Spatial characterization of the magnetic field profile of a probe tip used in magnetic resonance force microscopy

We have developed the experimental approach to characterize spatial distribution of the magnetic field produced by cantilever tips used in magnetic resonance force microscopy (MRFM). We performed MRFM measurements on a well characterized diphenyl-picrylhydrazyl (DPPH) film and mapped the 3D field profile produced by a Nd2Fe14B probe tip. Using our technique field profiles of arbitrarily shaped probe magnets can be imaged.Comment: 10 pages, 5 figure

П. А. Куприянов и его работа в Первом Ленинградском медицинском институте: «С глубоким проникновением в детали избранной специальности»

Since 1926, Peter Andreevich Kupriyanov served at Z.P. Solovyov Central Red Army Military Hospital of Leningrad and simultaneously began to work part-time at Pavlov First Medical Institute of Leningrad. This article talks about the work of P.A. Kupriyanov at The First Medical Institute of Leningrad from 1926 to 1948.С 1926 г. Петр Андреевич Куприянов служит в Ленинградском Центральном Красноармейском Военном госпитале им. З. П. Соловьева и, одновременно по совместительству, начинает работать в Первом Ленинградском медицинском институте им. акад. И. П. Павлова. В настоящей статье отражена работа П. А. Куприянова в 1-м ЛМИ в период с 1926 по 1948 г

Reply to: New Meta- and Mega-analyses of Magnetic Resonance Imaging Findings in Schizophrenia: Do They Really Increase Our Knowledge About the Nature of the Disease Process?

This work was supported by National Institute of Biomedical Imaging and Bioengineering Grant No. U54EB020403 (to the ENIGMA consortium)

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

Cortical brain abnormalities in 4474 individuals with schizophrenia and 5098 control subjects via the enhancing neuro Imaging genetics through meta analysis (ENIGMA) Consortium

BACKGROUND: The profile of cortical neuroanatomical abnormalities in schizophrenia is not fully understood, despite hundreds of published structural brain imaging studies. This study presents the first meta-analysis of cortical thickness and surface area abnormalities in schizophrenia conducted by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) Schizophrenia Working Group. METHODS: The study included data from 4474 individuals with schizophrenia (mean age, 32.3 years; range, 11-78 years; 66% male) and 5098 healthy volunteers (mean age, 32.8 years; range, 10-87 years; 53% male) assessed with standardized methods at 39 centers worldwide. RESULTS: Compared with healthy volunteers, individuals with schizophrenia have widespread thinner cortex (left/right hemisphere: Cohen's d = -0.530/-0.516) and smaller surface area (left/right hemisphere: Cohen's d = -0.251/-0.254), with the largest effect sizes for both in frontal and temporal lobe regions. Regional group differences in cortical thickness remained significant when statistically controlling for global cortical thickness, suggesting regional specificity. In contrast, effects for cortical surface area appear global. Case-control, negative, cortical thickness effect sizes were two to three times larger in individuals receiving antipsychotic medication relative to unmedicated individuals. Negative correlations between age and bilateral temporal pole thickness were stronger in individuals with schizophrenia than in healthy volunteers. Regional cortical thickness showed significant negative correlations with normalized medication dose, symptom severity, and duration of illness and positive correlations with age at onset. CONCLUSIONS: The findings indicate that the ENIGMA meta-analysis approach can achieve robust findings in clinical neuroscience studies; also, medication effects should be taken into account in future genetic association studies of cortical thickness in schizophrenia

THE PREVENTION OF PULMONARY EMBOLISM FOLLOWING ENDOVENOUS LASER COAGULATION OF VARICOSE VEINS OF THE LOWER LIMBS

OBJECTIVE. The aim of the research was to compare the influence of the endovenous laser coagulation (EVLC) on the pulmonary system with the performing of the Troyanov–Trendelenburg operation and without it. MATERIAL AND METHODS. We performed 108 endovenous laser coagulation for 16 patients without great saphenous vein trunk dressing and for 92 patients with dressing. The Russian portable laser device «Diolan» was used for the endovenous laser coagulation, wavelength of 980 nm, capacity of 16–20 watts. An intraoperative transesophageal echocardiography was carried to 12 patients to visualize heart chambers in the moment of the laser exposure. RESULTS. The patients without Troyanov–Trendelenburg operation had massive inflow of gas bubbles and detritus into pulmonary system during the endovenous laser coagulation. CONCLUSION. The obtained results showed the qualitative and quantitative differences in the character of the substrate entering the heart and the pulmonary system

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

P. A. Kupriyanov and his work at The First Medical Institute of Leningrad: «With deep insight into the nuances of the chosen specialty»

Since 1926, Peter Andreevich Kupriyanov served at Z.P. Solovyov Central Red Army Military Hospital of Leningrad and simultaneously began to work part-time at Pavlov First Medical Institute of Leningrad. This article talks about the work of P.A. Kupriyanov at The First Medical Institute of Leningrad from 1926 to 1948