INTERNATIONAL TOMOGRAPHY CENTER
Siberian Branch of Russian Academy of Sciences
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Main achievements

2024


Current advances in neuroimaging offer promising alternatives to invasive intracranial pressure monitoring. This study explores magnetic resonance imaging (MRI) markers for detecting elevated intracranial pressure in patients with secondary intracranial hypertension, comparing 40 patients with brain tumors and 15 with hydrocephalus against 36 healthy controls.

The MRI protocol included detailed measurements of optic nerve sheath diameter (ONSD), pituitary gland dimensions, and optic nerve tortuosity. Hydrocephalus patients additionally underwent phase-contrast MRI to assess cerebrospinal fluid dynamics and calculate intracranial compliance. Automated brain volumetry was performed using FreeSurfer software.

Key findings revealed consistent patterns across patient groups: a 24% ONSD enlargement (p<0.05), pituitary gland flattening, and optochiasmal cistern expansion compared to controls. The hydrocephalus group showed significantly reduced intracranial compliance (1.7-fold decrease, p<0.05). Tumor patients demonstrated more frequent optic nerve tortuosity. Notably, brain volume correlated positively with ONSD in tumors (r=0.55) and negatively with compliance in hydrocephalus (r=-0.86).
These results suggest that multiparametric MRI evaluation - combining structural measurements with hydrodynamic assessments - could enhance non-invasive intracranial pressure monitoring. The identified biomarkers may help clinicians detect and monitor intracranial hypertension while avoiding invasive procedures, particularly in patients with space-occupying lesions or cerebrospinal fluid circulation disorders. The approach warrants further validation in larger clinical studies. 

Figure. Measurement of the diameter of the optic nerve sheath in the axial section on T2-WI (а); 2D_QFlow, FFE/M, axial slice at C2-C3 cervical level (б). Manually allocated regions of interest: CarIntCervR and L – right and left internal carotid arteries, VertR and L – right and left vertebral arteries, JugR and L – right and left jugular veins


Another investigation explores structural brain changes during critical recovery phases following ischemic stroke using sophisticated diffusion MRI techniques. Ten patients underwent serial 3T MRI scans at three key timepoints: acute (1-3 days), subacute (7-10 days), and early chronic (3-4 months) stages. The study employed both conventional diffusion tensor imaging (DTI) and advanced generalized q-sampling imaging (GQI) to compare affected brain regions with their unaffected contralateral counterparts.
The analysis revealed significant dynamic changes across multiple diffusion parameters, with variations ranging from 4.3% to 53.9% (p<0.05) showing strong statistical correlations (r=0.76-0.99). In stroke-affected areas, these measurements traced a progression from initial edema (marked by increased mean and isotropic diffusion values) through subsequent tissue necrosis to eventual axonal degeneration (reflected in declining anisotropy metrics). Conversely, the contralateral hemisphere demonstrated a distinct pattern suggesting edema resolution and potential compensatory neuroplastic changes.
Methodological refinements in image processing enabled more precise tracking of complex white matter pathways and boundary zone alterations. The optimized protocol improved sensitivity to the multidirectional fiber architecture surrounding stroke lesions while maintaining anatomical accuracy during longitudinal comparisons.
These quantitative diffusion metrics provide a window into the competing processes of degeneration and reorganization that characterize post-stroke recovery. The ability to non-invasively monitor these microstructural changes offers clinicians valuable insights for predicting recovery trajectories and potentially guiding rehabilitation strategies. The contralateral hemisphere's response pattern particularly highlights the brain's remarkable capacity for adaptive reorganization following injury.

Figure. The selection of 3D ROI in semi-automatic mode and its projection on the contralateral side

2023


This study explored whether real-time MRI brain training could help reduce depression symptoms as effectively as standard cognitive behavioral therapy (CBT). Researchers worked with 20 antidepressant-free adults with mild-to-moderate depression, offering either eight sessions of neurofeedback (where patients learned to control activity in a mood-related brain area) or 16 sessions of traditional CBT.

While both approaches significantly reduced depression symptoms over time, CBT showed slightly stronger effects. Interestingly, patients doing neurofeedback kept improving their brain control skills throughout all sessions without plateauing. The study provides valuable insights for future research, though its small size means we should interpret results cautiously. These findings suggest different therapeutic paths might help depression - through either direct brain training or psychological techniques - and highlight how modern neuroscience can complement established therapies.

