Исследование нарушений функциональных связей между сетью пассивного режима работы мозга и структурами мозжечка у пациентов с легкой черепно-мозговой травмой в острой стадии по данным фМРТ состояния покоя

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.Легкая черепно-мозговая травма (лЧМТ) является наиболее распространенным неврологическим повреждением у детей, поэтому чрезвычайно важно идентифицировать и проанализировать биомаркеры, которые могут помочь в процессах лечения и выздоровления пациента с лЧМТ.Цель исследования: подтвердить гипотезу о том, что нарушения функциональных связей между неповрежденным мозжечком и узлами сети DMN включены в симптоматическое проявление лЧМТ.Методы. Обследованы 28 МР-негативных пациентов с лЧМТв возрасте от 12 до 17 лет (средний возраст 14,7 года). Контрольная группа состояла из 23 здоровых детей. Все МРТ-исследования проводились на сканере Philips Achieva dStream 3,0 Tл, оборудованном 32-канальной головной катушкой Philips dStream. Проведена фМРТ состояния покоя (EPI последовательность, TR = 3000 мс, время эха (TE) = 30 мс, 80 динамиков с динамическим временем сканирования 3 с). Данные фМРТ обработаны с использованием программного пакета CONN.Результаты. Не обнаружено статистически значимого различия в значениях коэффициентов функциональных связей между областями сети DMN в группах пациентов и контроля. Межгрупповой анализ выявил статистически значимое (р < 0,05) различие в нейронных связях между частями DMN и червем мозжечка (vermis, структурная часть мозжечка): положительная связь в контрольной группе и отрицательная связь в группе пациентов.Заключение. Выявленные изменения в нейрональных связях между областями DMN и мозжечка у пациентов с лЧМТ в остром периоде могут быть начальным этапом повреждений, приводящих к когнитивному дефициту, который может развиться в будущем

Возможности магнитно-резонансной томографии в диагностике острого асептического сакроилиита у детей

