Development of an intravascular heating source using an MR imaging guidewire

Area of Science:

• Biomedical Engineering
• Interventional Cardiology
• Molecular Medicine

Background:

• Gene transfection is crucial for treating vascular diseases.
• Current methods for vascular gene delivery face challenges in efficiency and targeting.
• Endovascular thermal enhancement offers a promising approach to improve transfection rates.

Purpose of the Study:

• To develop and evaluate a novel endovascular heating source using a magnetic resonance imaging guidewire (MRIG).
• To deliver controlled microwave energy for thermal enhancement of vascular gene transfection.
• To assess the safety and efficacy of MRIG-based localized heating in a preclinical model.

Main Methods:

• A 0.032-inch MRIG was connected to a 2.45-GHz microwave generator.
• Microwave power loss and distribution were calculated and simulated.
• Temperature increase versus input power was measured.
• Thermal effects on rabbit aortas were evaluated, with simultaneous MR imaging.

Main Results:

• Power loss along the MRIG was calculated at 3.9 dB.
• Simulations showed a cylindrically symmetric power distribution, suitable for vessel geometry.
• Localized heating of the vessel wall to 41°C was achieved without thermal damage.
• High-resolution MR images of the aortic wall were generated simultaneously.

Conclusions:

• The MRIG functions as a multifunctional device for intravascular imaging and interventions.
• It serves as a potential intravascular heating source for thermal enhancement of gene transfection.
• This technology demonstrates feasibility for localized, controlled endovascular heating.