[Perifocal edema and glymphatic system dysfunction: quantitative assessment based on diffusion tensor magnetic resonance imaging]. / Peritumoroznyi otek i disfunktsiya glimfaticheskoi sistemy golovnogo mozga: kolichestvennaya otsenka na osnove diffuzionno-tenzornoi MRT.

BACKGROUND: Pathogenesis of peritumoral cerebral edema is unclear and potentially associated with glymphatic system dysfunction. Diffusion tensor MRI (DT-MRI) with analysis of ALPS (Analysis along the Perivascular Space) index may be valuable for assessment of edema. This approach visualizes fluid flow along perivascular spaces of deep cerebral veins. OBJECTIVE: To assess glymphatic system function in supratentorial tumors and healthy volunteers using DT-MRI. MATERIAL AND METHODS: There were 52 patients (59% men) aged 43 (28-64) years with supratentorial tumors (meningioma - 20, grade 3-4 glioma - 15, metastases - 9, lymphoma - 8). Tumors and perifocal edema did not involve deep cerebral veins. The control group included 6 healthy volunteers aged 34-66 years. MRI protocol (Signa HDxt, 3 T) contained standard T1, T2, T2FLAIR, DWI and post-contrast T1 (3D BRAVO). DT-MRI had the following parameters: TR=10 000 ms, TEmin=102 ms, FOV=240 mm, isotropic voxel size 3×3×3 mm3, 60 directions of diffusion gradients. Measurements were carried out at b-factor 0 and 1000 s/mm2. Analysis was carried out in the ReadyView software. RESULTS: Right- and left-sided ALPS indices were similar in the control group (p=0.917). Perifocal edema (regardless of histological type of tumor) in the ipsilateral hemisphere was accompanied by significantly lower ALPS index (p<0.005), while these values in contralateral (intact) hemisphere were similar in both groups (p=0.7). CONCLUSION: We found significantly lower ALPS index in deep parts of the affected hemisphere in patients with perifocal edema. These data can indicate the role of glymphatic system dysfunction in pathogenesis of this pathology.

[Factors influencing peritumoral edema in meningiomas: CT- and MRI-based quantitative assessment]. / Peritumoroznyi otek pri meningiomakh i faktory, vliyayushchie na ego formirovanie: kolichestvennaya otsenka na osnove KT i MRT.

Background. Meningiomas may be accompanied by peritumoral edema. Incidence and pathogenesis of edema are nor clearly established. Prevalence and severity of edema vary significantly in patients with meningiomas similar in various parameters. OBJECTIVE: To assess peritumoral edema in intracranial meningiomas and factors influencing incidence and severity of this process. MATERIAL AND METHODS: There were 126 patients (69% women) aged 19-76 years (median 53), who were diagnosed with 142 meningiomas. Patients underwent surgery (n=111) and radiotherapy (n=15) in 2016-2018. The MRI protocol included T1, T2, T2-FLAIR, DWI and post-contrast T1-weighted images in three projections, diffusion tensor MRI in 27 cases and MR spectroscopy in 21 patients. RESULTS: Peritumoral edema was detected in 46% (n=66) of cases including 21 (31%) patients with severe edema. The ALPS index was 1.510±0.1931 in meningiomas without edema and 1.308±0.19 in those with edema (p=0.014). There was positive correlation between edema, dimensions and uneven contours of meningioma, as well as negative correlation with CSF cleft sign. Blood flow velocity was higher in atypical and anaplastic meningiomas with edema (p=0.03). Other signs (localization, histological variant, malignancy grade, characteristics of MR signal, peaks of the main metabolites, diffusion and perfusion parameters of tumor) did not significantly affect peritumoral edema in patients with meningiomas (p>0.05). CONCLUSION: Diffusion tensor tomography with ALPS index revealed significant effect of glymphatic system dysfunction on peritumoral edema. Large meningioma with uneven contours increased the risk of peritumoral edema, while CSF cleft sign reduced this risk. Other factors did not affect cerebral edema in meningiomas.

[Periventricular changes following hydrocephalus: quantitative MR-based assessment of tissue characteristics]. / Periventrikulyarnye izmeneniya pri gidrotsefalii: kolichestvennaya otsenka tkanevykh kharakteristik metodom magnitno-rezonansnoi tomografii.