INTRODUCTION: Children and adolescents with juvenile spondyloarthritis (JSA) are at risk of developing sacroiliitis. MRI is the most preferred method of diagnosing sacroiliitis in adults over radiography and computed tomography. However, in the case of diagnosing childhood sacroiliitis, there is little information about the capabilities of MRI, and the reliability of the results in studies varies.OBJECTIVE: To show the possibilities of MRI in the diagnosis of infectious-allergic sacroiliitis.MATERIALS AND METHODS.: In this report, we present an analysis of data from 16 patients with aseptic (infectious-allergic) sacroiliitis only. Boys and girls aged 6 to 17 years (mean age 12.2±4.9) were equally divided. Magnetic resonance imaging, including contrast-enhanced imaging (used in 14 patients out of the total), was performed on a 3 T scanner (Achieva dStream Phillips) using a standard protocol that included multiplanar 3D T1-, T2WI, FLAIR and STIR with oblique coronal projection, diffusion-weighted images (DWI).RESULTS: MRI in all 16 patients revealed changes, even in those cases when X-ray and CT did not reveal pathological changes in bone or the changes were on the verge of normal (n=15). Of the 16 children, 10 (62.5%) had unilateral changes (50% on the right, 50% on the left) and six (37.5%) had bilateral changes. The bone marrow edema affected the sacrum in 10 patients, the ilium in three, and both bones of the joint in three patients. On DWI (10 children), increased diffusion was observed in five patients, on the right — in three, and on the left — in two patients.CONCLUSION: Currently, the best imaging modality for suspected acute sacroiliitis is MRI, which is more sensitive and specific, allowing early diagnosis of the disease and, accordingly, initiation of treatment, improving the prognosis. Disadvantages of MRI are long scan times, susceptibility to motion artifacts that require sedation or anesthesia in young children.ВВЕДЕНИЕ: Дети и подростки с ювенильным спондилоартритом (ЮСA) подвержены риску развития сакроилиита. МРТ является наиболее предпочтительным, чем рентгенография и компьютерная томография, методом диагностики сакроилиита у взрослых. Однако в случае диагностики детского сакроилиита недостаточно информации о возможностях МРТ, а надежность результатов в исследованиях варьируется.ЦЕЛЬ: Показать возможности МРТ в диагностике инфекционно-аллергического сакроилиита.МАТЕРИАЛЫ И МЕТОДЫ: В данном сообщении мы приводим анализ данных 16 пациентов только с асептическим (инфекционно-аллергический) сакроилиитом. Мальчиков и девочек в возрасте от 6 до 17 лет (средний возраст 12,2±4,9 года) было поровну. Магнитно-резонансная томография, в том числе с контрастным усилением (применена у 14 пациентов из общего числа), проведена на томографе 3 Тл (Achieva dStream Phillips) с использованием стандартного протокола, который включал мультипланарные 3D T1-, T2-ВИ, FLAIR и STIR с косой коронарной проекцией, диффузионно-взвешенные изображения (ДВИ).РЕЗУЛЬТАТЫ: МРТ у всех 16 больных выявила изменения, даже в тех наблюдениях, когда рентгенография и КТ костных патологических изменений не выявили или изменения были на грани нормы (n=15). Из 16 детей у 10 (62,5%) имелись односторонние изменения (50% справа, 50% слева) и шести (37,5%) двусторонние изменения. Отек костного мозга затронул крестец у 10 пациентов, подвздошную кость у трех и обе кости сустава у трех пациентов. На ДВИ (10 детей) повышенная диффузия наблюдалась у пяти пациентов, справа — у трех и слева — у двух пациентов.ЗАКЛЮЧЕНИЕ: В настоящее время лучшим методом визуализации при подозрении на острый сакроилиит является МРТ, которая более чувствительна и специфична, что позволяет диагностировать заболевание на ранней стадии и соответственно начать лечение, улучшить прогноз. Недостатками МРТ являются длительное время сканирования, подверженность артефактам движения, которые требует седации или анестезии у маленьких детей

Роль магнитно-резонансной томографии при острой травме шейного отдела позвоночника у детей

