Ongoing Projects

Potassium MRI and MRS

In close collaboration with the Nephrology department, this SISF- and SNF-funded project develops non-invasive MRI and spectroscopic imaging methods to quantify intracellular potassium in human muscle and liver. Using ultrahigh-field 39K-MRI, the approach enables spatially resolved investigation of potassium homeostasis, which is not accessible with conventional clinical measurements. The methods are validated in volunteers through exercise and potassium-loading studies, and applied in patients with hypertension and chronic kidney disease. The goal is to characterize inter- and intra-individual variability and detect disease-related alterations in tissue potassium. These measurements will improve understanding of potassium regulation and support clinical research and therapeutic monitoring.

Metabolic investigations of mitochondrial and related disorders by NMR in cell cultures.

This SNF-funded project uses advanced NMR techniques, including HR-MAS, to investigate metabolic alterations in mitochondrial and related disorders in intact cell systems. By combining metabolomic profiling of low molecular weight molecules including many metabolites involved in cellular respiration in intact cells with measurements of energy status, pH, oxygenation, and reactive oxygen species, the approach enables detailed characterization of cellular metabolism.

A novel perfused bioreactor system allows real-time monitoring of metabolic responses under controlled conditions and stress. The study aims to distinguish different mitochondrial defect subgroups and understand their biochemical mechanisms. Ultimately, this platform supports improved diagnostics and evaluation of therapeutic strategies.

Ex-situ heart perfusion (ESHP) in DCD heart transplantation

This SNF-funded project investigates strategies to improve heart preservation and evaluation in donation-after-circulatory-death (DCD) transplantation using ex-situ heart perfusion (ESHP). The overall project brings together the complementary expertise of Cardiac Surgery (Prof. Longnus, lead), Cardiovascular Anaesthesiology (Prof. Günsch), and MR-Methodology (Prof. Vermathen).

Combining advanced imaging techniques with translational models, the study explores mechanisms of graft injury and cardioprotection. The goal is to optimize transplantation protocols and improve graft quality, with a focus on pediatric patients. To address this, in our part of the project we aim to investigate perfused hearts directly inside an ultra-high field MR scanner, using advanced metabolic imaging and spectroscopy techniques, specifically deuterium metabolic imaging (DMI) and phosphorus 31P-MR spectroscopy, to enable advanced, non-invasive assessment of cardiac metabolism and viability. In addition, high resolution (HR) NMR measurements of ex-situ perfusate samples will be performed to determine biomarkers and to predict graft outcome.

The findings are expected to enhance clinical outcomes and expand donor organ availability.

Non-invasive assessment of bile acid composition in gallbladder and liver tissue

This project develops a non-invasive method to quantify bile acid composition in the gallbladder and liver using proton MR-spectroscopy at 7 Tesla. Due to the high spectral resolution of ultra-high field MRS, the approach improves detection and quantification of bile-related metabolites compared to conventional MRI systems. The study aims to assess measurement reproducibility and variability and focuses on patients with cholestasis. This enables better understanding of disease mechanisms and monitoring of progression and treatment response. The method has potential to support diagnosis and development of new therapies for cholestatic liver diseases.

Elucidation of downfield 1H MR spectrum

In projects with Johns Hopkins Univesity in Baltimore, USA (Prof. Peter Barker) and the Center for Biomedical Imaging (CIBM) in Lausanne peak assignments, diffusion properties and exchange times of signals appearing in the downfield part (>4.7 ppm) of the in vivo proton brain spectrum are investigated and their potential role for clinical 1H MRS is explored

 

Diffusion weighted MR spectroscopy of the brain and prostate

Diffusion weighted imaging is a well established tool in clinical MRI, but also for the investigation of brain microstructure in neuroscience. In our collaborations with CUBRIC (Cardiff University, GB), Mac Planck Institute for Human Cognitive and Brain sciences (Leipzig, D), Radboud University (Nijmegen, NL), the Center for Biomedical Imaging (CIBM) in Lausanne and NYU Langone Health (New York, USA) diffusion weighted spectroscopy is optimized and explored as a tool for a cell-specific microstructure analysis in the brain and the prostate.

 

Image Acquisition and Reconstruction in Quantitative MRI (qMRI)

qMRI allows to measure absolute properties of tissues, like T1 and T2 relaxation times, such that interpretation of the images is not only based on contrast between structures, but the image intensity represents a magnetic property of the tissue itself. The goal of qMRI is to discern between healthy and diseased tissue or to better characterize diseased tissue based on the measured quantitative parameters. Conventional methods offer limited anatomical coverage and require long scan time, as a result qMRI is mainly used in research settings.

In close collaboration with the Swiss Innovation Hub of Siemens Healthineers we develop novel imaging methods for mapping T1, T2 and T1ρ relaxation times with high resolution and full-organ coverage. The aim of these prototypes is to be fast and robust to be ultimately used in clinical workflows. Our research and developments focus on:

  • RF pulses and MR sequence design
  • Fast acquisition and reconstruction strategies (compressed sensing and deep learning)
  • Fast parameter mapping routines (dictionary and model based)
  • Validation for various organs (brain, knee, hip and prostate)
  • Translation of methodology from high to ultra-high fields (3 T to 7 T)
  • Dissemination with international partners for evaluation in clinical studies

Figure: general workflow of the QuantoRAGE MR sequence for dictionary-based simultaneous T1 and T2 mapping of the full brain at 3 T.