OBJECTIVE: To study tissue characteristics of periventricular white matter in patients with open hydrocephalus using DWI MRI and their correlations with CSF flow parameters. MATERIAL AND METHODS: MRI was performed in 55 patients (35 women and 20 men) with open normal pressure hydrocephalus, as well as 16 patients with malignant occlusive hydrocephalus and interstitial edema (control group). We determined the correlations between severity of hydrocephalus, periventricular lesions and CSF flow parameters considering MR data. Dimensions of ventricular system were assessed using the Evans' index, periventricular changes - using visual four-level scale with calculation of apparent diffusion coefficient (ADC) and fractional anisotropy coefficient (FA). RESULTS: Among patients with open hydrocephalus, ACD range for periventricular white matter was 1.57±0.15·10-3 mm2/s in subgroup of patients without periventricular changes (n=29) and 1.62±0.11×10-3 mm2/s in patients with periventricular changes (n=26). In the control group, mean ADC was 1.76±0.18·10-3 mm2/s (p<0.05). In patients with open hydrocephalus, FA coefficient in the areas of periventricular changes was 0.70-0.80, in case of occlusive hydrocephalus - 0.68-0.82. There was a significant relationship between the Evans' index and CSF pulsation velocity amplitude, Evans' index and stroke volume, Evans' index and cerebral aqueduct cross-sectional area in patients with open hydrocephalus. Periventricular changes were pronounced in patients with open hydrocephalus and Evans' index > 0.4 (p<0.05). CONCLUSION: According to MR data, periventricular changes in patients with open hydrocephalus differ from true periventricular interstitial edema following occlusive hydrocephalus. Severity of periventricular changes in patients with open hydrocephalus depends on patient age and width of the ventricles, but does not correlate with CSF flow parameters. In our opinion, periventricular changes are associated with dysfunction of glymphatic system. Further research is required to study the functioning of glymphatic system and related processes.

[Intracellular pH measurement in glioblastoma cells: the possibilities of phosphorus-31 MR spectroscopy]. / Izmerenie vnutrikletochnogo vodorodnogo pokazatelya glioblastom: vozmozhnosti fosfornoi magnitno-rezonansnoi spektroskopii.

OBJECTIVE: To analyze intracellular pH measurement with phosphorus-31 MR spectroscopy in glioblastoma cells and to compare these data with intracellular pH in healthy volunteers. MATERIAL AND METHODS: There were 10 patients aged 41 - 67 years with supratentorial glioblastomas. Intracellular pH in glioblastoma cells was compared with pH in healthy persons. RESULTS: We found a tendency to increased intracellular pH in glioblastoma cells in comparison with pH in intact brain tissue. CONCLUSION: Intracellular pH in brain tissue can be used as a potential marker of early abnormalities which could not be detected by conventional MRI. Moreover, these data may be valuable to estimate the efficacy of chemotherapy. The study was supported by Russian Science Foundation (grant No. 18-15-00337).

[Modern standards for magnetic resonance imaging of the brain tumors]. / Sovremennye standarty MRT-diagnostiki opukholevykh porazhenii golovnogo mozga.

Neuroimaging is essential in survey of patients with brain tumors. An important objectives of neuroimaging are highly reliable non-invasive diagnosis, treatment planning and evaluation of treatment outcomes. Magnetic resonance imaging (MRI) is one of the modern neuroimaging methods. This technique ensures analysis of structural cerebral changes, vascular and metabolic characteristics of brain tumors. It is necessary to standardize imaging parameters and unify protocols and methods considering a widespread use of MRI for brain tumors. In our practice, we use our own experience, world literature data and evidence-based international guidelines on the diagnosis of various brain diseases. The purpose of this review is to study the modern principles of magnetic resonance imaging in adults with brain tumors in neurosurgical practice.

[Diffusion kurtosis imaging in diffuse axonal injury]. / Izmeneniia parametrov diffuzionno-kurtozisnoi MRT u patsientov s diffuznym aksonal'nym povrezhdeniem.

