Cross Amplitude Modulation and Compound Amplitude Modulation for Nonlinear Contrast-Enhanced Ultrasound Imaging of...

Area of Science:

• Ultrasound Imaging
• Biomedical Engineering
• Nanotechnology

Background:

• Nonlinear contrast-enhanced ultrasound (CEUS) imaging utilizes nanobubbles (NBs) for enhanced microvascular visualization and molecular imaging.
• Amplitude Modulation (AM) techniques offer potential improvements in NB-mediated CEUS.

Purpose of the Study:

• To explore and compare two AM techniques: cross amplitude modulation (xAM) and compound amplitude modulation (cAM).
• To evaluate their effectiveness in enhancing NB-mediated CEUS imaging capabilities.

Main Methods:

• Testing xAM and cAM on the Vevo F2 ultrasound system with Vevo Advanced Data Acquisition (VADA) mode.
• xAM employed a three-event pulse sequence with cross-propagating plane-wave beams to isolate NB signals.
• cAM combined plane-wave compounding with amplitude modulation for high frame rates.

Main Results:

• xAM significantly improved contrast-to-noise ratio (CNR) and contrast-to-tissue ratio (CTR) by over 10 times compared to B-mode.
• cAM achieved a frame rate of 706 Hz, over 100 times faster than xAM, but with 50% lower CNR and CTR.
• NBs at 10^9 NBs/mL were used in tissue-mimicking vessel phantoms.

Conclusions:

• xAM enhances imaging clarity and contrast in NB-mediated CEUS.
• cAM provides high frame rates crucial for tracking vascular flow dynamics.
• These techniques offer a versatile imaging framework for preclinical and clinical applications.