In vivo magnetic tissue properties mapping



Phase MRI is an advanced imaging technique that utilizes extremely small variations in magnetic fields to measure biological tissues. This method is able to visualize field perturbations caused by the small variations in magnetic properties between different brain regions, which can then be related to various biophysical mechanisms at length scales ranging from molecular to macroscopic. By utilizing this cutting-edge imaging technique, researchers are able to gain a greater understanding of the inner workings of the brain and its associated structures.
Dr. Schweser developed an advanced Phase MRI technique referred to as Quantitative Susceptibility Mapping (QSM) at the Medical Physics Group led by Dr. Jürgen Reichenbach (Friedrich Schiller University Jena ), which enables the quantification of tissue magnetic susceptibility in the brain and other organs. QSM quantifies the tissue magnetic susceptibility via a mathematical inversion of the underlying physics problem. While being increasingly applied in clinical studies, the physical model currently used in QSM neglects field variations that are not directly related to bulk, isotropic magnetic susceptibilities, such as contributions from tissue microstructure and chemical exchange mechanisms.
We have recently begun to employ Deep Learning techniques to solve the inverse mathematical problem with more sophisticated magnetostatic models, taking into account contrast mechanisms that have previously been overlooked. We anticipate that the technology we have developed will have substantial clinical implications, as it will provide tissue property parameters that have not been available before. The presence of these new, clinically applicable parameters has the potential to significantly enhance diagnosis, the staging of brain lesions, and the monitoring of treatment progress in various neurological diseases, such as multiple sclerosis.

Publications


Investigating non-susceptibility contributions to GRE phase contrast


K. Sommer, F. Schweser, A. Deistung, J. Reichenbach


2011


Quantitative mapping of susceptibility and non-susceptibility frequency from gradient-echo phase images


Jochmann T, Jakimovski D, Küchler N, Zivadinov R, Haueisen J, Schweser F


12th Ultrahigh Field Magnetic Resonance Symposium , 2021, p. 13


U2-Net for DEEPOLE QUASAR–A Physics-Informed Deep Convolutional Neural Network that Disentangles MRI Phase Contrast Mechanisms.


Jochmann T, Haueisen J, Zivadinov R, Schweser F


Proc Intl Soc Mag Reson Med, Montreal, QC, Canada, 2019, p. 320


DEEPOLE QUASAR–A deep learning-based approach for quantitative susceptibility and non-susceptibility phase mapping.


Jochmann T, Haueisen J, Zivadinov R, Schweser F


5th International Workshop on MRI Phase Contrast and QSM, Seoul, Korea, 2019


A Fourier transformation based convolutional neural network layer for physics-informed deep learning of magnetic dipole inversion


Küchler N, Haueisen J, Schweser F, Jochmann T


German Society for Biomedical Engineering , 2020, p1570638759


How to train a Deep Convolutional Neural Network for Quantitative Susceptibility Mapping (QSM)


Jochmann T, Haueisen J, Schweser F


Proc Intl Soc Mag Reson Med, 2020, p. 3195


U3-Net for Deep Vector QSM – Solving the Susceptibility Tensor Phase Model in Single-Orientation MRI


Baader EF, Jochmann T, Haueisen J, Zivadinov R, Schweser F


Proc Intl Soc Mag Reson Med, 2020, p. 3202


Mapping Magnetic Susceptibility and Non-Susceptibility Sources from MRI Frequency Shift with Physics-informed Deep Learning.


Jochmann T, Schweser F, Küchler N, Jakimovski D, Zivadinov R, Haueisen J


16th International Workshop on Optimization and Inverse Problems in Electromagnetism, 2021


Quantitative mapping of susceptibility and non-susceptibility frequency with DEEPOLE QUASAR


Jochmann T, Jakimovski D, Küchler N, Zivadinov R, Haueisen J, Schweser F


Proc Intl Soc Mag Reson Med, 2021, p. 789