Diffuse axonal injury (DAI) is one of the most severe traumatic brain injuries. The availability of neuroimaging biomarkers for monitoring expansion of traumatic brain injury in vivo is a topical issue. PURPOSE: To evaluate novel neuroimaging biomarkers for monitoring brain injury using diffusion kurtosis imaging (DKI) in patients with severe diffuse axonal injury. MATERIAL AND METHODS: DKI data of 12 patients with severe DAI (11 patients with a Glasgow Coma Scale (GCS) score of ≤ 8 and 1 patient with a GCS score of 9) and 8 healthy volunteers (control group) were compared. MRI examination was performed 5 to 19 days after injury; 7 of the 12 patients underwent repeated MRI examinations. We assessed the following parameters: mean, axial, and radial kurtosis (MK, AK, RK, respectively) and kurtosis anisotropy (KA) of the white and gray matter; fractional anisotropy (FA), axonal water fraction (AWF), axial and radial extra-axonal diffusion (AxEAD and RadEAD, respectively), and tortuosity (TORT) of the extra-axonal space) of the white matter. Regions of interest (ROIs) were set bilaterally in the centrum semiovale, genu and splenium of the corpus callosum, anterior and posterior limbs of the internal capsule, putamen, thalamus, midbrain, and pons. RESULTS: A significant reduction in KA (p<0.05) in most of ROIs set on the white matter was revealed. AK was increased (p<0.05) not only in the white matter but also in the putamen and thalamus. A significant reduction in MK with time was observed when the first and second DKI data were compared. AWF was reduced in the centrum semiovale and peduncles. The TORT parameter was decreased (p<0.05) in the majority of ROIs in the white matter, with the most pronounced changes occurring in the genu and splenium of the corpus callosum. CONCLUSION: DKI provides novel data about microstructural injury in DAI and improves our knowledge of brain trauma pathophysiology. DKI parameters should be considered as potential biomarkers of brain injury and potential predictors of the outcome.

[Phosphorus (P) magnetic resonance spectroscopy for evaluation of brain tissue metabolism and measuring non-invasive pH. A study involving 23 volunteers. Part I]. / Fosfornaia (R) MR-spektroskopiia v otsenke énergeticheskogo metabolizma mozgovoi tkani i neinvazivnom izmerenii pH. Issledovanie 23 dobrovol'tsev. Chast' I.

Evaluation of brain metabolism is an important part in examination of brain lesions. Phosphorus magnetic resonance spectroscopy opens up great opportunities for studying the energy metabolism and allows noninvasive examination of metabolic processes occurring both in healthy and in pathologic brain tissue by obtaining a spectrum of phosphorus-containing metabolites involved in the turnover of cell membrane phospholipids. The technique presented in this paper was used to conduct 31P MR spectroscopy and to estimate the ratio between the peaks of the main metabolites and intracellular pH of the healthy brain tissue of 23 volunteers in the age group under 30 years old in clinical settings. Based on the recorded stable phosphorus spectra of metabolites of the healthy brain tissue, the value of intracellular pH (6.963±0.044) and the ratio of the main PME/PDE peaks (1.17±0.20) were calculated. The database was created to subsequently analyze the metabolic changes in brain tissue spectra in norm and in pathology, as well as the intracellular pH variations that have diagnostic and prognostic value.

[Evaluation of vascular reactivity to overcome limitations of neurovascular uncoupling in BOLD fMRI of malignant brain tumors]. / Otsenka vazoreaktivnosti dlia preodoleniia ogranichenii neirovaskuliarnogo razobshcheniia BOLD fMRT pri zlokachestvennykh opukholiakh golovnogo mozga.

