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Additional suppression of the background signal in diffusion-weighted images (DWIBS) allows to get more contrast images to highlight areas with restricted diffusion, for example, in many malignant primary and metastatic tumors. Due to fundamental differences in DWIBS and DWI acquisition, the apparent diffusion coefficient (ADC) values may differ, which could negatively affect attempts to compare with the available literature data or with conventional DWI studies. Purpose. Evaluation of the correctness of the calculation of the ADC values based on DWIBS images, compared to regular DWI. Material and methods. A comparative analysis of the ADC values obtained using DWIBS and conventional DWI on an MR-compatible phantom and on 20 healthy volunteers was carried out. Free breathing DWIBS as well as DWI with breath synchronization were acquired using 1.5 T MRI scanner. Results and discussion. ADC values measured with DWIBS and DWI were found to coincides well both for the phantom and for the volunteers in all the areas (vertebra, kidney, spleen), except for the liver, where the ADC values obtained from DWIBS images were 11 % lower than with standard DWI (1.06 vs 0.92 mm2/s). This may be due to the greater displacement of the liver during respiratory movements. The advantages of the DWIBS technique include a significant decrease in scan time (1.5-2 times with a 10 % decrease in signal-to-noise ratio compared to routine DWI), which allows for a quantitative analysis of ADC values in a whole-body scan in a comfortable timing for the patient. Conclusion. DWIBS can be recommended for calculating ADC values, however, a comparative analysis of ADC values in organs and tissues exposed to strong respiratory movements require additional assessments of repeatability and reproducibility directly when comparing areas with a strongly pronounced diffusion restriction.

Introduction. In MRI, the difference in sensitivity between tissues is used to obtain images weighted by the inhomogeneity of the magnetic field termed susceptibility-weighted imaging (SWI) and a high-resolution 3D radiofrequency gradient echo scan with full speed compensation is applied. The aim was to determine the features of lesions caused by traumatic brain injury in children using the SWI sequence. Materials and methods. 535 TBI children aged two months up to 18 years old (average age 9.58 ± 1.5) were studied. There were 325 boys (60.7%), 210 girls (39.3%). MRI was performed without and with intravenous contrast on a Phillips Achieva 3 T scanner with T1- and T2WI, 2D and 3D images, FLAIR, magnetic resonance angiography (TOF MRA), SWI, and DW/DTI, MRS and fMRI, SWI were used for visualization of DAI. Results. Patients included children with severe TBI - 178 (33.3%), moderate TBI - 172 (32.1%) and mild TBI - 185 (34.6%). Of the 535 injured children, 129 (24.1%) had MRI performed within the first 24 hours from the moment of injury, up to 48 hours - at 91 (17.0%), up to 72 hours - in 78 (14.6%) and up to 13 days - in 237 (44.3%). DAI foci at all degrees of TBI were detected in 422 (78.9%) children out of 535 children. Conclusion. SWI is a sensitive method for diagnosing brain lesions in TBI and significantly contributes to predicting outcomes in the early stages after trauma. The amount of brain lesions diagnosed by SWI correlates with the degree of injury according to the Glasgo Coma Scale. The study of the brain functional connections can inform about possible relationships between the localization of the SWI lesion and cognitive deficits, potentially providing an opportunity to use SWI in the hyperacute phase.

