High-speed simultaneous multiscale photoacoustic microscopy.

Area of Science:

• Biomedical Imaging
• Optical Engineering
• Medical Technology

Background:

• Photoacoustic microscopy (PAM) offers high-resolution in vivo imaging beyond optical diffusion limits.
• PAM is categorized into optical resolution PAM (OR-PAM) and acoustic resolution PAM (AR-PAM) based on resolution and depth.
• Microelectromechanical systems (MEMS) scanners enhance OR-PAM speed but are limited by shallow penetration depth.

Purpose of the Study:

• To develop and demonstrate a high-speed, wide-area scanning integrated OR-AR-PAM system.
• To leverage a high-speed MEMS scanner for both OR-PAM and AR-PAM modalities.
• To overcome the penetration depth limitations of OR-PAM for broader clinical applications.

Main Methods:

• Integration of a high-speed MEMS scanner with raster mechanical scanning.
• Development of a combined OR-PAM and AR-PAM system.
• In vivo imaging experiments using specific wavelengths for each modality.

Main Results:

• OR-PAM achieved a lateral resolution of 5 μm and a penetration depth of approximately 0.9 mm in vivo at 586 nm.
• AR-PAM achieved a lateral resolution of 84 μm and a penetration depth of approximately 2 mm in vivo at 532 nm.
• The integrated system demonstrated effective wide-area scanning capabilities.

Conclusions:

• A high-speed MEMS scanner can be effectively utilized for both OR-PAM and AR-PAM.
• The integrated OR-AR-PAM system expands the capabilities of PAM for in vivo imaging.
• This technology holds promise for advanced biomedical imaging and potential handheld devices.