• Background
  • Background

    Modern brain imaging has dramatically advanced our understanding of ischemic stroke. The application of magnetic resonance imaging (MRI) and computed tomography (CT) is the cornerstone of diagnosis and management of acute stroke. The innovations in multimodal MRI continue to shape our knowledge of stroke pathophysiology.

    In clinical practice, the combination of diffusion weighted imaging (DWI), perfusion imaging (PI) and MR-angiography guides individual therapeutic decisions by visualizing infarcted brain areas, tissue at risk of infarction and vessel occlusions. By this, multiparametric MRI enables in individually tailored treatment decisions based on information on brain tissue and vessel status. Diffusion tensor imaging (DTI) further allows the characterization of neuronal fiber tracts. Functional MRI (fMRI) measures brain activity by detecting associated changes in blood flow and can be used to detect alterations in brain activation parameters resulting from functional reorganization.

    Current research involves the integration of multiparametric imaging techniques with clinical information, behavioral parameter, and complimentary information from electrophysiological studies using transcranial magnetic stimulation (TMS) or EEG using state of the art methods of computational neuroscience, e.g. to study alterations in brain network properties following focal brain damage resulting from ischemic stroke.

  • Characterization of pathophysiology of acute ischemic stroke using multiparametric MRI

    We study changes in brain vessel status, perfusion, and tissue in acute stroke using multiparametric MRI including DWI, DTI, PI, MR-angiography. The interplay between brain perfusion and tissue damage is analysed, and characteristic findings can be used to define tissue compartments relevant for tissue outcome and treatment decisions. This includes approaches to identify tissue at risk of infarction by PI-DWI-mismatch or blood oxygen level dependent (BOLD) imaging and the characterization of time signatures of acute vertebral ischemia that resulted in the suggestion of the concept of DWI-FLAIR mismatch.

    Use of multiparametric MRI to guide individualized acute stroke treatment

    We aim to optimize acute stroke treatment and patient selection for specific treatment options such as thrombolysis by using results from multiparametric MRI. For this purpose, we aim at a quick transfer of basic stroke imaging research into clinical trials or daily practice. This has resulted in observational studies of MRI guided thrombolysis in an extended time window or the identification of criteria to predict the development of space-occupying "malignant" middle cerebral artery stroke. Recently, we have initiated a European randomized controlled trial of MRI based thrombolysis in stroke patients with unknown time of symptom onset (WAKE-UP) which is funded by the European Commission within FP7.

    Lesion-behavior mapping and outcome prediction in stroke

    We use information from multimodal MRI to evaluate the potential to predict behavioural symptoms and clinical outcomes from stroke lesions. For this purpose we study both acute and chronic stroke patients by structural MRI and DTI in studies of lesion inference. We also study the impact of damage to specific brain regions or systems such as the corticospinal tract.

    Brain reorganization and motor recovery after ischemic stroke

    We analyze structural brain tissue properties in the acute and chronic phase of ischemic stroke by MRI sequences used in clinical routine (DWI, PI, Angiography) and research (DTI and fMRI). We aim to gain further insides into the dynamic of neuronal plasticity during stroke rehabilitation focusing on the brain motor system. We are part of the SFB936 (Multisite communication in the brain). In complimentary studies we have applied the combination of structural and functional MRI to study alterations in the sensory-motor network in patients with Tourette's syndrome.

Projects

We are engaged in clinical trials and primary research studies. Here you find detailed information about our current work.


Publications

Here you find selected publications with authorships of members from our research group during the last 15 years.