Optical and Photoacoustic Imaging.

Area of Science:

• Biomedical Optics
• Preclinical Imaging
• Optical Spectroscopy

Background:

• Optical imaging offers versatile, sensitive, real-time monitoring for preclinical tumor studies.
• Key techniques include fluorescence, bioluminescence, and photoacoustic imaging, each with unique advantages and limitations.
• Challenges include limited tissue penetration due to light scattering and absorption.

Purpose of the Study:

• To review the benefits and limitations of major in vivo optical imaging modalities for preclinical tumor evaluation.
• To highlight advancements extending the utility of these techniques.
• To discuss their suitability for clinical translation.

Main Methods:

• Review of fluorescence imaging, including near-infrared fluorescent (NIRF) probes and advanced strategies.
• Analysis of bioluminescence imaging (BLI) and its reliance on genetic modification.
• Examination of photoacoustic imaging (PAI) principles, contrast mechanisms, and depth penetration.
• Consideration of 3D imaging and deep learning applications.

Main Results:

• Fluorescence imaging is simple, enhanced by NIRF probes and multimodal strategies for surgical applications.
• Bioluminescence imaging offers high sensitivity but requires genetic modification, limiting human use.
• Photoacoustic imaging provides better depth penetration, utilizes endogenous contrast for vascular and tumor imaging, and is well-suited for clinical translation due to safety.
• All techniques benefit from 3D imaging and deep learning.

Conclusions:

• Optical imaging modalities are indispensable tools in preclinical tumor research.
• Photoacoustic imaging shows significant promise for clinical translation due to its safety and penetration.
• Ongoing developments in 3D imaging and AI are crucial for advancing optical techniques.