A Radio-Nano-Platform for T1/T2 Dual-Mode PET-MR Imaging

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Radiochemistry

Background:

• Developing advanced imaging agents is crucial for improving diagnostic accuracy.
• Super-paramagnetic iron oxide nanoparticles (SPIONs) offer potential for multimodal imaging.
• Cheating-free radiolabeling methods are desirable for stable and efficient radiotracer development.

Purpose of the Study:

• To develop a chelate-free radiolabeled nanoparticle platform for simultaneous PET-MR imaging.
• To integrate high spatial resolution of MR with high sensitivity of PET for enhanced diagnostic imaging.
• To utilize SPIONs for dual-mode contrast enhancement and improved image quality.

Main Methods:

• Commercially available SPION (Feraheme®, FH) was labeled with 89Zr using a novel chelate-free heat-induced radiolabeling (HIR) technique.
• Radiochemical yield (RCY) and purity (RCP) were assessed using SEC and radio-TLC.
• Simultaneous PET-MR phantom imaging was performed, and image quality metrics (SNR, FWHM) were analyzed.

Main Results:

• High RCY (92%) and RCP (98%) were achieved with the chelate-free HIR method.
• TEM confirmed 90Zr adsorption onto the SPION surface.
• Co-registered PET-MR images showed significant improvements in spatial resolution (FWHM ≈ 3) and SNR (≈ 8) compared to standalone imaging.

Conclusions:

• Feraheme® is a suitable SPION-based platform for chelate-free radiolabeling of PET tracers for hybrid PET-MR imaging.
• The chelate-free HIR technique is robust and efficient for radiotracer development.
• The developed nano-platform provides an overall image quality gain for simultaneous PET-MR imaging at low dosages.