МРТ мышц / МРТ всего тела в диагностике и динамическом наблюдении пациентов с нервно-мышечными заболеваниями

The use of MRI in myopathies dates back to more than 20 years. The first investigations were slow and only allowed segmental and limited studies. Whole-body MRI has emerged over the past twelve years and became a useful diagnostic tool in the etiological diagnosis of myopathies and muscular dystrophies. This study must always be confronted with clinical and whichever other paraclinical data without being able to replace them. Indications to perform such an investigation are getting better and better defined and the diagnostic efficacy has progressed with the increasing number of cases, communications, publications and discussions within multidisciplinary working groups. Its noninvasive nature, the radiation-free exposure and its reasonable cost also enable this technique to be easily accepted by the patient. It also provides a valuable tool for monitoring the natural disease progression or the effectiveness of therapies. The radiology team must be acquainted with the management of neuromuscular patients. Interpreting muscle whole-body MRI requires an excellent knowledge of muscle anatomy whichever body part is examined. The radiologist performing these studies is ideally a specialist of musculoskeletal disorders or a neuroradiologist well trained in muscle anatomy.Магнитно-резонансная томография (МРТ) при первично-мышечной патологии используется в клинической практике более 20 лет. Широкое внедрение МРТ в первые годы было ограничено чрезмерной продолжительностью исследования и невозможностью обследования более одного сегмента. Около 12 лет назад в клиническую практику была внедрена МРТ всего тела, ставшая полезной диагностической методикой в ходе определения типа заболевания. Результаты данного исследования требуют обязательного сопоставления с клинической картиной и параклиническими данными и ни в коем случае не должны их заменять. По мере понимания роли МРТ мышц / МРТ всего тела отмечается тенденция к более четкой постановке задачи для специалиста по МРТ, что наряду с накоплением собственного опыта, мультидисциплинарным подходом, сотрудничеством европейских команд исследователей, специализирующихся на нервно-мышечной патологии, увеличило информативность МРТ мышц. Отсутствие лучевой нагрузки, неинвазивность и умеренная стоимость делают данную методику доступной для пациента, а также позволяют использовать в оценке динамики естественного течения заболевания или его изменений на фоне терапии. Радиологическая команда, осуществляющая МРТ мышц / МРТ всего тела, должна иметь опыт работы с пациентами-инвалидами, как взрослыми, так и детьми. Интерпретация полученных результатов независимо от исследуемой зоны требует досконального знания анатомии мышц. В идеале радиолог, осуществляющий исследования, должен быть специалистом по мышечно-скелетной патологии или нейрорадиологом, специализирующимся на заболеваниях мышц

Physical modelling of chemical compaction, overpressure development, hydraulic fracturing and thrust detachments in organic-rich source rock

International audienceGeological evidence for overpressure is common worldwide, especially in petroleum-rich sedimentary basins. As a result of an increasing emphasis on unconventional resources, new data are becoming available for source rocks. Abnormally high values of pore fluid pressure are especially common within mature source rock, probably as a result of chemical compaction and increases in volume during hydrocarbon generation. To investigate processes of chemical compaction, overpressure development and hydraulic fracturing, we have developed new techniques of physical modelling in a closed system. During the early stages of our work, we built and deformed models in a small rectangular box (40 40 10 cm), which rested on an electric flatbed heater; but more recently, in order to accommodate large amounts of horizontal shortening, we used a wider box (77 75 10 cm). Models consisted of horizontal layers of two materials: (1) a mixture of equal initial volumes of silica powder and beeswax micro-spheres, representing source rock, and (2) pure silica powder, representing overburden. By submerging these materials in water, we avoided the high surface tensions, which otherwise develop within pores containing both air and liquids. Also we were able to measure pore fluid pressure in a model well. During heating, the basal temperature of the model surpassed the melting point of beeswax (w62 C), reaching a maximum of 90 C. To investigate tectonic contexts of compression or extension, we used a piston to apply horizontal displacements. In experiments where the piston was static, rapid melting led to vertical compaction of the source layer, under the weight of overburden, and to high fluid overpressure (lithostatic or greater). Crosssections of the models, after cooling, revealed that molten wax had migrated through pore space and into open hydraulic fractures (sills). Most of these sills were horizontal and their roofs bulged upwards, as far as the free surface, presumably in response to internal overpressure and loss of strength of the mixture.We also found that sills were less numerous towards the sides of the box, presumably as a result of boundary effects. In other experiments, in which the piston moved inward, causing compression of the model, sills also formed. However, these were thicker than in static models and some of them were subject to folding or faulting. For experiments, in which we imposed some horizontal shortening, before the wax had started to melt, fore-thrusts and back-thrusts developed across all of the layers near the piston, producing a high-angle prism. In contrast, as soon as the wax melted, overpressure developed within the source layer and a basal detachment appeared beneath it. As a result, thin-skinned thrusts propagated further into the model, producing a low-angle prism. In some experiments, bodies of wax formed imbricate zones within the source layer. Thus, in these experiments, it was the transformation, from solid wax to liquid wax, which led to chemical compaction, overpressure development and hydraulic fracturing, all within a closed system. According to the measurements of overpressure, load transfer was the main mechanism, but volume changes also contributed, producing supra-lithostatic overpressure and therefore tensile failure of the mixture

