Ultrasound contrast imaging: current and new potential methods

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Acoustics

Background:

• Conventional ultrasound imaging (fundamental imaging) was insufficient for detecting ultrasound contrast agents in tissue for a decade.
• Limitations in sensitivity hindered effective visualization of contrast agents with traditional methods.

Purpose of the Study:

• To review the evolution of ultrasound contrast imaging techniques.
• To highlight the importance of contrast agent properties for improved detection.
• To discuss current and emerging modalities for enhanced ultrasound contrast imaging.

Main Methods:

• Review of existing ultrasound contrast imaging modalities, including fundamental, second harmonic, harmonic power Doppler, and pulse inversion.
• Discussion of emerging techniques like release burst and subharmonic imaging.
• Analysis of contrast agent properties such as nonlinear and transient scattering.

Main Results:

• Fundamental imaging lacks the sensitivity required for effective contrast agent detection in tissue.
• Advanced techniques utilizing nonlinear and transient scattering properties demonstrate superior sensitivity.
• Second harmonic imaging, especially with power Doppler, is highly sensitive but not optimal for perfusion.
• New modalities are continuously emerging to improve contrast imaging.

Conclusions:

• A comprehensive understanding of ultrasound-contrast agent interactions is crucial for advancing imaging technology.
• Developing new imaging techniques based on specific agent properties will enhance diagnostic capabilities.
• Continued research into novel modalities promises more sensitive and specific ultrasound contrast imaging.