Not All Lesioned Tissue Is Equal: Identifying Pericavitational Areas in Chronic Stroke With Tissue Integrity Gradation via T2w T1w Ratio.

Autor:	Krishnamurthy LC; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, GA, United States.; Department of Physics and Astronomy, Georgia State University, Atlanta, GA, United States., Krishnamurthy V; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, GA, United States.; Division of Geriatrics and Gerontology, Department of Medicine, Emory University, Atlanta, GA, United States.; Department of Neurology, Emory University, Atlanta, GA, United States., Rodriguez AD; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, GA, United States.; Department of Neurology, Emory University, Atlanta, GA, United States., McGregor KM; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, GA, United States.; Department of Neurology, Emory University, Atlanta, GA, United States., Glassman CN; Department of Nuclear and Radiological Engineering and Medical Physics, Georgia Institute of Technology, Atlanta, GA, United States., Champion GS; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, GA, United States.; Department of Psychology, Georgia State University, Atlanta, GA, United States., Rocha N; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, GA, United States., Harnish SM; Department of Speech and Hearing Science, The Ohio State University, Columbus, OH, United States., Belagaje SR; Department of Neurology, Emory University, Atlanta, GA, United States.; Department of Rehabilitation Medicine, Emory University, Atlanta, GA, United States., Kundu S; Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA, United States., Crosson BA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, Decatur, GA, United States.; Department of Neurology, Emory University, Atlanta, GA, United States.; Department of Psychology, Georgia State University, Atlanta, GA, United States.
Jazyk:	angličtina
Zdroj:	Frontiers in neuroscience [Front Neurosci] 2021 Aug 05; Vol. 15, pp. 665707. Date of Electronic Publication: 2021 Aug 05 (Print Publication: 2021).
DOI:	10.3389/fnins.2021.665707
Abstrakt:	Stroke-related tissue damage within lesioned brain areas is topologically non-uniform and has underlying tissue composition changes that may have important implications for rehabilitation. However, we know of no uniformly accepted, objective non-invasive methodology to identify pericavitational areas within the chronic stroke lesion. To fill this gap, we propose a novel magnetic resonance imaging (MRI) methodology to objectively quantify the lesion core and surrounding pericavitational perimeter, which we call tissue integrity gradation via T2w T1w ratio (TIGR). TIGR uses standard T1-weighted (T1w) and T2-weighted (T2w) anatomical images routinely collected in the clinical setting. TIGR maps are analyzed with relation to subject-specific gray matter and cerebrospinal fluid thresholds and binned to create a false colormap of tissue damage within the stroke lesion, and these are further categorized into low-, medium-, and high-damage areas. We validate TIGR by showing that the cerebral blood flow within the lesion reduces with greater tissue damage ( p = 0.005). We further show that a significant task activity can be detected in pericavitational areas and that medium-damage areas contain a significantly lower magnitude of hemodynamic response function than the adjacent damaged areas ( p < 0.0001). We also demonstrate the feasibility of using TIGR maps to extract multivariate brain-behavior relationships ( p < 0.05) and show general agreement in location compared to binary lesion, T1w-only, and T2w-only maps but that the extent of brain behavior maps may depend on signal sensitivity as denoted by the sparseness coefficient ( p < 0.0001). Finally, we show the feasibility of quantifying TIGR in early and late subacute stroke phases, where higher-damage areas were smaller in size ( p = 0.002) and that lesioned voxels transition from lower to higher damage with increasing time post-stroke ( p = 0.004). We conclude that TIGR is able to (1) identify tissue damage gradient within the stroke lesion across different post-stroke timepoints and (2) more objectively delineate lesion core from pericavitational areas wherein such areas demonstrate reasonable and expected physiological and functional impairments. Importantly, because T1w and T2w scans are routinely collected in the clinic, TIGR maps can be readily incorporated in clinical settings without additional imaging costs or patient burden to facilitate decision processes related to rehabilitation planning. Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. (Copyright © 2021 Krishnamurthy, Krishnamurthy, Rodriguez, McGregor, Glassman, Champion, Rocha, Harnish, Belagaje, Kundu and Crosson.)
Databáze:	MEDLINE
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