Aim. To evaluate the role of magnetic resonance imaging (MRI) as a diagnostic method in children with acute trauma of the cervical spine and spinal cord, to compare the correspondence of MRI results with neurologic symptoms in accordance with the ASIA scale.Materials and methods. 156 children with acute trauma of spine and spinal cord at the age from 6 months up to 18 years were studied. MRI was performed on a Phillips Achieva 3T scanner. The standard protocol included MYUR (myelography) in coronal and sagittal projections, STIR and T2VI FS SE in sagittal projection, T2VI SE or T2 * VI FSGE (axial projection), 3D T1VI FSGE before and after contrast enhancement. Contrast substance was injected intravenously in the form of a bolus at the rate of 0.1 mmol/kg (equivalent to 0.1 ml/kg) at a rate of 3 to 4 ml.Results. The causes of cervical spine blunt trauma were: road accidents (55), catatrauma (60), “diver” trauma (21), blunt trauma (20). Intramedullary lesions of the spinal cord were detected: concussion (49), bruising / crushing (27), hematomia (34), disruption with divergence of segments (21), accompanied by edema (141); extramedullary lesions: epi- and subdural, intralesive and sub-connective and soft tissues hematomas (68), ruptures of bundles (48), fractures (108), dislocation and subluxation of the vertebrae (35), traumatic disc herniation (37), spinal cord compression and/or rootlets (63), statics violation (134), instability (156).Conclusion. MRI is the optimal method for spinal cord injury diagnostics. In the acute period of injury this technique has limited application, but it can however serve as a primary diagnostic method in these patients. MRI should be performed no later than the first 72 hours after injury. The most optimal for visualization of cervical spine trauma and spinal cord are T2VI SE and STIR in sagittal projection with suppression of signal from fat. MRI results correlate with neurologic symptoms at the time of performance according to the ASIA scale, and therefore MRI should be performed in all patients with acute cervical spine trauma, whenever possible.Цель исследования: оценить роль магнитно-резонансной томографии (МРТ) в качестве метода диагностики у детей с травмой шейного отдела позвоночника и спинного мозга, сравнить соответствие результатов МРТ с неврологическими симптомами и шкалой ASIA.Материал и методы. Исследовано 156 детей с острой травмой позвоночника и спинного мозга в возрасте от 6 мес до 18 лет. МРТ проводилась на томографе Phillips Achieva 3 Тл. Стандартный протокол исследования включал: миелографию (MYUR) в коронарной и сагиттальной проекциях, STIR и Т2ВИ FS SE в сагиттальной проекции, Т2ВИ SE или Т2ВИ FSGE (аксиальная проекция), 3D Т1ВИ FSGE до и после контрастного усиления. Контрастное вещество вводилось внутривенно в виде болюса из расчета 0,1 ммоль/кг (эквивалентно 0,1 мл/кг) со скоростью 3–4 мл.Результаты. Причинами тупой травмы шейного отдела позвоночника явились: дорожно-транспортные происшествия (55), кататравма (60), травма “ныряльщика” (21), тупая травма (20). Были выявлены интрамедуллярные повреждения спинного мозга: сотрясение (49), ушиб/размозжение (27), гематомиелия (34), разрыв с расхождением отрезков (21), сопровождавшиеся отеком (141); экстрамедуллярные повреждения: эпии субдуральные, внутри- и подсвязочные и гематомы мягких тканей (68), разрывы связок (48), переломы (108), вывих и подвывих позвонков (35), травматические грыжи диска (37), компрессия спинного мозга и/или корешков (63), нарушение статики (134), нестабильность (156).Заключение. МРТ – оптимальный метод диагностики позвоночно-спинномозговой травмы. В острый период травмы она имеет ограниченное применение, но однако может служить методом первичной диагностики у этих больных. МРТ желательно выполнять не позднее первых 72 ч после травмы. Наиболее оптимальными для визуализации травмы шейного отдела позвоночника и спинного мозга являются Т2ВИ SE и STIR в сагиттальной проекции с подавлением сигнала от жира. Результаты МРТ на момент выполнения коррелируют с неврологической симптоматикой в соответствии со шкалой ASIA, а поэтому МРТ следует проводить у всех пациентов с острой травмой шейного отдела позвоночника, когда это возможно

