Microdevice's susceptibility difference based MRI positioning system, a preliminary investigation

A positioning technique for an endovascular microdevice propelled by magnetic force inside a magnetic resonance imaging (MRI) system is being developed. Positioning options are presented and a magnetic positioning technique is described in more details. Since a magnetic positioning system is deeply dependent on the quality of the measurement modality, we describe the main magnetic field measurement techniques that can be used inside an MRI. Finally, we propose a magnetic positioning system using MRI phase images to measure the magnetic distortion induced by the ferromagnetic body. Positioning results on a 1010/1020 carbon steel, 1.5875 mm diameter sphere with gradient echo phase images are presented.