Mild traumatic brain injury (mTBI) is the most common neurological damage in children that's why it is extremely important to identify and analyze biomarkers that can help in predicting patient's treatment and recovery in period of mTBI. Aim of this study is to verify a hypothesis that functional connectivity disturbances between intact cerebellum and DMN nodes are included in symptomatic manifestation of mTBI.Methods. 28 MR negative patients with mTBI were studied in age from 12 to 17 years (mean age – 14.7 years). The control group consisted of 23 healthy children. All MRI studies wereperformed on a Philips AchievadStream 3.0 T scanner equipped with a 32-channelPhilips dStream head coil. A 4 min rsfMRI gradient-echo echo planar imaging (EPI)sequence was acquired (TR = 3000 ms, echo time (TE) = 30 ms, 80 dynamics withdynamic scan time = 3 s). fMRI data were processed using functional connectivitytoolbox CONN.Results. No statistically significant differences in correlation strengths between control group and group of patients were detected as a result of DMN analysis. Intergroup seed-basedcorrelation ROI analysis revealed statistically significant (p < 0.05) differencein links between DMN regions and vermis (cerebellum): positive link in control group and negative link in groupof patients.Conclusions. The revealed changes in DMN neuronal connection and cerebellar regions in acute stage of mTBI patients can be an initial step of damages leading to cognitive deficit which can be developed in future.

Purpose To separately measure N-acetyl aspartul glutamate (NAAG), N-acetyl aspartate (NAA), aspartate (Asp), and glutamate (Glu) concentrations in white matter (WM) using J-editing techniques in patients with mild traumatic brain injury (mTBI) in the acute phase. Methods Twenty-four patients with closed concussive head injury and 29 healthy volunteers were enrolled in the current study. For extended 1 H MRS examination, patients and controls were equally divided into two subgroups. In subgroup 1 (12 patients/15 controls), NAAG and NAA concentrations were measured in WM separately with MEGA-PRESS (echo time/repetition time [TE/TR] = 140/2000 ms; δ ON NAA / δ OFF NAA = 4.84/4.38 ppm, δ ON NAAG / δ OFF NAAG = 4.61/4.15 ppm). In subgroup 2 (12 patients/14 controls), Asp and Glu concentrations were acquired with MEGA-PRESS (TE/TR = 90/2000 ms; δ ON Asp / δ OFF Asp = 3.89/5.21 ppm) and TE-averaged PRESS (TE from 35 ms to 185 ms with 2.5-ms increments; TR = 2000 ms) pulse sequences, respectively. Results tNAA and NAAG concentrations were found to be reduced, while NAA concentrations were unchanged, after mild mTBI. Reduced Asp and elevated myo-inositol (mI) concentrations were also found. Conclusion The main finding of the study is that the tNAA signal reduction in WM after mTBI is associated with a decrease in the NAAG concentration rather than a decrease in the NAA concentration, as was thought previously. This finding highlights the importance of separating these signals, at least for WM studies, to avoid misinterpretation of the results. NAAG plays an important role in selectively activating mGluR3 receptors, thus providing neuroprotective and neuroreparative functions immediately after mTBI. NAAG shows potential for the development of new therapeutic strategies for patients with injuries of varying severity.

Wide-spread visualization methods which are computed tomography (CT) and magnetic resonance imaging (MRI) are not sensitive to mild traumatic brain injury (mTBI). However, mTBI may cause changes of cerebral microstructure that could be found using diffusion-tensor imaging. The aim of this study is to reveal the impact of acute mTBI (no more than 3 days after trauma) on diffusion parameters in corpus callosum, corticospinal tract, and thalamus in children (aged 14–18). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were analyzed. Significant increase in FA and decrease in ADC were observed in thalamus. The trend to an increase in FA is observed in corpus callosum.

—Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain; it plays an important role in various types of synaptic plasticity and pathology. In the present work, proton magnetic resonance spectroscopy (1H-MRS) and two modified MEGA-PRESS pulse sequences, that is, –GABAMEGA-PRESS and +GABAMEGA-PRESS, were used to investigate the effect of visual stimulation on the GABA level in the human visual cortex in vivo. With –GABAMEGA-PRESS, it was possible to acquire the 1H-NMR signal of methylated protons of GABA with the chemical shift δ = 3.01 ppm without the signals from macromolecules. When +GABAMEGA-PRESS was used, the GABA signal was a superposition of resonances of methylene protons of GABA and macromolecules. The effect of constant visual stimulation on the level of N-acetylaspartate and total level of glutamate and glutamine was also estimated. Constant visual stimulation had no effect on the levels of N-acetylaspartate and glutamine in the visual cortex. The –GABA signal intensity decreased with a statistically significant decrease in the level of GABA signal intensity leading to inactivation of GABA synthesis. No statistically significant changes in the intensity of the +GABA resonance were found, probably due to the effect of visual stimulation on macromolecules. In order to test this hypothesis, a signal from macromolecules was acquired using a specifically designed inversion-recovery pulse sequence. It was shown that the intensity of this signal is unaffected by visual stimulation and the absence of changes in the intensity of the +GABA signal during the stimulation has to be considered as the masking effect of macromolecular signal.

