High-Speed, Pixel-Super-resolved Compressive Second Near-Infrared Fluorescence In Vivo Imaging

Area of Science:

• Biomedical Optics
• Medical Imaging
• Fluorescence Imaging

Background:

• Conventional second near-infrared (NIR-II) fluorescence imaging struggles with simultaneous high signal-to-noise ratio and motion-artifact-free capture of rapid physiological dynamics.
• Limitations in current imaging techniques hinder the real-time visualization of fast biological processes in deep tissues.

Purpose of the Study:

• To introduce NIR-II compressive fluorescence imaging (COFI), a novel technique for high-speed, pixel-super-resolved imaging.
• To overcome the limitations of conventional NIR-II imaging in capturing rapid physiological dynamics with high fidelity.

Main Methods:

• Developed NIR-II COFI using a high-speed spatial light modulator and a low-frame-rate NIR-II camera to encode dynamics into single frames.
• Employed a hybrid reconstruction algorithm combining a denoising convolutional neural network and a super-resolution generative adversarial network for video restoration.
• Utilized bright 1,525-nm nanoparticle probes for imaging.

Main Results:

• Achieved a high-speed imaging rate of 3.3 kiloframes per second with a space-bandwidth-time product of 4.22 × 10⁸ pixels/s.
• Demonstrated a 36% improvement in signal-to-noise ratio compared to conventional short-exposure imaging.
• Successfully visualized multicomponent phosphorescence lifetime, high-speed motion tracking, and real-time murine intestinal peristalsis in vivo.

Conclusions:

• NIR-II COFI enables high-fidelity, high-speed in vivo imaging of fast biological processes without compromising intrinsic sensitivity.
• The technique facilitates deep-tissue imaging and overcomes motion artifacts, offering significant advancements over conventional methods.
• This work paves the way for enhanced understanding of dynamic biological processes in real-time.