Magnetic Resonance Navigation for Targeted Embolization in a Two-Level Bifurcation Phantom

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Interventional Radiology

Background:

• Hepatocellular carcinoma (HCC) treatment often involves targeted therapies like chemoembolization.
• Accurate delivery of therapeutic agents to tumor sites is crucial for effective endovascular treatment.
• Magnetic drug-eluting beads (MDEBs) offer a promising approach for targeted drug delivery, but precise navigation remains a challenge.

Purpose of the Study:

• To validate the efficacy of a proposed magnetic resonance navigation (MRN) sequence for guiding MDEB aggregates.
• To assess MRN's performance in a two-bifurcation phantom relevant to hepatocellular carcinoma endovascular treatment.
• To evaluate the impact of MRN on MDEB distribution within complex vascular structures.

Main Methods:

• Developed a theoretical model to determine optimal MDEB aggregate size (200 μm).
• Utilized a specialized particle injector to deliver MDEB aggregates into a two-bifurcation phantom.
• Implemented an MRN sequence with interleaved tracking and steering, triggered automatically by MRI, to guide aggregates.

Main Results:

• MRN significantly improved MDEB distribution ratios in all target branches, with some reaching 100% compared to baseline (e.g., left-right branch).
• In a perpendicular orientation, MRN increased MDEB delivery to a previously untreated branch (right-left) from 0% to 80%.
• The MRN protocol demonstrated a high success rate, exceeding 92% at the first bifurcation across experiments.

Conclusions:

• The proposed MRN sequence effectively guides MDEB aggregates within a complex vascular phantom.
• MRN significantly enhances the precision of targeted delivery for potential endovascular HCC therapies.
• This validated MRN system shows promise for improving the outcomes of MDEB-based treatments.