Modeling Endovascular MRI Coil Coupling With Transmit RF Excitation

IEEE Trans Biomed Eng. 2017 Jan;64(1):70-77. doi: 10.1109/TBME.2016.2538279. Epub 2016 Mar 4.


Objective: To model inductive coupling of endovascular coils with transmit RF excitation for selecting coils for MRI-guided interventions.

Methods: Independent and computationally efficient FEM models are developed for the endovascular coil, cable, transmit excitation, and imaging domain. Electromagnetic and circuit solvers are coupled to simulate net B1 + fields and induced currents and voltages. Our models are validated using the Bloch-Siegert B1 + mapping sequence for a series-tuned multimode coil, capable of tracking, wireless visualization, and high-resolution endovascular imaging.

Results: Validation shows good agreement at 24-, 28-, and 34-μT background RF excitation within experimental limitations. Quantitative coil performance metrics agree with simulation. A parametric study demonstrates tradeoff in coil performance metrics when varying number of coil turns. Tracking, imaging, and wireless marker multimode coil features and their integration is demonstrated in a pig study.

Conclusion: Developed models for the multimode coil were successfully validated. Modeling for geometric optimization and coil selection serves as a precursor to time consuming and expensive experiments. Specific applications demonstrated include parametric optimization, coil selection for a cardiac intervention, and an animal imaging experiment.

Significance: Our modular, adaptable, and computationally efficient modeling approach enables rapid comparison, selection, and optimization of inductively coupled coils for MRI-guided interventions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Computer-Aided Design
  • Endovascular Procedures / instrumentation*
  • Equipment Design
  • Equipment Failure Analysis
  • Image Enhancement / instrumentation
  • Magnetic Fields
  • Magnetic Resonance Imaging, Interventional / instrumentation*
  • Magnetics / instrumentation*
  • Phantoms, Imaging
  • Scattering, Radiation
  • Transducers*
  • Wireless Technology / instrumentation*