Previously using 31P magnetic resonance spectroscopy (MRS) we have demonstrated that one hyperbaric oxygenation (HBO) session (with O2 pressure 1.2 atm) directly activates cerebral energetics: the decrease in creatine phosphate (PCr) and, possibly, the increase in nicotinamide adenine dinucleotide. The aim of this study is to elucidate the effect of one HBO session on the concentrations of metabolites detectible by 1H MRS, and on the connectivity in Default Mode Network. Absolute concentrations of the metabolites were calculated. The reduction of N-acetyl aspartate by 3% was found in mediolateral prefrontal cortex (MPFC) with p

Intracellular concentrations of N acetyaspartate (NAA), aspartate (Asp) and glutamate (Glu) were determined for the first time in human brain in vivo, and the effect of severe traumatic brain injury on NAA synthesis in acute and late post-traumatic period was investigated. In MRI‑negative frontal lobes one day after injury Asp and Glu levels were found to decrease by 45 and 35%, respectively, while NAA level decreased by only 16%. A negative correlation between NAA concentration and the ratio of Asp/Glu concentrations was found. In the long-term period, Glu level returned to normal, Asp level remained below normal by 60%, NAA level was reduced by 65% relative to normal, and Asp/Glu ratio significantly decreased. The obtained results revealed leading role of the neuronal aspartate-malate shuttle in violation of NAA synthesis.

For the first time the intracellular concentrations of N-acetylaspartate (NAA), aspartate (Asp), and glutamate (Glu) were measured in human brain in vivo, and the effect of severe traumatic brain injury on NAA synthesis in acute and remote posttraumatic phases was revealed. In non-damaged (MRI-negative) lobes the next day after injury, Asp and Glu decreased by 45% and 35%, respectively, while NAA decreased only by 16%. A negative correlation between NAA and Asp/Glu ratio was found. The Glu level returned to the norm long after injury, Asp remained below the norm by 60%, NAA decreased by 65% relative to the norm, and Asp/Glu decreased significantly. The results obtained educe the leading role of neuronal aspartate-malate shuttle in NAA synthesis alterations.

Multi-sliced computed tomography (MSCT) is widely used to study patients with polytrauma, especially when assessing skeletal and spinal injuries as it has provided possible volume visualization. MSCT has long been used to diagnose injuries of pelvic bones and the spine. For the examination of limb injuries, it is used rarely until now. Although traditionally used radiography often underestimates degree and severity of damages, especially in the complex body parts such as shoulder, elbow, wrist, knee and ankle joints. The role of MSCT is extremely important to identify complex and small fractures, their nature and evaluation, planning of treatment. Multiplanar reconstruction clearly visualizes structural features, and three-dimensional images help to understand spatial relationships, which is important for pre-operative planning and classification of fractures. In addition, modern technologies for suppressing metal artifacts in MSCT allow monitoring postoperative results even in the presence of metal implants.

