3T MRI scanner magnetic gradient mapping using a 3D Hall probe

The unique relationship between Magnetic Resonance Imaging (MRI) scanner bore space coordinates and magnetic field gradients used in MRI allows building a location system based on the measurement of these gradients. For the first time, these magnetic gradients are accurately measured thanks to a miniature 3D Hall probe integrated in a low cost, low voltage 0.35μm CMOS process. The magnetic gradient 3D map of a 3T MRI scanner has been measured and experimental results show that a sub-millimeter location of the probe is possible. It opens the way for the development of MRI compatible magnetic tracking systems integrable in a surgical tool.