Компьютерная томография при переломах голеностопного сустава у детей

Introduction. Correct diagnosis is based on visualization and knowledge of fracture patterns characteristic of children. Traditionally, radiography is used to visualize bone damage. In fractures in children due to the high risk of damage to the germinal zones, it is necessary to have clear and reliable information about their condition, which cannot always be obtained by x-ray method. For these purposes and the requirements of modern surgery, CT is used, which with high diagnostic accuracy clarifies the degree of displacement of fragments, present a qualitative characteristic of fractures and reveals associated damage.Purpose: to show the capabilities of computed tomography in diagnosis of fractures of ankle joint.Materials and methods. The results of computed tomography (CT) are presented in 226 children and adolescents aged 3 to 17 years. There were 142 boys (62.8%), 84 girls (37.2%). Scanning was carried out depending on the weight and age of the patient with the minimum indicators of kV and mAS, a slice thickness of 0.75 mm.Results. Average time for seeking medical help was 32 hours from moment of injury. Among causes of injury in the first place was domestic injury (73, 8%), followed by sports injury (22, 3%) and traffic accidents (3.9%). Right-sided ankle fractures were found in 147 (65.1%), left-sided – in 79 (34.9%) children. The most common types of tibial fractures were metaepiphysiolysis of the distal tibia and metaepiphysiolysis of the distal tibia of both tibia, which together accounted for 67.7% (n = 153) of all tibial fractures.Conclusion. Computed tomography should be performed in all cases of intraarticular fractures of the ankle joint. It is especially important for evaluating fractures with damage to germ zones. Scanning must be carried out with a cutting thickness of not more than 1 mm. CT with multi-planar data reformatting is an important factor in determining whether a patient needs surgical treatment. As a result of CT, a final diagnosis was established and a decision was made on treatment tactics.Введение. Правильная диагностика базируется на визуализации и знании паттернов переломов, характерных для детей. Традиционно для визуализации костных повреждений используется рентгенография. При переломах у детей из-за высокого риска повреждения ростковых зон необходимо иметь четкую и достоверную информацию об их состоянии, которая не всегда может быть получена при рентгенографии. Для этих целей и требований современной хирургии используется компьютерная томография (КТ), которая с высокой диагностической точностью уточняет степень смещения отломков, позволяет представить качественную характеристику переломов, выявляет сопутствующие повреждения.Цель исследования: показать возможности КТ в диагностике переломов голеностопного сустава.Материал и методы. Представлены результаты КТ у 226 детей и подростков в возрасте от 3 до 17 лет. Мальчиков было 142 (62,8%), девочек 84 (37,2%). Сканирование проводилось в зависимости от масы тела и возраста пациента с минимальными показателями kV и mAS, толщиной среза 0,75 мм.Результаты. Среднее время обращения за медицинской помощью составило 32 ч от момента травмы. Среди причин травматизма на первом месте была бытовая травма (73, 8%), далее – спортивная травма (22, 3%) и дорожно-транспортные происшествия (3,9%). Правосторонние переломы голеностопного сустава были у 147 (65,1%), левосторонние – у 79 (34,9%) детей. Наиболее частыми видами переломов костей голени были метаэпифизиолиз дистального отдела большеберцовой кости и метаэпифизеолизы дистальных отделов обеих костей голени, которые в сумме составили 67,7% (n = 153) от всех переломов голени.Заключение. КТ необходимо выполнять во всех случаях внутрисуставных переломов голеностопного сустава. Особенно она важна для оценки переломов с повреждением ростковых зон. Сканирование необходимо проводить с толщиной среза не более 1 мм. КТ с мультипланарным переформатированием данных является важным фактором в определении того, нуждается ли пациент в хирургическом лечении. В результате проведения КТ устанавливался окончательный диагноз и принималось решение о тактике лечения

Frequency drift in MR spectroscopy at 3T

Purpose: Heating of gradient coils and passive shim components is a common cause of instability in the B-0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered during MR spectroscopy (MRS) to assess the need for real-time field-frequency locking on MRI scanners by comparing field drift data from a large number of sites.Method: A standardized protocol was developed for 80 participating sites using 99 3T MR scanners from 3 major vendors. Phantom water signals were acquired before and after an EPI sequence. The protocol consisted of: minimal preparatory imaging; a short pre-fMRI PRESS; a ten-minute fMRI acquisition; and a long post-fMRI PRESS acquisition. Both pre- and post-fMRI PRESS were non-water suppressed. Real-time frequency stabilization/adjustment was switched off when appropriate. Sixty scanners repeated the protocol for a second dataset. In addition, a three-hour post-fMRI MRS acquisition was performed at one site to observe change of gradient temperature and drift rate. Spectral analysis was performed using MATLAB. Frequency drift in pre-fMRI PRESS data were compared with the first 5:20 minutes and the full 30:00 minutes of data after fMRI. Median (interquartile range) drifts were measured and showed in violin plot. Paired t-tests were performed to compare frequency drift pre- and post-fMRI. A simulated in vivo spectrum was generated using FID-A to visualize the effect of the observed frequency drifts. The simulated spectrum was convolved with the frequency trace for the most extreme cases. Impacts of frequency drifts on NAA and GABA were also simulated as a function of linear drift. Data from the repeated protocol were compared with the corresponding first dataset using Pearson's and intraclass correlation coefficients (ICC).Results: Of the data collected from 99 scanners, 4 were excluded due to various reasons. Thus, data from 95 scanners were ultimately analyzed. For the first 5:20 min (64 transients), median (interquartile range) drift was 0.44 (1.29) Hz before fMRI and 0.83 (1.29) Hz after. This increased to 3.15 (4.02) Hz for the full 30 min (360 transients) run. Average drift rates were 0.29 Hz/min before fMRI and 0.43 Hz/min after. Paired t-tests indicated that drift increased after fMRI, as expected (p &lt; 0.05). Simulated spectra convolved with the frequency drift showed that the intensity of the NAA singlet was reduced by up to 26%, 44 % and 18% for GE, Philips and Siemens scanners after fMRI, respectively. ICCs indicated good agreement between datasets acquired on separate days. The single site long acquisition showed drift rate was reduced to 0.03 Hz/min approximately three hours after fMRI.Discussion: This study analyzed frequency drift data from 95 3T MRI scanners. Median levels of drift were relatively low (5-min average under 1 Hz), but the most extreme cases suffered from higher levels of drift. The extent of drift varied across scanners which both linear and nonlinear drifts were observed.</p