The sensitivity of fMRI in identification of eloquent cortical centers in the case of large infiltrative growing tumors and pronounced peritumoral edema may be reduced or significantly limited in some cases. The main cause is an attenuated Blood-Oxygen-Level-Dependent response (BOLD) caused by pathological vascular reactivity and subsequent neurovascular uncoupling of fMRI. In our study, we attempted to overcome these limitations and increase the sensitivity of this technique in identification of eloquent cortical areas adjacent to brain tumors by using vasoreactivity features of a breath-holding test and including these data in the BOLD analysis. Local vasoreactivity using a breath-holding paradigm with the same block design of both motor and speech tests was determined in 5 healthy volunteers and 3 patients in the preoperative period (two patients with high grade gliomas and one patient with single metastasis). A coherence-based model was developed for analysis of BOLD fMRI, which took into account altered hemodynamics in peritumoral zones. Obtained coherence maps demonstrated clinically more significant activation zones that were not seen with standard methods of fMRI processing. Thus, neurovascular uncoupling that is known to affect the accuracy of the BOLD fMRI response adjacent to brain tumors may be partially overcome by including an independent measurement of vasoreactivity using a breath-holding test in the BOLD analysis.

[Orbital hemangiomas: capabilities of modern neuroradiological diagnostics]. / Gemangiomy orbity: vozmozhnosti sovremennoi neiroradiologicheskoi diagnostiki.

MATERIAL AND METHODS: In the period from 2010 to 2016. 14 patients with cavernous hemangioma (CH) and 2 patients with capillary hemangioma (CapH) of the orbit were examined. The age of CH patients varied from 17 to 67 years (median, 53 years); 8 females and 6 males. The age of CapH patients was 35 and 54 years. All patients underwent surgery with subsequent histological verification. CT-perfusion was performed in 10 CH patients and 2 CapH patients according to a developed low-dose protocol (80 kV, 200 mAs, tscan=40 s) with allowance for a target localizer (80 kV, 120 mAs) and at a maximum radiation dose of not more than 4.0 mZv. Neoplasm microcirculation was quantitatively assessed by calculating hemodynamic parameters: blood flow velocity (BFV), blood volume (BV), and mean transit time (MTT). MRI without and with contrast enhancement was performed in 11 CH patients and 2 CapH patients according to the ophthalmologic protocol (Signa GE, 3.0 T) accepted at the Institute: without contrast enhancement - T1, T2, and T2-FLAIR modes, T1 and T2 with a Fat Sat technique at a scan thickness of 3 mm, and DWI MRI; contrast enhancement - T1 (three projections) mode, including the Fat Sat technique. SWAN (n=2) and non-contrast MR perfusion ASL (n=3) were also used. Diffusion-weighted images (DWI) were processed with calculation of the apparent diffusion coefficient (ACD). RESULTS: In all CH patients, CT-perfusion revealed low perfusion parameters of blood flow: BVCH=0.86±0.37 mL/100 g, BFVCH= 4.89±2.01 mL/100 g/min with a high mean transit time MTTCH=10.13±3.05 s compared to the same parameters of blood flow in the normal white matter: CBVNormWM=1.63±2.22 mL/100 g, CBFVNormWM=9.72±3.13 mL/100 g/min, and MTTNormWM=6.76±2.78 s. In CapH cases, significantly increased blood flow velocity and volume values and a low MTT value in the tumor were observed: BVCapH=10.30±4.10 mL/100 g, BFVCapH=119.72±53.13 mL/100 g/min, and MTTCapH=4.35±1.79 s. In the case of orbital hemangiomas, optimal MRI modes were T1 and T2 with the Fat Sat technique, a scan thickness of 3 mm, and intravenous contrast enhancement. The revealed pattern of contrast agent accumulation by CH, initially in the central part and then in the periphery, may be a useful radiographic sign in the differential diagnosis with other orbital tumors. CONCLUSION: Modern CT- and MRI-based diagnostics of orbital hemangiomas provides not only the exact location, size, and spread of the lesion but also reveals the characteristic structural features of these tumors, and the use of perfusion techniques visualizes hemodynamics of the tumors. CT-perfusion-based hemodynamic parameters of cavernous hemangiomas typical of this type of hemangiomas may be used in the differential diagnosis with other tumors of this location. The use of contrast enhancement and the Fat Sat technique with a scan thickness of not more than 3 mm is optimal for MRI diagnostics of orbital hemangiomas.

[New opportunities of magnetic-resonance imaging: an algorithm of CSD-HARDI tractography in reconstruction of the brainstem reticular formation fibers]. / Novye vozmozhnosti magnitno-rezonansnoi tomografii: algoritm CSD-HARDI traktografii v postroenii volokon retikuliarnoi formatsii stvola.

