Cyril Tous1,2, Ning Li1,2, Ivan P Dimov1, Samuel Kadoury3, An Tang1,2, Urs O Häfeli4, Zeynab Nosrati4, Katayoun Saatchi4, Gerald Moran5, Marcus J Couch5, Sylvain Martel3, Simon Lessard2,6, Gilles Soulez7,8. 1. Centre de recherche du Centre hospitalier de l, Université de Montréal (CRCHUM), 900 Rue Saint-Denis, Montreal, QC, H2X 0A9, Canada. 2. Université de Montréal, 2900 Boulevard Édouard-Montpetit, Montreal, QC, H3T 1J4, Canada. 3. Polytechnique Montréal, 2500 Chemin de Polytechnique, 28, Montreal, QC, H3T 1J4, Canada. 4. University of British Columbia, 2405 Westbrook Mall, Vancouver, BC, V6T 1Z3, Canada. 5. Siemens Healthineers, Erlangen, Canada. 6. École de Technologie Supérieur, 1100 Rue Notre-Dame O, Montreal, QC, H3C 1K3, Canada. 7. Centre de recherche du Centre hospitalier de l, Université de Montréal (CRCHUM), 900 Rue Saint-Denis, Montreal, QC, H2X 0A9, Canada. gilles.soulez.med@ssss.gouv.qc.ca. 8. Université de Montréal, 2900 Boulevard Édouard-Montpetit, Montreal, QC, H3T 1J4, Canada. gilles.soulez.med@ssss.gouv.qc.ca.
Abstract
INTRODUCTION: Magnetic resonance navigation (MRN) uses MRI gradients to steer magnetic drug-eluting beads (MDEBs) across vascular bifurcations. We aim to experimentally verify our theoretical forces balance model (gravitational, thrust, friction, buoyant and gradient steering forces) to improve the MRN targeted success rate. METHOD: A single-bifurcation phantom (3 mm inner diameter) made of poly-vinyl alcohol was connected to a cardiac pump at 0.8 mL/s, 60 beats/minutes with a glycerol solution to reproduce the viscosity of blood. MDEB aggregates (25 ± 6 particles, 200 [Formula: see text]) were released into the main branch through a 5F catheter. The phantom was tilted horizontally from - 10° to +25° to evaluate the MRN performance. RESULTS: The gravitational force was equivalent to 71.85 mT/m in a 3T MRI. The gradient duration and amplitude had a power relationship (amplitude=78.717 [Formula: see text]). It was possible, in 15° elevated vascular branches, to steer 87% of injected aggregates if two MRI gradients are simultaneously activated ([Formula: see text] = +26.5 mT/m, [Formula: see text]= +18 mT/m for 57% duty cycle), the flow velocity was minimized to 8 cm/s and a residual pulsatile flow to minimize the force of friction. CONCLUSION: Our experimental model can determine the maximum elevation angle MRN can perform in a single-bifurcation phantom simulating in vivo conditions.
INTRODUCTION: Magnetic resonance navigation (MRN) uses MRI gradients to steer magnetic drug-eluting beads (MDEBs) across vascular bifurcations. We aim to experimentally verify our theoretical forces balance model (gravitational, thrust, friction, buoyant and gradient steering forces) to improve the MRN targeted success rate. METHOD: A single-bifurcation phantom (3 mm inner diameter) made of poly-vinyl alcohol was connected to a cardiac pump at 0.8 mL/s, 60 beats/minutes with a glycerol solution to reproduce the viscosity of blood. MDEB aggregates (25 ± 6 particles, 200 [Formula: see text]) were released into the main branch through a 5F catheter. The phantom was tilted horizontally from - 10° to +25° to evaluate the MRN performance. RESULTS: The gravitational force was equivalent to 71.85 mT/m in a 3T MRI. The gradient duration and amplitude had a power relationship (amplitude=78.717 [Formula: see text]). It was possible, in 15° elevated vascular branches, to steer 87% of injected aggregates if two MRI gradients are simultaneously activated ([Formula: see text] = +26.5 mT/m, [Formula: see text]= +18 mT/m for 57% duty cycle), the flow velocity was minimized to 8 cm/s and a residual pulsatile flow to minimize the force of friction. CONCLUSION: Our experimental model can determine the maximum elevation angle MRN can perform in a single-bifurcation phantom simulating in vivo conditions.