Research Group Leader

Dr. Anke Henning
Dr. Anke Henning
Phone: +49 7071 601-723
Fax: +49 7071 601-702
Opens window for sending emailanke.henning[at]tuebingen.mpg.de
 

More about the Research Group

 

MR Spectroscopy and Ultra-High Field Methodology

Shortly after introduction of in vivo magnetic resonance imaging (MRI) also first localized in vivo magnetic resonance spectra (MRS) were acquired in the early 1980s. In vivo MRS has evolved during the last 25 years in terms of localization quality and spatial resolution, acquisition speed, artifact suppression, number of detectable metabolites and quantification precision and has profited especially from the significant increase of magnetic field strength that recently became available for in vivo investigations. Today it allows for non-invasive and non-ionizing determination of tissue concentrations and metabolic turn-over rates of various metabolites and compounds in animals or humans, is applied for clinical diagnostics and has established as an important tool for physiological research.

 

 

 

 

Magnetic Resonance Spectroscopy Methodology

To draw physiologically meaningful conclusions spectroscopy results need to be spatially and metabolically specific and all confounding factors related to acquisition, reconstruction and quantitative analysis need to be considered and artifact sources controlled to obtain reliable and reproducible results. To that a high localization accuracy and efficiency including coherence pathway selection and motion compensation methods need to be developed. Calibration steps such as flip angle optimization or B0 shimming have to be robust. Quantification has to be based on spectral fitting algorithms exhibiting robust convergence and include comprehensive prior-knowledge and stable reference standards. In addition, acquisition times need to be shortened by different acceleration techniques for clinical use, spectroscopic imaging with whole organ coverage at high spatial resolutions and functional magnetic resonance spectroscopy.

Current projects of specific interest include

        spectroscopy localization

        Opens external link in new windowaccelerated MRSI and related Opens external link in new windowMRSI reconstruction

        Opens external link in new windowfunctional 1H and 13C MRS

        motion correction methods for body MRS (Opens external link in new windowspinal cord, Opens external link in new windowmyocardium)

        Opens external link in new window2D resolved and edited MRS

        Opens external link in new windowspectral fitting

       Opens external link in new windowERETIC reference standard

 

Ultra-high field magnetic resonance methodology

The higher the static magnetic field strength the higher are spectral separation and signal-to-noise ratio, which results in a largely increased number of detectable metabolites at high spatial specificity at ultra-high field strength. However, the advantages of high (3T) and ultra-high (7T) field strength come along with extensive technical challenges such as inhomogeneous transmit (B1) fields due to standing wave effects, an increased impact of microscopic and macroscopic susceptibility differences on static magnetic field (B0) inhomogeneity, shortened T2 and lengthened T1 relaxation times, lower effective B1 field strength and scan time prolongation due to specific-absorption-rate restrictions. In addition respiratory motion induces time dependent B0 field fluctuations which need to be addressed to extend the applicability of in vivo MRS to a larger number of organs. The aim of our ultra-high field methods development projects is hence to overcome these technical challenges in order to extend the number of quantifiable metabolites and to increase spatial resolution and hence specificity. In general related methodology can be transferred to additional MR imaging modalities.

Current projects of specific interest include

·         Opens external link in new windowradiofrequency pulse design

·         parallel transmit and receive technology (Opens external link in new windowRF coil arrays, Opens external link in new windowEM simulation and optimization)

·         Opens external link in new windowreal-time feedback, dynamic, higher order Opens external link in new windowB0 shim technology

 

Multimodal high-field MRS and MRI for physiological research

Newly developed magnetic resonance spectroscopy methodology may enable a more profound understanding of healthy and pathological physiology. Hence these methods are evaluated with respect to their relevance for clinical diagnostics and combined with structural and functional MRI modalities such as high resolution anatomical imaging, resting-state functional connectivity imaging, perfusion imaging, diffusion weighted imaging or complementary non-MR  imaging methodology such as PET for physiological or pathophysiological studies. Physiological studies usually require assessment of additional biomarkers and may benefit from a translational approach in humans and animals.

Physiological studies are typically joint projects with collaborators with physiological or clinical background and/or expertise in a complementary imaging method.

Current physiological studies focus on the following topics:

       Opens external link in new windowPsychiatric Disorders: major depressive disorder and mechanism of action of related

       therapy forms

        Opens external link in new windowNeurological Disorders: spinal cord pathology and regeneration

        Opens external link in new windowMuscle physiology: skeletal and myocardial muscle energy metabolism in metabolic

       syndrome

 


The MR Spectroscopy and Ultra-High Field Methodology research group is currently moving to the MPI for Biological Cybernetics from the Opens external link in new windowInstitute of Biomedical Engineering / University and ETH Zurich, Switzerland.

Last updated: Thursday, 26.02.2015