The preliminary diffusion tensor imaging study of cerebral microstructure in the acute phase of brain concussion

Purpose of the study. Concussion does not cause any lesions available for visualization using computed tomography and magnetic resonance imaging. However, it can cause changes at the microstructural level, which can be detected by the diffusion-tensor imaging. The purpose of this study is to identify the effect of acute concussion on diffusion parameters in the corpus callosum, corticospinal tract, and thalamus in children.Patients and methods. Fractional anisotropy and the apparent diffusion coefficient were determined in 11 patients with a diagnosis of concussion (41 ± 19 hours from the moment of injury) and in 11 healthy subjects. Philips Achieva dStream 3T magnetic resonance imager was used. Diffusion tensor imaging data were processed in the Philips Intellispace Portal program in the Fibertrack section.Results. Fractional diffusion anisotropy significantly increases and the apparent diffusion coefficient decreases in the thalamus of patients with concussion. In corpus callosum there is a growth trend in fractional anisotropy.Conclusion. The detected changes indicate the initial stage of cell edema in the thalamus caused by concussion. Diffusion-tensor imaging is the only magnetic resonance imaging method which may be sensitive to this pathology

Frequency drift in MR spectroscopy at 3T.

PurposeHeating of gradient coils and passive shim components is a common cause of instability in the B0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered during MR spectroscopy (MRS) to assess the need for real-time field-frequency locking on MRI scanners by comparing field drift data from a large number of sites.MethodA standardized protocol was developed for 80 participating sites using 99 3T MR scanners from 3 major vendors. Phantom water signals were acquired before and after an EPI sequence. The protocol consisted of: minimal preparatory imaging; a short pre-fMRI PRESS; a ten-minute fMRI acquisition; and a long post-fMRI PRESS acquisition. Both pre- and post-fMRI PRESS were non-water suppressed. Real-time frequency stabilization/adjustment was switched off when appropriate. Sixty scanners repeated the protocol for a second dataset. In addition, a three-hour post-fMRI MRS acquisition was performed at one site to observe change of gradient temperature and drift rate. Spectral analysis was performed using MATLAB. Frequency drift in pre-fMRI PRESS data were compared with the first 5:20 minutes and the full 30:00 minutes of data after fMRI. Median (interquartile range) drifts were measured and showed in violin plot. Paired t-tests were performed to compare frequency drift pre- and post-fMRI. A simulated in vivo spectrum was generated using FID-A to visualize the effect of the observed frequency drifts. The simulated spectrum was convolved with the frequency trace for the most extreme cases. Impacts of frequency drifts on NAA and GABA were also simulated as a function of linear drift. Data from the repeated protocol were compared with the corresponding first dataset using Pearson's and intraclass correlation coefficients (ICC).ResultsOf the data collected from 99 scanners, 4 were excluded due to various reasons. Thus, data from 95 scanners were ultimately analyzed. For the first 5:20 min (64 transients), median (interquartile range) drift was 0.44 (1.29) Hz before fMRI and 0.83 (1.29) Hz after. This increased to 3.15 (4.02) Hz for the full 30 min (360 transients) run. Average drift rates were 0.29 Hz/min before fMRI and 0.43 Hz/min after. Paired t-tests indicated that drift increased after fMRI, as expected (p &lt; 0.05). Simulated spectra convolved with the frequency drift showed that the intensity of the NAA singlet was reduced by up to 26%, 44 % and 18% for GE, Philips and Siemens scanners after fMRI, respectively. ICCs indicated good agreement between datasets acquired on separate days. The single site long acquisition showed drift rate was reduced to 0.03 Hz/min approximately three hours after fMRI.DiscussionThis study analyzed frequency drift data from 95 3T MRI scanners. Median levels of drift were relatively low (5-min average under 1 Hz), but the most extreme cases suffered from higher levels of drift. The extent of drift varied across scanners which both linear and nonlinear drifts were observed

