New Magnetic Resonance Imaging Method


Research team led by RWTH Professor Stephan Appelt discovers RASER MRI


Professor Stephan Appelt, Chair of Macromolecular Chemistry at RWTH Aachen University and Forschungszentrum Jülich, has discovered a fundamentally new method for RASER-MRI (Radiofrequency Amplification by Stimulated Emission of Radiation). He has achieved this with the assistance of colleagues from RWTH, the Karlsruhe Institute of Technology, and the universities of Raleigh, Wayne State, and Harvard. The international research team has now published this new approach in magnetic resonance imaging in the journal Science Advances.

Magnetic resonance imaging or tomography (MRI) is one of the most important examination methods in medical diagnostics and materials science. In previous MRI techniques, you excite nuclear spins (protons) in the tissue or samples with an external radio frequency and then measure the emitted radio signal in the presence of a magnetic field gradient.

RASER MRI, on the other hand, does not use an external radio frequency, as the RASER MRI image is created by itself, so to speak, through self-organization. Not having to use radiofrequency radiation means less radiation exposure for the patient's tissue and at the same time less hardware is required for the MRI scanner. Instead, the necessary negative polarization of the protons is achieved by means of hyperpolarization technology, which has become increasingly efficient and cost-effective in recent years.

RASER-MRI is also based on a cooperative interaction between the individual image points (voxels). The image contrast is therefore no longer a local but a global property. Each voxel responds, so to speak, to the overall state of all other voxels. Compared to previous MRI, this new contrast mechanism is more sensitive to small local changes. This could be significant for medical diagnostics, such as MRI imaging of tumors. Overall, there is much to suggest that the physics and technology of RASER MRI will enable new applications in the field of quantum sensing or quantum information technology, in addition to medical diagnostics.