The study purpose was to develop a technique for intravital visualization of the brainstem reticular formation fibers in healthy volunteers using magnetic resonance imaging (MRI). MATERIAL AND METHODS: The study included 21 subjects (13 males and 8 females) aged 21 to 62 years. The study was performed on a magnetic resonance imaging scanner with a magnetic field strength of 3 T in T1, T2, T2-FLAIR, DWI, and SWI modes. A CSD-HARDI algorithm was used to identify thin intersecting fibers of the reticular formatio. RESULTS: We developed a technique for reconstructing the reticular formation pathways, tested it in healthy volunteers, and obtained standard quantitative indicators (fractional anisotropy (FA), apparent diffusion coefficient (ACD), fiber length and density, and axial and radial diffusion). We performed a comparative analysis of these indicators in males and females. There was no difference between these groups and between indicators for the right and left brainstem. Our findings will enable comparative analysis of examination results in patients with brain pathology accompanied by brainstem injury, which may help predict the outcome. This work was supported by a grant of the Russian Foundation for Basic Research (#16-04-01472).

[Non-contrast ASL perfusion in preoperative diagnosis of supratentorial gliomas]. / Beskontrastnaia ASL-perfuziia v predoperatsionnoi diagnostike supratentorial'nykh gliom.

The purpose of this study was to investigate the potential of pseudocontinuous arterial spin labeling perfusion (pCASL) in assessing the degree of malignancy of brain gliomas at the preoperative stage. MATERIAL AND METHODS: The study included 126 patients aged 12-75 years with supratentorial gliomas of different malignancy (35 low-grade gliomas and 91 high-grade gliomas). The maximum tumor blood flow (TBF) was measured, and the normalized tumor blood flow (nTBF) was calculated relative to the intact semiovale white matter of the contralateral hemisphere. The TBF and nTBF indicators differed significantly between low-grade and high-grade glioma groups (p<0.001). When using TBF and nTBF in the differential diagnosis of low-grade and high-grade gliomas, the area under the ROC curve was 0.96 in both cases. Our findings suggest that 3D pCASL perfusion is an effective technique for preoperative differential diagnosis of low-grade and high-grade gliomas. The study was supported by the Russian Foundation for Basic Research (grant #18-315-00384).

[3D proton MR spectroscopy of the gray and white brain matter. A study of 15 volunteers]. / Protonnaia 3D MR-spektroskopiia serogo i belogo veshchestva golovnogo mozga. Issledovanie 15 dobrovol'tsev.

One of the important problems of modern diagnostics of brain diseases is detection of early lesions, which determines the choice of patient management and the disease outcome. The introduction of magnetic resonance imaging in practice has significantly improved the quality of diagnosis. Multivoxel proton magnetic resonance spectroscopy is an additional and clarifying technique enabling non-invasive examination of changes in brain metabolism in tumors as well as simultaneous acquisition of information on metabolism in surrounding tissues and in the intact brain matter. Along with single voxel MR spectroscopy (SV MRS) and 2D MRS (CSI Chemical Shift Imaging), 3D proton MRS (MRSI) has been increasingly used in clinical practice, which enables single-run acquisition of data on the metabolite composition for the entire volume of interest. OBJECTIVE: To assess the possibility of using multivoxel 3D proton MRS in healthy volunteers without organic brain pathology. MATERIAL AND METHODS: In this study, 15 volunteers without organic brain pathology were examined using the 3D 1H-MRS. CONCLUSION: 3D proton MRS has proven to be an effective technique in studying the brain metabolism. One short-term series of examinations provided information on intact brain metabolism at different anatomical levels, which enabled their comparison both in spectral data and in parametric maps of the major metabolite distribution.

[Phase contrast MRI-based evaluation of cerebrospinal fluid circulation parameters in patients with foramen magnum meningiomas]. / Otsenka parametrov likvorodinamiki u patsientov s meningiomami oblasti bol'shogo zatylochnogo otverstiya po dannym fazo-kontrastnoi MRT.

