Mutations of isocitrate dehydrogenase (IDH) have important prognostic significance for patients with glial brain tumor. The method of proton MR spectroscopy makes it possible to non-invasively determine the metabolic properties of the tumor tissue at the preoperative stage. The aim of this work was to study the possibility of determining the IDH status, by using magnetic resonance spectroscopy (MRS) to detect the 2-hydroxyglutarate (2HG), a metabolic product of the IDH enzyme. We examined 33 patients with glial tumors varying degrees of malignancy (Gr. 2–4), followed by identification of IDH mutations. IDH mutation identified in 20 cases, according to proton magnetic resonance spectroscopy, was confirmed by immunohistochemistry. Peak of 2HG did not detect in 13 cases on the MR spectrum, and the analysis for IDH did not reveal mutations. Using of proton magnetic resonance spectroscopy showed a high sensitivity of this technique in predicting the mutational status of glial brain tumors, which makes this method an important in preoperative diagnostics.

Background: Metastatic brain lesions lead to the most unfavorable prognosis for the course of an oncological disease. Most often, brain metastases arise from primary tumors such as lung cancer, breast cancer, and melanoma. Of particular interest are groups of secondary intracranial tumors without an identified primary focus. Methods of non-invasive differential diagnosis based on a possible histological affiliation, including diffusion-kurtosis magnetic resonance imaging, can improve the diagnostic search for the primary tumor. Aim: The aim of this study is to improve the quality of differential diagnosis for brain metastases of tumors of different primary localization by introducing the diffusion-kurtosis magnetic resonance imaging technique into the magnetic resonance scanning protocol. Methods: Our work included studies of 60 patients who underwent examination and treatment at the N.N. Blokhin National Research Medical Center of Oncology of the Ministry of Health of Russia from October 2019 to March 2022. According to magnetic resonance imaging, metastatic formations were detected in the brain of the patients, with different localizations of the primary tumor. 20 patients were diagnosed with lung cancer (33.3%), 20 patients with breast cancer (33.3%) and 20 patients with melanomas (33.3%). We evaluated the tumor size, diffusion and kurtosis parameters, such as the mean kurtosis, axial kurtosis, radial kurtosis, kurtosis anisotropy, radial diffusion, and fractional anisotropy, and relative anisotropy, axial diffusion of the extra-axonal fluid, radial diffusion of the extra-axonal fluid, axonal fluid fraction, and tortuosity of the diffusion trajectory. Results: Statistically significantly (p 0.05) differing parameters of diffusion and kurtosis in the comparative evaluation of the above indicators were identified in the structure associated with melanoma and lung cancer axial diffusion, fractional anisotropy, relative anisotropy, radial kurtosis and tortuosity of the diffusion trajectory, as well as in the structure of melanoma and breast cancer — axial diffusion, axonal fluid fraction, fractional anisotropy, axial diffusion of extra-axonal fluid, mean kurtosis, relative anisotropy, radial kurtosis and tortuosity of the diffusion trajectory. Conclusion: Diffusion-kurtosis magnetic resonance imaging is a promising technique that allows obtaining additional differential information in the case of metastatic lesions of the brain matter, especially those from an undetected primary focus.

OBJECTIVE:Assessing the diagnostic significance of MR morphometry in determining the localization of focal cortical dysplasias (FCD).MATERIAL AND METHODS:The study included 13 children after surgery for drug-resistant epilepsy caused by FCD type II and stable postoperative remission of seizures (Engel class IA, median follow-up 56 months). We analyzed the results of independent expert assessment of native MR data by three radiologists (HARNESS protocol) and MR morphometry data regarding accuracy of FCD localization. We considered 2 indicators, i.e. local cortical thickening and gray-white matter blurring.RESULTS:FCD detection rate was higher after MR morphometry compared to visual analysis of native MR data using the HARNESS protocol. MR morphometry also makes it possible to more often identify gray-white matter blurring as a sign often missed by radiologists (p<0.05).CONCLUSION:MR morphometry is an additional non-invasive method for assessing the localization of FCD.

