Diffusion Spectroscopy in Stroke
Condition: ISCHEMIC STROKE
MeSH terms: Stroke; Ischemic Stroke
Study type: Interventional

Summary: 
      Cerebral vascular disorder is one of the most fatal diseases despite current advances in
      medical science. The large number of negative clinical trials on neuroprotection in acute
      stroke is a pointer to the fact that translating better understanding of the pathogenesis and
      pathophysiology to clearly beneficial treatment strategies remains a daunting task. This
      project aims at elucidating the plausible biophysical events that affect water and metabolite
      diffusion in brain tissue after ischemia, by combining the information provided by two
      advanced methods of magnetic resonance (MR) diffusion imaging: diffusional kurtosis imaging
      and diffusion-weighted spectroscopy.

      Diffusion weighted imaging (DWI) has been established as a major tool for the early detection
      of stroke. However, information obtained using conventional DWI may be incomplete.
      Diffusional kurtosis (K) is a quantitative measure of the complexity or heterogeneity of the
      microenvironment in white and grey matter, which offers complementary information and may
      potentially be a more sensitive biomarker for probing pathophysiological changes. In
      addition, to gain more specific insights into molecular mobility in the intracellular
      environment, it is beneficial to assess the diffusion properties of metabolites, such as
      N-acetylaspartate (NAA), creatine and phosphocreatine (Cr), and choline containing compounds
      (Cho). Assessment of metabolite diffusion changes by diffusion-weighted spectroscopy (DWS)
      provides information specific to the intracellular environment. In particular, thanks to the
      specific compartmentation of NAA almost exclusively in neurons and of Cho in glial cells, the
      diffusion properties of these metabolites may provide specific insights into the pathological
      processes occurring independently in the two cell types. In addition, measuring a temporal
      profile of diffusion coefficient of these compounds may help clarify underlying
      pathophysiological changes in neuronal cells during acute ischemia.

      With the help of these two advanced methods, a proof-of-concept trial is proposed on 24
      healthy subjects and 24 ischemic stroke patients. Ischemic stroke patients will be scanned
      three times with a 3T MR scanner (before day 10 post-stroke, around week 4 and 3 months), in
      order to extract diffusion kurtosis imaging (DKI) and DWS metrics and understand the dynamics
      of the cellular mechanisms at play in cerebral ischemia. The goal of this study is to
      investigate neuronal and glial metabolite diffusion changes at different time points after
      ischemic stroke, in both infarcted and non-infarcted hemispheres. The aim is to get
      non-invasively important information on the evolution of the cellular damage in this disease,
      and possibly distinguishing between neuronal and glial processes (by measuring the metrics
      extracted for these two sequences), as well as on the different mechanisms leading to
      metabolite diffusion changes in the two brain areas, thus providing a great impact on the
      strategy of treatment for patients with cerebral infarction.
    


Intervention name(s): Magnetic resonance imaging
Intervention type(s): Device
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other