BACKGROUND: Meningiomas of the foramen magnum (FMR) region account for 1.8 to 3.2% of all meningiomas. The international literature has insufficient data describing the state of cerebrospinal fluid (CSF) circulation in these patients. MATERIAL AND METHODS: We studied 38 patients with FM meningiomas, aged from 35 to 79 years (mean age, 56.7 years). The mean meningioma size was 30 mm (10-60 mm). Meningiomas had the anterolateral localization in 29 patients, ventral localization in 5 patients, and dorsal localization in 4 patients. Twenty nine patients underwent surgery. All operated patients were examined before and after surgery. The CSF circulation was studied using phase contrast MRI (PC-MRI). RESULTS: The size and localization of FM meningiomas do not significantly affect the CFS circulation parameters. Pyramidal symptoms, sensory disorders, and XIth cranial nerve dysfunction are correlated with the CFS circulation parameters. According to the preoperative PC-MRI data, the CFS circulation parameters in all FM meningioma patients were significantly higher than their normal values. Surgery was followed by a reduction in the peak positive velocity, negative peak velocity, and range of the maximum linear velocity amplitude. Positive and negative volumes and the stroke volume did not change. Recovery dynamics of the CFS circulation parameters was similar, regardless of surgery completeness. According to the PC-MRI data, the CFS circulation parameters did not reach normal values in all groups of operated patients. CONCLUSION: The results of investigation of the CFS circulation in patients with FM meningiomas support the use of palliative surgery (partial resection, dural plasty, craniovertebral junction decompression) in the case of inoperable meningiomas.

[The structure of activation of the language zone in patients with intracerebral tumors according to fMRI with respect to tumor location and the functional asymmetry profile].

MATERIAL AND METHODS: A total of 50 patients were examined prior to surgical resection of intracranial tumors of the temporal and frontal lobes. Left-sided tumors were observed in 33 patients and right-sided tumors were observed in 17 patients. The functional asymmetry profile was determined using self-assessment, the Annet questionnaire, and the dichotic listening task. Twelve patients were left-handers or retrained left-handers and the remaining 38 patients were right-handers. FMRI examination was carried out on a 3.0 T SignaHDxt magnetic resonance tomograph (GE). The standard language block design paradigm was used in the study. We used the following tests: 1) recitation of months in reverse order; 2) generation of nouns according to the initial letters shown on the screen (K, M, L, N, P, C); 3) generation of verbs according to simple actions shown on the screen; 4) producing sentences using nouns shown on the screen; 5) listening to text through headphones. Data were processed using the standard BrainWave PA software (General Electric). Z-test was used in the range from 6 to 9. In all the studies, p<0.001. Statistical data processing included the nonparametric Spearman's test to determine the correlation between lateralization of the detected activation zone under speech load and tumor location (tumor is adjacent to the language zone, invades the language zone, or is located far from the language zone), as well as left- or right-handedness. RESULTS: Among 16 patients (right-handers and 2 left-handers) the activation of language zones was observed only on the left side; in one left-handed patient, Broca's area was detected only on the right side. In other patients (including right-handers with right-sided tumors), lateralization of language zones was different, including bilateral. Statistical processing revealed that bilateral activation of both Broca's and Wernicke's areas was more frequently observed in left-handers. Broca's area was more frequently detected on the left side in the presence of a distant tumor, while this trend did not apply for Wernicke's area. CONCLUSION: Localization of activation of Broca's area is more dependent on tumor location, while it depends on personal characteristics of an individual in the case of Wernicke's area.

[SCT perfusion in the diagnosis of sellar and parasellar tumors].

UNLABELLED: The study is devoted to the use of a minimally invasive method of SCT perfusion for the differential diagnosis of sellar and pаrаsellar tumors. Given a wide differential diagnostic range of tumors occurring in this area, the tumor perfusion indicators were used as an auxiliary diagnostic criterion. MATERIAL AND METHODS: The study analyzed outcomes in 115 patients with various tumors of the sellar area who underwent surgery or biopsy for histological verification of the diagnosis. RESULTS: The statistically significant differences were obtained for certain groups of tumors based on the values of hemodynamic parameters (p<0.05) that enable, with a high confidence, making a conclusion on the histologic type of most tumors. CONCLUSION: These findings demonstrated that SCT perfusion is a highly informative method of the preoperative differential diagnosis of these tumors. The sensitivity and specificity of SCT perfusion in the study were 100% and 81.2%, respectively.