Mutations of isocitrate dehydrogenase (IDH) have important prognostic significance for patients with glial brain tumor. The method of proton MR spectroscopy makes it possible to non-invasively determine the metabolic properties of the tumor tissue at the preoperative stage. The aim of this work was to study the possibility of determining the IDH status, by using magnetic resonance spectroscopy (MRS) to detect the 2-hydroxyglutarate (2HG), a metabolic product of the IDH enzyme. We examined 33 patients with glial tumors varying degrees of malignancy (Gr. 2-4), followed by identification of IDH mutations. IDH mutation identified in 20 cases, according to proton magnetic resonance spectroscopy, was confirmed by immunohistochemistry. Peak of 2HG did not detect in 13 cases on the MR spectrum, and the analysis for IDH did not reveal mutations. Using of proton magnetic resonance spectroscopy showed a high sensitivity of this technique in predicting the mutational status of glial brain tumors, which makes this method an important in preoperative diagnostics.

Motor disorders are among the most common consequences of severe craniocerebral injury (traumatic brain injury — TBI). Deeper insights into pathophysiological mechanisms of these disorders is important both from a theoretical point of view and in terms of improving neurorehabilitation approaches.The aim of the study was to investigate the correlation of right–sided posttraumatic hemiparesis severity with composite characteristics of fractional anisotropy (FA) in the segments of the corpus callosum (CC), corticospinal tract (CST) and the inferior fronto-occipital fasciculus (IFO) at different stages of traumatic disease (acute, subacute and long-term periods).Material and methods. Cases of 43 patients with TBI were analyzed (28 men and 15 women aged 13 to 59 years, mean age 28±9 years). Forty patients were diagnosed with severe TBI with diffuse axonal damage, three patients had moderate severity TBI. Long-term follow up included continuous clinical and neurological examination with evaluation of patient’s level of consciousness using the CRS-R scale, and the degree of motor deficits in right-sided hemiparesis using a five-point scale. During three post-TBI periods (up to 1 month, from 1 to 6 months, and from 6 to 12 months), patients were examined using diffusion tensor MRI (DTI), tractography and FA. Motor, cortico-spinal tracts and IFO were divided by measurement grid, correlations between FA and scores of right-sided hemiparesis were calculated for each segment.Results. FA correlations (P0.05) with the severity of hemiparesis were established not only for CST motor-specific segments, but also for some CC and IFO segments. In the early period of TBI significant correlations with hemiparesis severity were found not only in the contralateral CST segments, but also in the ipsilateral ones. Significant differences in FA in the related CC and CST segments were found between the groups with good and limited motor recovery: at all stages after TBI, FA was higher in patients with successful recovery.Conclusion. The results of the study provide better insight into pathophysiological mechanisms of post-traumatic motor disorders development, therefore favoring optimization of therapeutic strategies.

Aim: to present a new method for assessing glucose catabolism in brain tissues of healthy volunteers and neurooncology patients. This method is MR spectroscopy with resonance frequency of deuterium (hydrogen isotope) called deuterium metabolic imaging - DMI. Material and methods. We searched scientific papers in PubMed and Google Scholar indexing systems for 2017–2022 publicatioin years. Keywords used: deuterium spectroscopy, DMI, DMV, PET, non-proton spectroscopy, brain tumor metabolism, Warburg effect in brain tumor, glucose/glucolytic flux/metabolism. Results. 474 articles were analyzed, 21 of which were used for this review. The references list additionaly includes 9 articles for 1924–2014 pyublication years. The review covers the history of proton and multinuclear MR spectroscopy (phosphorus, carbon, deuterium) development of and PET diagnostics. We described DMI applicability in visual and quantitative assessment of tissue metabolism disorders in brain tumors and discussed its future use in clinical practice. Conclusion. Compared to fluorodeoxyglucose (FDG) PET, the DMI method provides additional information on metabolic disorders during anaerobic glycolysis in a tumor. DMI can be implemented and performed on clinical MRI scanners.

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.

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.

