Phase-based metamorphosis of diffusion lesion in relation to perfusion values in acute ischemic stroke.
Examining the dynamics of stroke ischemia is limited by the standard use of 2D-volume or voxel-based analysis techniques. Recently developed spatiotemporal models such as the 4D metamorphosis model showed promise for capturing ischemia dynamics. We used a 4D metamorphosis model to evaluate acute ischemic stroke lesion morphology from the acute diffusion-weighted imaging (DWI) to final T2-weighted imaging (T2-w). In 20 representative patients, we metamorphosed the acute lesion to subacute lesion to final infarct. From the DWI lesion deformation maps we identified dynamic lesion areas and examined their association with perfusion values inside and around the lesion edges, blinded to reperfusion status. We then tested the model in ten independent patients from the STroke Imaging Repository (STIR). Perfusion values varied widely between and within patients, and were similar in contracting and expanding DWI areas in many patients in both datasets. In 25% of patients, the perfusion values were higher in DWI-contracting than DWI-expanding areas. A similar wide range of perfusion values and ongoing expansion and contraction of the DWI lesion were seen subacutely. There was more DWI contraction and less expansion in patients who received thrombolysis, although with widely ranging perfusion values that did not differ. 4D metamorphosis modeling shows promise as a method to improve use of multimodal imaging to understand the evolution of acute ischemic tissue towards its fate.
Division of Neuroimaging Sciences, Brain Research Imaging Centre, University of Edinburgh, UK ; Brain Research Imaging Centre, SINAPSE Collaboration, UK ; CMAP, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau, France.
Islem
I
Rekik
CMAP, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau, France.
Stéphanie
S
Allassonnière
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA ; Seton/UT Southwestern Clinical Research Institute of Austin, Department of Neurology and Neurotherapeutics, UT Southwestern Medical Center, Austin, TX, USA.
Marie
M
Luby
Division of Neuroimaging Sciences, Brain Research Imaging Centre, University of Edinburgh, UK ; Brain Research Imaging Centre, SINAPSE Collaboration, UK.
Trevor K
TK
Carpenter
Division of Neuroimaging Sciences, Brain Research Imaging Centre, University of Edinburgh, UK ; Brain Research Imaging Centre, SINAPSE Collaboration, UK.
Joanna M
JM
Wardlaw
D000208:Acute Disease; D000368:Aged; D001921:Brain / Q000473:pathology*; D002545:Brain Ischemia / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D020521:Stroke / Q000473:pathology*
Diffusion imaging; Ischemic stroke; Lesion evolution; Magnetic resonance imaging; Metamorphosis; Perfusion imaging