Figure. Schematic for dataflow and experimental design. A Screenshot from rt-fMRI software (Philips iViewBOLD). On the half-split screen, statistical maps for the contrast between up- and down-regulation are shown on the left and statistics on signal fluctuation for artifact control on the right. The time courses of percentage signal change is displayed on the bottom for both RoIs. B Enlargements of the selected RoIs in one slice (green solid line for RoI; blue dashed line for control RoI). C Enlargement of the signal time courses over the volume numbers (green: target RoI; blue control RoI). Below, the blocks mark the paradigm (dark: upregulation; light: down-regulation). D RoI data are extracted and exported to an external computer where signal changes in the target area over the control area are calculated. E This score is fed back to the participants as size of a disk. Upward arrow and yellow color indicated up-regulation (40 s each); downward arrow and blue color were shown during the down-regulation condition (20 s each). F Schematic of the experimental paradigm per each of the 8 neurofeedback sessions. The first run comprised 15 trials (20-s down-regulation and 40-s up-regulation each), the second run 10 trials. *Alternating, the second run was a transfer run with no feedback.


2022


This study develops a computational framework to understand how different brain fluids—including blood (arterial, capillary, venous) and cerebrospinal fluid (CSF)—interact to influence ventricular wall movement and surrounding pressure. Using a sophisticated poroelasticity model that treats brain tissue as a porous medium, we simulated these fluid interactions through four key parameters.

Our analysis revealed that the arterial-CSF interaction exerts the strongest effect on ventricular wall displacement. The mathematical model, incorporating multiple regression analysis, successfully identified distinct parameter patterns characteristic of three neurological conditions: normal pressure hydrocephalus (a CSF circulation disorder), intracranial hypertension (elevated brain pressure), and ventriculomegaly caused by chronic low blood flow.

These findings provide new insights into the mechanical forces shaping brain ventricles in disease states. The model offers clinicians a potential tool for better understanding pressure-related brain disorders without invasive procedures, though further validation with patient data is needed. The work particularly highlights how imbalances between blood flow and CSF dynamics can lead to different pathological ventricular expansions.

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Figure. Geometry of the computational domain. Geometries of the computational domain for four volunteers

2021


This study develops a computational framework to analyze ventricular wall mechanics in normal pressure hydrocephalus (NPH) using a multiphase poroelastic model of brain tissue. The model incorporates clinical imaging data to simulate how cerebrospinal fluid dynamics affect both ventricular wall displacement and surrounding tissue pressure.

Key findings demonstrate that simplified brain geometries can effectively predict critical pressure and displacement values that would occur in more anatomically complex models. The analysis reveals how variations in model parameters influence mechanical stress distributions around the ventricles in NPH cases.

These results suggest that computationally efficient simplified models may provide clinically relevant estimates of ventricular mechanics while reducing analysis complexity. The approach offers potential for better understanding pressure-volume relationships in hydrocephalus and could inform treatment planning, though further validation with patient-specific data is needed. The study highlights how engineering modeling techniques can contribute to neurological disorder research by quantifying mechanical forces in brain tissue.

Fig. 2
Figure. Blood and CSF transfer in the parenchyma of the brain: (1) arterial territory, (2) capillary territory, (3) venous territory, (4) CSF territory, and (5) parenchyma.


2020

This study presents a computational approach to analyze fluid movement through brain tissue, examining how blood and cerebrospinal fluid interact within the cerebral environment. The model captures three key scenarios: normal fluid balance, hydrocephalic conditions with ventricular enlargement, and transitional states between them.

By adjusting fluid flow parameters, the simulations demonstrate how changes in pressure and permeability can lead to ventricular expansion seen in hydrocephalus. The analysis provides quantitative measurements of pressure distribution and fluid exchange rates throughout different brain compartments.

This framework offers new perspectives on both healthy brain fluid regulation and the development of fluid-related disorders. The model's ability to simulate transitional states may help understand disease progression and evaluate potential treatments. Future integration of patient-specific data could enhance clinical applications for neurological conditions involving fluid imbalance.

The approach builds on established principles of porous media mechanics while accounting for the brain's unique fluid dynamics, creating a versatile tool for studying cerebral fluid behavior in various physiological and pathological conditions.

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Figure. Vector visualization of virtual blood particles with directional encoding and linear velocity measurement within the human carotid artery lumen (in vivo) using 4D FLOW phase-contrast angiography on a 3 Tesla MRI scanner.