Synchronously Amplified Photoacoustic Image Recovery (SAPhIRe).

Area of Science:

• Biomedical Optics
• Molecular Imaging
• Nanotechnology

Background:

• Photoacoustic imaging (PAI) is challenged by endogenous absorbers, limiting contrast.
• Exogenous contrast agents are crucial for molecular and cellular PAI.
• Existing methods struggle to differentiate signals from background noise.

Purpose of the Study:

• To develop an ultra-sensitive PAI technique by rejecting endogenous background signals.
• To improve signal contrast in PAI using optically modulatable nanoparticles.
• To demonstrate a novel method for background-free photoacoustic signal recovery.

Main Methods:

• Utilized optically modulatable nanoparticles with time-delayed pump-probe pulsed laser illumination.
• Implemented real-time image processing to recover modulatable photoacoustic (mPA) signals.
• Tested the technique in tissue-mimicking phantoms and ex-vivo tissues.

Main Results:

• Achieved background-free photoacoustic signal recovery.
• Demonstrated drastically improved signal contrast compared to conventional PAI.
• Showcased ultra-sensitive imaging by rejecting endogenous background.
• Validated the method in phantoms and ex-vivo tissue samples.

Conclusions:

• Synchronously Amplified Photoacoustic Image Recovery (SAPhIRe) offers a promising solution for ultra-sensitive PAI.
• The technique effectively eliminates endogenous background noise.
• SAPhIRe enhances contrast and sensitivity for improved diagnostic and therapeutic applications.
• The inherent multimodality (fluorescence and mPA) broadens its clinical potential.