[MRI Safety Aspects and Artifacts of Atrial Septal Defect and Patent Foramen Ovale Occluders at 1.5 Tesla: a Phantom Study]

Purpose: To investigate the magnetic resonance safety and magnetic resonance artifact intensities of patent foramen ovale and atrial septal occluders in a phantom study.

Materials And Methods: Seven different commercial occluder models (Amplatzer ASD, Angel Wing ASD, Helex Septal Occluder, Cardia PFO-Star Generation I & III, Sideris Buttoned Device, Starflex ASD) were tested in a 1.5 Tesla whole-body MR scanner. Following a deflection test, the non-magnetic devices were imaged using different MRI pulse sequences including conventional spin echo, spoiled gradient echo as well as fast refocused steady-state pulse sequences (trueFISP) commonly used for cardiac MRI. Additionally, device temperatures were measured in the MR scanner during two imaging protocols (trueFISP, HASTE) with an MR-compatible fiber-optical thermometer.

Results: One ferromagnetic device (Sideris Buttoned Device) did not pass the deflection test and was excluded from further experiments. For typical cardiac imaging protocols, the remaining non-ferromagnetic devices showed only minor image artifacts with artifact sizes not exceeding 2 mm next to a strut. Heating was not observed in the devices.

Conclusion: Non-ferromagnetic occluder models used in this study can safely be imaged with typical cardiac MRI protocols at 1.5 Tesla. The device artifact sizes are small enough to allow anatomical and functional MRI even in the immediate vicinity of the occluders.