[The analysis of fMRT answer's individual variability at healthy examinees when opening eyes, motor and speech tests].

This paper analyzes the variation of the functional anatomy of the brain in healthy people performing identical activities on the basis of functional magneticresonance imaging (fMRI). According to the authors, this approach allows you to showcase a variety of individual strategies to achieve the same external (behavioral) result intracerebral different means, and to identify the factors that determine this diversity. Investigated hemodynamic (fMRT) brain reactions at activization of attention to opening of eyes, motor (search of the right and left hand fingers) and speech tests (mental transfer of months or days of the week upside-down) at 21 healthy subjects (21-30 years): 14 men, 7 women. Certain variety of fMRT answers is revealed: 3-4 jet types of hemodynamic changes were allocated for test in group, and the percent of supervision of each type fluctuated from 40 to 10%. Shown marked gender differences responses which specificity is determined by the nature of the functional load. In motor and speech tests, performed with his eyes closed, fMRI response in women is characterized by greater specificity and locality than in men. At motor tests fMRT answers of men are accompanied big, than at women, inclusion in reaction of frontal areas of the cortex, providing realization of regulatory functions. When opening of eyes the women's fMRT responses, on the contrary, become more diffusion, and men's--more local.

[A correlation between diffusion kurtosis imaging and the proliferative activity of brain glioma].

UNLABELLED: The aim of the study was to assess the capabilities of diffusion kurtosis imaging (DKI) in diagnosis of the glioma proliferative activity and to evaluate a relationship between the glioma proliferative activity index and diffusion parameters of the contralateral normal appearing white matter (CNAWM). MATERIAL AND METHODS: The study included 47 patients with newly diagnosed brain gliomas (23 low grade, 13 grade III, and 11 grade IV gliomas). We determined a relationship between absolute and normalized parameters of the diffusion tensor (mean (MD), axial (AD), and radial (RD) diffusivities; fractional (FA) and relative (RA) anisotropies) and diffusion kurtosis (mean (MK), axial (AK), and radial (RK) kurtosis; kurtosis anisotropy (KA)) and the proliferative activity index in the most malignant glioma parts (p<0.05). We also established a relationship between the tensor and kurtosis parameters of CNAWM and the glioma proliferative activity index (p<0.05). RESULTS: The correlation between all the absolute and normalized diffusion parameters and the glioma proliferative activity index, except absolute and normalized FA and RA values, was found to be statistically significant (p<0.05). Kurtosis (MK, AK, and RK) and anisotropy (KA, FA, RA) values increased, and diffusivity (MD, AD, RD) values decreased as the glioma proliferative activity index increased. A strong correlation between the proliferative activity index and absolute RK (r=0,71; p=0.000001) and normalized values of MK (r=0.8; p=0.000001), AK (r=0.71; p=0.000001), RK (r=0.81; p=0.000001), and RD (r=-0.71; p=0.000001) was found. A weak, but statistically significant correlation between the glioma proliferative activity index and diffusion values RK (r=-0.36; p=0.014), KA (r=-0.39; p=0.007), RD (r=0.35; p=0.017), FA (r=-0.42; p=0.003), and RA (r=-0.41; p=0.004) of CNAWM was found. CONCLUSION: DKI has good capabilities to detect immunohistochemical changes in gliomas. DKI demonstrated a high sensitivity in detection of microstructural changes in the contralateral normal appearing white matter in patients with brain gliomas.

[Structural and functional peculiarity of brain activity to performance and imaginary motor tasks in healthy persons (EEG and fMRI study)].

Bioelectrical (EEG) and hemodynamic (fMRI-response) cerebral reactions to performance and imaginary motor tasks by right or left hand were analyzed in 15 right-handed healthy persons (21-39 years old). During actual movement the main fMRI-response was registered in the area of central gyrus of the hemisphere contralateral to the working hand. Areas of activation were also revealed in the supplemental motor area and the ipsilateral hemisphere of the cerebellum. EEG data showed coherence increase in high frequency alpha- and beta-bands in the activated hemisphere. In imaginary motor tasks the intensity and topography of fMRI-response became the more variable; response was decreased in the motor area and in cerebellum, they increased in the subcortical structures and in the parietal association zones. EEG changes were very variable in this situation also; it was observe an increase of EEG coherence in the right hemisphere for higher frequency of alpha and beta spectral bands. Changes of power spectrum parameters were similar to performance and imaginary motor tasks. Spectrum power and middle frequency of beta band were increased. Topographically these changes did not correspond to activated hemisphere and it was more in the left hemisphere. These changes were reflected nonspecific component of reaction.