Cerebral concentrations of N-acetylaspartate, aspartate, and glutamate were determined for the first time simultaneously in patients with severe traumatic brain injury in the remote period using J-modulated editing of 1H magnetic resonance spectra in vivo. It has been shown that the N-acetylaspartate and aspartate concentrations in the frontal lobes of the brain were significantly reduced (by 65 and 61%, respectively) with a constant concentration of glutamate in the remote period after severe brain injury. Our findings indicate that a decrease in the N-acetylaspartate concentration in the delayed period after brain injury is caused by a decrease in the concentration of aspartate, a precursor of the synthesis of N-acetylaspartate. The decrease in the aspartate level with a constant level of glutamate is a consequence of the dysfunction of one of the most important metabolism regulation systems, namely, the malate–aspartate shuttle.

For the first time, the effects of one hyperbaric oxygenation (HBO) session on cellular phosphate metabolite levels and pH were investigated in vivo. 31P magnetic resonance spectroscopy was used in this study. The optimized protocol of Image-Selected Invivo Spectroscopy pulse sequence for 31P MRS was applied to increase SNR of ATP resonances. An activation of energy metabolism that manifested in the decrease of creatine phosphate and pHint after an HBO session is revealed. The growth of the α-ATP signal is elucidated as well, while other ATP resonances remain unchanged. This might reflect the increase in nicotinamide adenine dinucleotide (NAD) concentration. The rise of its level as well as the detected creatine phosphate expenses immediately after HBO may denote the activation of fast NAD synthesis pathways.

A procedure was developed for the first time for simultaneous in vivo quantification of local aspartate and glutamate concentrations in the human brain using 1H magnetic resonance spectroscopy (1H MRS) and spectral J-editing. The MEGA-PRESS pulse sequence was modified to observe β-CH2 nonequivalent proton resonances of aspartate (δ 2.65 and 2.80) and glutamate (δ 2.04 and 2.12) overlapped by signals of other metabolites. The frequencies, frequency selective pulse durations, and optimal echo times were selected by simulation and experimentally (for phantoms and in the brain in vivo).

Blunt abdominal trauma is one of the leading causes of the morbidity and mortality in all age groups. Among all the causes of deaths due to injury, abdominal damage accounted of about 10%, and in children - 8.5%. Timely imaging takes a key place in assessing abdominal injury in traumatized children. Computer tomography (CT) is a method of visualization that allows recognize and evaluate characteristic signs of the traumatic damage in hemodynamically stable children. Modern multislice spiral computer tomographs (MSCT) provide high quality of the image due to the improvement of both scanning methods and post-processing facilities. Currently, CT allows most accurately detect lesions of parenchymal and hollow organs, as well as reveal and quantify intraperitoneal and extraperitoneal fluid and blood. In addition, CT has an exceptional sensitivity in the diagnosis of the combined trauma of various organs and systems. The use of CT as the main screening method for the examination of traumatized children along with the improvement of maintenance therapy plays a crucial role in the success of the not operative treatment of trauma to parenchymatous organs. The rapid assessment of the state of traumatized children according to CT findings also contributed to the decline of the incidence of complications and mortality rate. The decision about surgical intervention in a small number of children in need of surgical treatment is primarily made on the basis of clinical criteria, not CT results. Thus, CT mainly determines non-operative decisions regarding, for example, duration of hospitalization, intensity of care and limitation of the activity. In this paper, we propose a standardized CT technique and the main symptomatology that determines the severity of the damage of abdominal organs in children, based on own experience, taking into account the world literature data on CT.

Magnetic resonance spectroscopy (MRS) is the only method that allows in vivo study of biochemical processes in norm and pathology. The aim of the study was to identify the effect of mild traumatic brain injury (mTBI) on the concentrations of the most important cerebral metabolites and pH values in the human brain according to 1H MRC data.

