Sound fields for coded excitations in water and tissue: experimental approach.

Area of Science:

• Medical Imaging
• Acoustics
• Biomedical Engineering

Background:

• Coded ultrasonography is explored for enhanced penetration depth and signal-to-noise ratio (SNR).
• Limited data exists on the spatial behavior of pressure fields from coded burst transmissions in biological tissues.

Purpose of the Study:

• To investigate and report the spatial behavior of the pressure field generated by coded burst transmissions in various media.
• To compare the field structure of different coded excitations with conventional short pulse excitation.

Main Methods:

• Experiments were conducted in water, degassed beef liver, and pork tissue.
• Four excitation signals were used: 2 and 16-period sine bursts, 13-bit Barker code, and 16-bit Golay complementary codes.
• Measured pressure field distributions were analyzed and compared to short pulse excitation results.

Main Results:

• Detailed spatial pressure field distributions were mapped for different coded transmissions in tissue-mimicking materials.
• Comparison revealed distinct field characteristics for coded bursts versus short pulses.
• The study provides the first reported data on the spatial behavior of coded ultrasound pressure fields in tissue.

Conclusions:

• Coded ultrasound burst transmissions exhibit unique spatial pressure field characteristics in biological tissues.
• Understanding these field structures is crucial for optimizing coded ultrasound imaging techniques.
• This research lays the groundwork for further development of advanced ultrasound imaging modalities.