Purpose : To improve the differential diagnosis of high-grade gliomas and solitary metastases by introducing the diffusion-kurtosis magnetic resonance imaging technique into the MRI scan protocol. Material and methods : The study included 43 patients who underwent examination and treatment at the N.N. Blokhin National Research Medical Center of Oncology from October 2019 to March 2022, in which, according to magnetic resonance imaging, solitary formations in the brain substance were detected. A total of 43 neoplasms were found in the substance of the brain, of which: 17 glioblastomas in 17 patients (40 %), 25 solitary metastatic tumors of lung, breast, melanoma and kidney cancer (60 %). We evaluated the tumor size, diffusion and kurtosis parameters, such as mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), kurtosis anisotropy (KA), radial diffusion (RD), fractional anisotropy (FA), relative anisotropy (RA), tortuosity of the trajectory (TTD). Results : Statistically significant differences (р < 0.05) in such parameters of diffusion and kurtosis in the tumor as kurtosis anisotropy (KA), fractional anisotropy (FA) and tortuosity of the trajectory (TT) were revealed. Significant differences between solitary metastases and malignant glial tumors based on diffusion and kurtosis values such as mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), radial diffusion (RD), and relative anisotropy (RA) (criteria where р > 0.05) was not detected.

This review provides insight into application of modern MRI modalities including diffusion kurtosis imaging in assessment of perifocal glioma zone. Differentiation of “pure” perifocal vasogenic edema from edema infiltrated by glioma cells, as well as identification of peritumoral intact (on conventional MRI) brain matter infiltration make it possible to determine glial tumor borders more accurately. Analysis of diffusion and perfusion quantitative MR data allow determining glioma borders in areas with unaltered blood-brain barrier. There is a growing possibility to develop a personalized navigation algorithm for surgical removal of the tumor, followed by the determination of an individual plan for radiation and chemotherapy, as well as prediction of disease outcomes.

The aim of this work is to evaluate the universality of non-contrast MR perfusion (PCASL) in determining the rate of cerebral blood flow (CBF) of brain gliomas using magnetic resonance scanners with different magnetic field strengths. The maximum and normalized CBF values, which received on 1.5 and 3.0 T MRI in the same patients with histologically verified high grade gliomas (III, IV grade), were compared with each other. The data obtained by us are reliably comparable, which allows us to consider pCASL as a universal technique for scanners with different magnetic strengths.

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.

Magnetic resonance imaging (MRI) is presently one of the main methods in the diagnosis of diseases associated with impaired fluid dynamics. Rapidly developing MRI technologies allow us to get more and more information about the functional organization of both individual components and the entire cerebrospinal fluid system (CSF) as a whole. One of the most common diseases accompanied by impaired CSF flow, where the superiority of MRI among other non-invasive methods is especially obvious, is hydrocephalus. The review considers the current capabilities of MRI in assessing CSF flow in various forms of hydrocephalus.

The purpose of the study — to create an original algorithm of MR-morphometry for identifying FCD zones. Based on the use of the ANTs and FSL programs, an algorithm for MR morphometry was developed. It was used to generate maps of the z-index of the blur of the transition of gray and white matter and the thickness of the crust (Junction and thickness maps).An algorithm for automatic detection of focal cortical dysplasia zones has been developed. The MRI morphometry method is a promising technique for additional assessment of pathological changes in focal cortical dysplasia.

МУЛЬТИВОКСЕЛЬНАЯ 3D МАГНИТНО-РЕЗОНАНСНАЯ СПЕКТРОСКОПИЯ И ПОЗИТРОННО-ЭМИССИОННАЯ ТОМОГРАФИЯ С 11

Introduction . Preoperative fMRI often shows a reduced BOLD response in the areas located perifocal to brain tumors caused by pathological vasoreactivity as a result of neurovascular uncoupling. The aim of this study was an accurate identification of the eloquent cortical areas near brain tumors by measuring vasoreactivity using the breath holding test. Material and methods. 23 patients with brain tumors located near eloquent cortical areas underwent fMRI mapping of the language and / or motor cortical areas depending on the location of the tumor. Breath hold test was also included, the design of which coincided with motor and language block paradigms. Results . A statistical dependency between motor, speech tasks and breath-hold BOLD-response was included into the BOLD analysis using coherence. fMRI activation maps generated by this method showed activation in the eloquent areas adjacent to brain tumors which were not detected by the standard analysis. This study shows that neurovascular uncoupling affects the accuracy of BOLD fMRI in brain tumors. Conclusion. The results of fMRI mapping can be partially improved by the incorporating vasoreactivity measurements into a standard analysis.

