In vivo ultrasound-switchable fluorescence imaging

Area of Science:

• Biomedical Optics
• Medical Imaging
• Nanotechnology

Background:

• Conventional fluorescence imaging struggles with low spatial resolution in deep tissues due to light scattering.
• Ultrasound-switchable fluorescence (USF) imaging offers potential for high-resolution deep tissue visualization.
• Previous in vivo USF imaging was hindered by the lack of stable contrast agents and biodistribution data.

Purpose of the Study:

• To achieve the first successful in vivo ultrasound-switchable fluorescence (USF) imaging in a biological environment.
• To evaluate the stability and biodistribution of a novel near-infrared USF contrast agent.
• To demonstrate the high-resolution imaging capabilities of USF in preclinical models.

Main Methods:

• Development and application of a stable near-infrared contrast agent for USF imaging.
• In vivo USF imaging in mice, including local injections into breast tumors and intravenous injections targeting the spleen.
• Ex vivo USF imaging of mouse spleen.
• Comparison of USF imaging results with computed tomography (CT) for accuracy validation.

Main Results:

• Successful high-resolution in vivo USF imaging was achieved in mice for the first time.
• The USF contrast agent demonstrated excellent stability within the biological environment.
• The primary accumulation site for the contrast agent was identified as the spleen.
• USF imaging accuracy was confirmed through comparison with CT imaging.

Conclusions:

• In vivo USF imaging is feasible and provides high resolution in deep tissues.
• The developed USF contrast agent is stable and exhibits predictable biodistribution, primarily in the spleen.
• USF imaging represents a significant advancement for visualizing biological tissues with enhanced clarity and accuracy.