Optical Magnetometry for MRI

The work is a collaboration between Quantop (Niels Bohr Institute) and DRCMR (Hvidovre hospital).

We are developing a fiber coupled optical magnetometer for use in magnetic resonance imaging (MRI). The optical magnetometer is based on saturated absorption spectroscopy in a cesium vapor. By tracking magnetic field changes during an MRI scan, k-space trajectories can be corrected, leading to improved image quality. By using a fiber coupled optical magnetometer, we can measure the field, without introducing electronic equipment, metallic parts, or even wires near the MR scanner. That is, without disturbing the MR scanners operation, or introducing safety hazards.

The optical magnetometer is being developed in Quantop and is being tested in the 7 T scanner DRCMR.

Picture of fiber coupled probes

By now 4 probes and a reference have been 3D printed. 3 x 17 m of fibers allow the electronics and the lasers to be placed far from the MRI scanner. The probes are 90 x 33 x 10 mm^3 allowing them to easily be placed in the MR scanner, e.g. inside a head coil for brain scans.

Current efforts are now on demonstrating a proof of principle operation of these four probes, by optimizing and finishing the electronics and laser systems.

When sufficient sensitivity is reached, we will proceed to demonstrating that this can actually be useful in medical diagnostics, by improving image quality. This would equip radiographers with a more powerful tool for producing sharp images of the human body, allowing for better diagnostics of a wide range of diseases.