According to the literature, fMRI analysis at resting state (RS) is an informative methodological approach to the study of the basic level of a healthy and diseased brain’s functional activity. Averaging data over observation groups for various forms of cerebral pathology is often unacceptable. Previously, we mastered and applied the Independent Component Algorithm (ICA) in FSL software to visualize and analyze individual fMRI resting networks of healthy people. Objective : to analyze individual fMRI resting networks associated with the state of motor activity and consciousness in patients with severe traumatic brain injury (STBI). Materials and methods . Observation groups: 23 patients with SТBI (main) and 17 healthy volunteers (control). 3T fMRI recorded at rest. Individual (norm and STBI) and group (norm) analysis of RS networks was carried out by FSL software (ICA algorithm) and SPM8 in MATLAB. For the DMN and Sensorimotor networks, topography and total volume and intensity of their activation of their activation were determined. Results. The topography features reproduced in the group and individual analysis of fMRI of healthy people, as well as the averaged quantitative indicators of the rest networks were used as reference for pathology. In the context of motor activity, the RS Sensorimotor network was considered. Its topography is close to normal in most patients without or with mild hemiparesis. The growth of this defect is accompanied by a decrease in the integral quantitative indicators of the network, combined with asymmetric reduction (lack of activation in the contralateral motor cortex) in rough hemiparesis. In the context of consciousness, the expression and characteristics of the DMN network were compared in healthy people and in patients with STBI at its various levels: from clear to chronic vegetative state. It was revealed that a decrease in the level of consciousness is accompanied by a reduction in the cortical components of DMN, primarily the frontal (anterior DMN), not pronounced in the vegetative state. Activation of the caudal component of DMN (in particular, the posterior cingular cortex) persists in patients with depressed consciousness: distinct and even somewhat enhanced compared to the norm with its reversible form, less pronounced with chronic Conclusion . The data obtained indicate the informative value of fMRI analysis of individual resting networks in the context of studying cerebral structural and functional foundations of consciousness and motor activity, as well as diagnosing the state of these functions in STBI.

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.

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).

Analysis of fMRI in the resting state (RS) is a suitable methodological approach to studying basal levels of functional brain activity in humans in health and disease. The inadequate development of this direction in Russia is partly due to the small number of Russian publications describing approaches to data processing. This study uses an algorithm for analysis of fMRI signals in the RS based on independent components analysis (ICA) run in the FSL environment and used for studies of typical functional resting state networks (RSN) in health. Averaging observation data by group, which is applicable for studies of healthy people, is often not appropriate for studies of different forms of cerebral pathology, which are characterized by significantly greater levels of variation in hemodynamics. Thus, studies of 17 healthy subjects included comparative evaluation of the topography and a number of quantitative measures of typical RSN identified by group and individual analysis of fMRI signals. These networks were comparable with RSN described in the literature as main and were also reproducible in group and individual analysis, which confirms the suitability, reliability, and effectiveness of using this algorithm. Individual analysis of RSN identified variability linked with a number of psychophysiological characteristics of healthy subjects (sex, motor asymmetry profile, EEG pattern), partly explaining the different levels of compliance with the patterns of the group networks. Results obtained from individual fMRI and EEG comparisons showed the potential of analysis of the topography of the sources of individual rhythms as EEG markers for RSN. The lowest levels of variability of fMRI characteristics of resting networks in health (such as maximum network activation intensity, mean frequency of the active zone of the spectrum, frequency of dominant peak) may have diagnostic value for studies of RSN in pathology.