In this study, the concentrations of major inhibitory (γ-amino butyric acid) and excitatory (glutamate) neurotransmitters have been estimated for the first time in the norman appearing brain tissue in children with mild traumatic brain injury using magnetic resonance and computer tomography data. 1H magnetic resonance spectra were processed with the J-difference editing technique. It was shown that after mild traumatic brain injury, the concentration of γ-amino butyric acid increases (by 36%) in the frontal lobes, that shifts the inhibitory/excitatory (γ-amino butyric acid/glutamate) balance. It is found that using standart MEGA-PRESS pulse sequence for γ-amino butyric concentration quantification leads to masking the effect of γ-amino butyric acid alteration because the collected signal consists of the signals produced from protons of γ-methylene group of the γ-amino butyric acid and signals from protons of mobile amino-acid chains of proteins. Therefore, a pulse sequence should be modified with symmetrical suppression of signals from mobile amino-acid chains of proteins.

Wide-spread visualization methods which are computed tomography (CT) and magnetic resonance imaging (MRI) are not sensitive to mild traumatic brain injury (mTBI). However, mTBI may cause changes of cerebral microstructure that could be found using diffusion-tensor imaging. The aim of this study is to reveal the impact of acute mTBI (no more than 3 days after trauma) on diffusion parameters in corpus callosum, corticospinal tract, and thalamus in children (aged 14-18). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were analyzed. Significant increase in FA and decrease in ADC were observed in thalamus. The trend to an increase in FA is observed in corpus callosum.

Bone mineral density is an important parameter that determines strength of the bone. Decrease in bone mineral density (BMD) leads to dangerous skeletal diseases like osteopenia, osteoporosis and an increased risk of fractures, for instance compression vertebral fracture (CVF). Dual-energy x-ray absorptiometry (DXA) and quantitative CT (QCT) are commonly accepted methods for assessing of the BMD. Previously FF was shown to increase in adult patients with osteoporosis as compared to healthy volunteers. The aim of the study was to explore the relationship between FF and BMD in children. Correlation analysis revealed significant inverse correlation link (p1H MRS could be good alternative to QCT and DXA without radiation dose in osteoporosis detection. Revealed significant negative correlation between FF and BMD in children without osteoporosis suggests that the processes of increasing FF in the bone marrow and lowering the BMD are parallel. Therefore, 1H MRS could be good alternative to QCT and DXA without radiation dose in osteoporosis detection.

The aim of this study is to elucidate the effect of one HBO session on the concentrations of metabolites detectible by 1H and 31P magnetic resonance spectroscopy. An activation of energy metabolism that manifested in the decrease of creatinephosphate (PCr), pHint and increase α-ATP signal after a HBO session is revealed. Other ATP resonances remain unchanged. Also the reduction of N-acetyl aspartate by 3% in mediolateral prefrontal cortex (MPFC) with p2.

For the first time the intracellular concentrations of N-acetylaspartate (NAA), aspartate (Asp), and glutamate (Glu) were measured in human brain in vivo, and the effect of severe traumatic brain injury on NAA synthesis in acute and remote posttraumatic phases was revealed. In non-damaged (MRI-negative) lobes the next day after injury, Asp and Glu decreased by 45% and 35%, respectively, while NAA decreased only by 16%. A negative correlation between NAA and Asp/Glu ratio was found. The Glu level returned to the norm long after injury, Asp remained below the norm by 60%, NAA decreased by 65% relative to the norm, and Asp/Glu decreased significantly. The results obtained educe the leading role of neuronal aspartate-malate shuttle in NAA synthesis alterations.

The intravital level of γ-aminobutyric acid (GABA) was measured for the first time and the imbalance of the key excitatory and inhibitory neurotransmitters in the brain frontal lobes of patients with ultra-high risk for schizophrenia was studied. The proton magnetic resonance spectroscopy (1H MRS) with the MEGA-PRESS pulse sequence for separating the superimposed signals was used. The area of interest was the anterior cingulate cortex with account for lateralization in the right and left brain hemispheres. A statistically significant decrease in the GABA concentration (by 25%) and in the [GABA]/[GLX] ratio (GLX is glutamate + glutamine) (by 20%) were found for the patients in the left brain hemisphere, this ratio in the right brain hemisphere remaining at the normal level.