A Targeted Molecular Localization Imaging Method Applied to Tumor Microvasculature.

Area of Science:

• Biomedical Imaging
• Molecular Imaging
• Vascular Biology

Background:

• Ultrasound contrast agents (microbubbles) are used in molecular imaging and ultrasound localization microscopy.
• Current methods image vasculature and molecular markers separately, limiting simultaneous analysis.
• There is a need for integrated imaging to provide both anatomical and biological disease indicators.

Purpose of the Study:

• To introduce a novel targeted molecular localization (TML) imaging approach.
• To enable simultaneous co-localization of super-resolved vasculature and molecular imaging signatures.
• To provide multiscale disease evaluation by combining anatomic and biological information.

Main Methods:

• Developed a targeted molecular localization (TML) imaging technique using a single imaging sequence and reconstruction.
• Validated the TML technique in a murine hindlimb tumor model with control, tumor, and post-treatment groups.
• Calculated quantitative metrics including vascular index (VI), molecular index (MITML), and a novel ratio of molecular index to vessel surface.

Main Results:

• TML imaging resolved microvasculature down to 28.8 μm.
• A significant decrease in MITML was observed in treated tumors and control legs compared to untreated tumors.
• The ratio of molecular index to vessel surface showed statistically significant differences between all tested groups, differentiating tissue states.

Conclusions:

• The targeted molecular localization (TML) method is technically feasible.
• TML imaging demonstrates pre-clinical feasibility for distinguishing normal from diseased tissue.
• This technique offers simultaneous anatomic and biological insights for disease assessment.