Improved in-stent lumen visualization using intravascular MRI and a balanced steady-state free-precession sequence

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Interventional Cardiology

Background:

• Vascular stents can cause radiofrequency (RF) shielding during magnetic resonance (MR) imaging, hindering visualization of the in-stent lumen.
• Improving MR imaging of stented vessels is crucial for monitoring stent performance and detecting in-stent restenosis.

Purpose of the Study:

• To evaluate an intravascular loopless antenna for reducing RF shielding caused by vascular stents.
• To enhance the visualization and quantification of the in-stent lumen and detect in-stent restenosis.

Main Methods:

• Utilized a balanced steady-state free-precession (bSSFP) sequence in a vascular phantom.
• Compared signal-to-noise ratio (SNR) inside stented and non-stented vessels using an intravascular loopless antenna and surface coils.
• Performed in vitro experiments to visualize and quantify in-stent restenosis.

Main Results:

• The loopless antenna effectively eliminated RF shielding from the stent during signal reception.
• Optimized bSSFP parameters achieved comparable blood SNR inside and outside the stent.
• Demonstrated successful in vitro visualization and quantification of in-stent restenosis using the intravascular antenna.

Conclusions:

• Intravascular antennas significantly facilitate MR imaging within vascular stents.
• This technology holds promise for MR-guided vascular interventions, including stent deployment monitoring and in-stent restenosis assessment.