ultrasound
• Acoustic Metrology
• Tissue Optics

Background:

• Ultrasonic backscattering coefficient (BSC) is vital for tissue characterization, typically assuming sparse scatterers.
• Dense scattering media in many tissues pose challenges for current models.
• Scatterer correlation and polydispersity are often overlooked in ultrasonic models.

Purpose of the Study:

• To develop and validate structure function models for dense media ultrasonic scattering.
• To investigate the impact of scatterer polydispersity on structure functions.
• To improve ultrasonic tissue characterization accuracy in dense media.

Main Methods:

• Theoretical development of structure function models incorporating polydisperse scatterers.
• Experimental evaluation using cell pellet biophantoms with known cell concentrations.
• Estimation of BSCs using single-element transducers (11-105 MHz).
• Comparison of experimental and model-predicted structure functions.

Main Results:

• Models based on polydisperse scatterers accurately predicted experimental structure functions.
• Fitting models yielded cell radius estimates consistent with microscopy.
• Demonstrated the significant role of scatterer position correlation and polydispersity.

Conclusions:

• Structure functions effectively model dense media scattering by considering scatterer correlation.
• Scatterer polydispersity significantly influences structure functions in ultrasonic scattering.
• This approach enhances the accuracy of ultrasonic scattering models for tissue characterization.