STUDY OF THE STRUCTURAL REORGANIZATION OF THE BRAIN IN THE EARLY POST-STROKE PERIOD USING METHODS BASED ON DIFFUSION MRI
Karabanov I.S.1,2, Popov V.V.1,2, Bogomyakova O.B.1,2,3,
Stankevich Y.A.1,2, Tulupov A.A.1,2,3
1 - The Institute International Tomography Center of the Russian Academy of Sciences.
2 - Novosibirsk State University.
3 - Lavrentyev Institute of Hydrodynamics. Novosibirsk, Russia.
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urpose. To study the structural reorganization of the brain in the early post-stroke period using methods based on diffusion MRI.
Materials and methods. 3 T MRI examination was used: standard scan plus diffusion sequence with DTI (diffusion tensor imaging) and GQI (generalized q-sampling imaging) post-processing. Brain structures were studied after ischemic stroke: after 1-3, after 7-10 days, after 3-4 months. Areas of stroke and identical areas of similar localization in the contralateral hemisphere were analyzed. The sample consisted of 10 patients who completed all 3 studies.
Results. Characteristics of the density of tracts, quantitative anisotropy, fractional anisotropy, axial, mean, radial, isotropic and restricted diffusion in dynamics significantly (p<0,05) changed (4,3-53,9%) and showed a strong (0,76-0.99 r) Spearman correlation, which characterizes them as key quantitative metrics of DTI/GQI analysis.
Discussion. DTI and GQI post-processing have been optimized: image normalization, selection of sensitivity to the multidirectionality of the fiber path, registration of the complex spatial architecture of stroke and contralateral areas, selection of boundary conditions for constructing tractography.
Conclusions. The dynamics of key quantitative diffusion parameters and tractography in the early post-stroke period indicate a number of degenerative processes in the area of stroke (edema – mean and isotropic diffusion; necrosis – mean diffusion; decrease in axonal density – quantitative anisotropy, axial diffusion; loss of axons – quantitative and fractional anisotropy), and in the contralateral hemisphere with a tendency to restore the values of the metrics, presumably due to the reduction of edema (mean and isotropic diffusion) and neurogenesis processes (density of tracts).
Keywords: ischemic stroke, magnetic resonance imaging, diffusion tensor imaging, generalized q-sampling imaging.
Corresponding author: Karabanov I.S, e-mail: Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript
For citation: Karabanov I.S., Popov V.V., Bogomyakova O.B., Stankevich Y.A., Tulupov A.A. Study of the structural reorganization of the brain in the early post-stroke period using methods based on diffusion MRI. REJR 2023; 13(3):14-29. DOI: 10.21569/2222-7415-2023-13-3-14-29.
Received: 19.06.23 Accepted: 07.09.23