[fMRI study of the dominant hemisphere for language in patients with brain tumor].

THE AIM OF THE STUDY: Paper describes a study of language lateralization of patients with brain tumors, measured by preoperative functional magnetic resonance imaging (fMRI) and comparison results with tumor histology and profile of functional asymmetry. METHODS: During the study 21 patient underwent fMRI scan. 15 patients had a tumor in the left and 6 in the right hemisphere. Tumors were localized mainly in the frontal, temporal and fronto-temporal regions. Histological diagnosis in 8 cases was malignant Grade IV, in 13 cases--Grade I-III. fMRI study was perfomed on scanner "Signa Exite" with a field strength of 1.5 As speech test reciting the months of the year in reverse order was used. fMRI scan results were compared with the profile of functional asymmetry, which was received with the results of questionnaire Annette and dichotic listening test. RESULTS: Broca's area was found in 7 cases in the left hemisphere, 6 had a tumor Grade I-III. And one patient with glioblastoma had a tumor of the right hemisphere. Broca's area in the right hemisphere was found in 3 patients (2 patients with left sided tumor, and one with right-sided tumor). One patient with left-sided tumor had mild motor aphasia. Bilateral activation in both hemispheres of the brain was observed in 6 patients. All of them had tumor Grade II-III of the left hemisphere. Signs of left-handedness were revealed only in half of these patients. Broca's area was not found in 4 cases. All of them had large malignant tumors Grade IV. One patient couldn't handle program of the research. CONCLUSIONS: Results of fMRI scans, questionnaire Annette and dichotic listening test frequently were not the same, which is significant. Bilateral activation in speech-loads may be a reflection of brain plasticity in cases of long-growing tumors. Thus it's important to consider the full range of clinical data in studying the problem of the dominant hemisphere for language.

[Prognostic value of ICP, CPP and regional blood flow monitoring in diffuse and focal traumatic cerebral lesions].

Forty patients with severe traumatic brain injury (GCS score 8 and less) aged 16-54 years treated in our clinic were analyzed. Correlations between clinical symptoms, CT signs of diffuse and focal traumatic lesions, intracranial hemorrhage, indices of cerebral blood flow (CBF) according to perfusion CT study, intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were assessed. Main mechanism of injury in 27 of 40 (67.5%) patients was acceleration-deceleration due to traffic accidents which usually leads to diffuse axonal injury (DAI) of different severity. In the other 13 (32.5%) cases injury was associated with coup-countercoup mechanism which caused focal contusions mostly. Not only GCS score but CT-signs of DAI severity, intracranial hemorrhage and minimal levels of CPP had significant prognostic value. Results of perfusion CT studies demonstrated that in 37 of 40 (92.5%) patients cerebral blood flow decreased (below 28.6 ml/100 g/min) in one or more arterial blood distribution areas. Increase of CBF was registered in 9 cases (over 69 ml/100 g/min), in 6 of them elevation of CBF in one arterial distribution area was associated with reduction in the other. Generally, mean CBF values were higher in the middle cerebral artery circulation than in the other. The lowest CBF levels (16.3 +/- 6 ml/100 g/min) were observed in cortical and subcortical hemorrhagic foci while these values were significantly higher in the same contralateral intact zones (36.0 +/- 10.0 ml/100 g/min; p < 0.01). In 3 patients with DAI the CBF in the midbrain varied from 12.5 to 30.1 ml/100 g/min with the lowest levels in hemorrhagic focus in cerebral peduncle. It corresponded to cystic-atrophic alterations found on subsequent follow-up MRI. Thus, reduction of CBF and episodes of low CPP were the leading pathophysiological phenomena of diffuse and focal brain damages.