Embedded Files
Principle Investigator
Siawoosh Mohammadi
Siawoosh Mohammadi
siawoosh.nathomohammadi(at)uni-luebeck.de
➡️Profil
"Understanding the basic mechanisms underlying both normal and diseased brain development begins with reliable insight into the brain’s anatomical connectivity and microstructure - such as cell size, myelin density, fiber density, and the g-ratio (the ratio of the inner to outer diameter of a fiber).
My long-term goal is to non-invasively estimate these microstructural properties in living subjects. My tools are: MRI and physics, biophysical models and machine learning. To bridge the scale gap between in vivo MRI and the microscopic measures of interest, I also enjoy collaborating with partners who use MRI microscopy and 3D ex vivo histology."
Postdocs
Francisco J. Fritz
Francisco J. Fritz
"My research lies in pushing the boundaries of MRI, particularly for ex vivo human imaging. I specialize in tailoring MR sequences to capture the intricate details of human anatomy, both in vivo and ex vivo. Delving into the realm of diffusion and relaxometry MR images, my research focuses on sophisticated analysis and modeling. This approach allows us to unravel the complexities of tissue microstructure, providing a detailed understanding of the composition and behavior of biological tissues at a microscopic level. Bridging the gap between research and practical applications, my efforts extend to clinical realms. I leverage optimized MR sequences and microstructure analysis techniques to contribute to the characterization of microstructures associated with epilepsy and tumors. This has significant implications for improving diagnostic precision and tailoring treatment strategies for better outcomes in these critical medical areas. Committed to the growth of the scientific community, I actively engage in the supervision of Master's and PhD students. Guiding the next generation of researchers, I aim to instill a passion for innovation, critical thinking, and excellence in scientific exploration."
f.lagosfritz@uke.de
Jan Malte Oeschger
Jan Malte Oeschger
"My focus lies in disentangling the complexities of accurate DKI parameter estimation amidst the challenges posed by noise. Through extensive simulations of the diffusion MRI signal in various tissue types influenced by noise I explored the effects of different DKI models, including the standard and axisymmetric variations and Rician bias correction and additionally characterized the model inherent bias introduced by the simplifications made in axisymmetric DKI.
Beyond this, my work extends to biophysical parameter estimation, grounded in the “Standard model” whose parameters offer tissue specific, biological insights. Here the crux lies in navigating noise in DKI whose parameters are used to estimate the biophysical parameters. Accurate DKI parameters pave the way for accurate biophysical parameter estimates.
One use case of biophysical parameters that I am working on is g-ratio mapping. The g-ratio is a geometrical invariant with high functional relevance because it is linked the neuronal conduction velocity and relies on accurate estimation of the axonal water fraction which is one of the biophysical parameters."
moeschge@physnet.uni-hamburg.de
PhDs
Björn Fricke
Björn Fricke
"My project aims at helping to develop a user-friendly open-source toolbox denoted ACID for more reproducible and standardized usage of diffusion MRI in the spinal cord, for post-mortem samples, and the brain in neuroscience and clinical research studies.
To achieve this, the following aspects of the existing prototype of the ACID toolbox will be enhanced:
a) Improving the functionality and making it more user-friendly (e.g., by adding BIDS support).
b) Addition of new features such as optimizing all ACID modules for applications into the spinal cord and post-mortem.
c) Better understanding of noise which is important for the correct performance of denoising and rician bias correction. "
bjoern.fricke@uksh.de
Laurin Mordhorst
Laurin Mordhorst
"My goal is to make MRI-based characterization of axons, the telephone cables of the human brain, accessible for clinical and neuroscience research. In particular, I quantify the radii of axons, which are related to the speed of information transfer; hence, axon radii quantification using non-invasive MRI-based methods may help quantify brain structure, function and health.
On one hand, I am improving the histological gold standard for MRI-based axon radii estimation by analzing large microscopy images including of millions axons using deep-learning based segmentation approaches. On the other hand, I am validating current models for MRI-based axon radii estimation against our new histological gold standard to assess feasibility and caveats of current modeling approaches, thereby contributing towards establishing the MRI-based axon radius estimates as a biomarker for the human brain."
laurin.mordhorst@uksh.de
Nina Lüthi
Nina Lüthi
"My project aims to explore discrepancies in ex-vivo diffusion-weighted images of entire human brains compared to in-vivo human brains. Ex-vivo samples hold significant value for obtaining high-resolution images that can be compared either with living brains or histological counterparts. Ideally, these samples would mirror one another, but factors such as fixation and post-mortem interval can introduce variations.
"My project aims to explore discrepancies in ex-vivo diffusion-weighted images of entire human brains compared to in-vivo human brains. Ex-vivo samples hold significant value for obtaining high-resolution images that can be compared either with living brains or histological counterparts. Ideally, these samples would mirror one another, but factors such as fixation and post-mortem interval can introduce variations.
Therefore, my research focuses on investigating the longitudinal impact of formaldehyde fixation on diffusion-weighted images of whole human brains. Potential effects of fixation may alter the microstructure, posing challenges in comparing ex-vivo and in-vivo diffusion MRI data. Consequently, it is crucial for my work to assess and account for these influences in ex-vivo models."
Therefore, my research focuses on investigating the longitudinal impact of formaldehyde fixation on diffusion-weighted images of whole human brains. Potential effects of fixation may alter the microstructure, posing challenges in comparing ex-vivo and in-vivo diffusion MRI data. Consequently, it is crucial for my work to assess and account for these influences in ex-vivo models."
nina.luethi@uni-luebeck.de
Laura Bogs
Laura Bogs
laura.bogs@uni-luebeck.de
Jan Meyer
Jan Meyer
jan.meyer@uni-luebeck.de
Alumni
- Alexander Crabbe
- Tobias Streubel
- Dr. Isabel Ellerbrock
- Joshua Engels
- Sara Holm
- Hatice-Kübra Ögreten
- Annkristin Lange
- Christoph Nicolai
- Dr. Thibault Tabarin
- Prof. Dr. M. Hassan Farsbaf Shaker
Page updated
Google Sites
Report abuse