Frequency drift in MR spectroscopy at 3T

Purpose: Heating of gradient coils and passive shim components is a common cause of instability in the B-0 field, especially when gradient intensive sequences are used. The aim of the study was to set a benchmark for typical drift encountered during MR spectroscopy (MRS) to assess the need for real-time field-frequency locking on MRI scanners by comparing field drift data from a large number of sites. Method: A standardized protocol was developed for 80 participating sites using 99 3T MR scanners from 3 major vendors. Phantom water signals were acquired before and after an EPI sequence. The protocol consisted of: minimal preparatory imaging; a short pre-fMRI PRESS; a ten-minute fMRI acquisition; and a long post-fMRI PRESS acquisition. Both pre- and post-fMRI PRESS were non-water suppressed. Real-time frequency stabilization/adjustment was switched off when appropriate. Sixty scanners repeated the protocol for a second dataset. In addition, a three-hour post-fMRI MRS acquisition was performed at one site to observe change of gradient temperature and drift rate. Spectral analysis was performed using MATLAB. Frequency drift in pre-fMRI PRESS data were compared with the first 5:20 minutes and the full 30:00 minutes of data after fMRI. Median (interquartile range) drifts were measured and showed in violin plot. Paired t-tests were performed to compare frequency drift pre- and post-fMRI. A simulated in vivo spectrum was generated using FID-A to visualize the effect of the observed frequency drifts. The simulated spectrum was convolved with the frequency trace for the most extreme cases. Impacts of frequency drifts on NAA and GABA were also simulated as a function of linear drift. Data from the repeated protocol were compared with the corresponding first dataset using Pearson's and intraclass correlation coefficients (ICC). Results: Of the data collected from 99 scanners, 4 were excluded due to various reasons. Thus, data from 95 scanners were ultimately analyzed. For the first 5:20 min (64 transients), median (interquartile range) drift was 0.44 (1.29) Hz before fMRI and 0.83 (1.29) Hz after. This increased to 3.15 (4.02) Hz for the full 30 min (360 transients) run. Average drift rates were 0.29 Hz/min before fMRI and 0.43 Hz/min after. Paired t-tests indicated that drift increased after fMRI, as expected (p < 0.05). Simulated spectra convolved with the frequency drift showed that the intensity of the NAA singlet was reduced by up to 26%, 44 % and 18% for GE, Philips and Siemens scanners after fMRI, respectively. ICCs indicated good agreement between datasets acquired on separate days. The single site long acquisition showed drift rate was reduced to 0.03 Hz/min approximately three hours after fMRI. Discussion: This study analyzed frequency drift data from 95 3T MRI scanners. Median levels of drift were relatively low (5-min average under 1 Hz), but the most extreme cases suffered from higher levels of drift. The extent of drift varied across scanners which both linear and nonlinear drifts were observed