Magnetic resonance study of the pineal region: normal pineal gland, simple cysts

A magnetic resonance imaging (MRI) study of the normal pineal gland and pineal simple cysts was performed in 762 cases. A fine section technique (maximum 3 millimeters) enabled most of the times the identifying of a normal pineal in addition to demonstrating that a pineal without any cyst shows an isointense signal in Tl and T2 which, in turn, is enhanced following gadolinium. The measure of the normal pineal was of about 6.1 millimeters in its diameter length. Pineal simple cysts were observed in a 2.6% frequency in relation to the whole series (762 cases); however reaches 6.1% when only the visualized pineals were considered (329 cases). Also, it was found out that simple cysts were not correlated to age or gender. Simple cysts characteristics are: dimension less or equal to 20 millimeters; absence of expansive effect; similar signal to that of the cerebrospinal fluid; absence of cyst growth.Realiza-se um estudo por ressonância magnética da pineal normal e dos cistos simples da pineal e estabelece-se um protocolo para estudo da região pineal analisando-se 762 exames. A utilização da técnica com cortes finos (3 milímetros no máximo) identifica a pineal normal na maioria das vezes (84,4%) e demonstra que a pineal normal, sem cistos, apresenta sinal isointenso em Tl e T2 com realce após a injeção de gadolínio, medindo em média 6,1 milímetros no seu maior diâmetro. Os cistos simples da pineal aparecem com frequência de 2,6% em relação a toda a série (762 casos) elevando-se essa frequência para 6,1% se forem consideradas somente as pineais visiblizadas (329 casos). Os cistos simples não se correlacionam nem com a idade nem com o sexo e os cistos sintomáticos são raros. Os critérios para diagnóstico diferencial dos cistos simples versus tumores da região da pineal são: dimensões menores ou iguais a 20 milímetros; espessura da parede abaixo de 2 milímetros; ausência de efeito expansivo; sinal igual ao líquido cefalorraquidiano e ausência de crescimento dos cistos.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Diagnóstico por ImagemUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Serviço de NeurorradiologiaUniversidade Paris-Sul Centro Hospitalar Universitário de BicêtreUNIFESP, EPM, Depto. de Diagnóstico por ImagemUNIFESP, EPM, Serviço de NeurorradiologiaSciEL

Severity classification in cases of Collagen VI-related myopathy with Convolutional Neural Networks and handcrafted texture features

(C) 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Magnetic Resonance Imaging (MRI) is a non-invasive tool for the clinical assessment of low-prevalence neuromuscular disorders. Automated diagnosis methods might reduce the need for biopsies and provide valuable information on disease follow-up. In this paper, three methods are proposed to classify target muscles in Collagen VI-related myopathy cases, based on their degree of involvement, notably a Convolutional Neural Network, a Fully Connected Network to classify texture features, and a hybrid method combining the two feature sets. The proposed methods were evaluated on axial T1-weighted Turbo Spin-Echo MRI from 26 subjects, including Ullrich Congenital Muscular Dystrophy and Bethlem Myopathy patients at different evolution stages. The hybrid model achieved the best cross-validation results, with a global accuracy of 93.8%, and F-scores of 0.99, 0.82, and 0.95, for healthy, mild and moderate/severe cases, respectively.info:eu-repo/semantics/acceptedVersio

Severity classification in cases of Collagen VI-related myopathy with Convolutional Neural Networks and handcrafted texture features

© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Magnetic Resonance Imaging (MRI) is a non-invasive tool for the clinical assessment of low-prevalence neuromuscular disorders. Automated diagnosis methods might reduce the need for biopsies and provide valuable information on disease follow-up. In this paper, three methods are proposed to classify target muscles in Collagen VI-related myopathy cases, based on their degree of involvement, notably a Convolutional Neural Network, a Fully Connected Network to classify texture features, and a hybrid method combining the two feature sets. The proposed methods were evaluated on axial T1-weighted Turbo Spin-Echo MRI from 26 subjects, including Ullrich Congenital Muscular Dystrophy and Bethlem Myopathy patients at different evolution stages. The hybrid model achieved the best cross-validation results, with a global accuracy of 93.8%, and F-scores of 0.99, 0.82, and 0.95, for healthy, mild and moderate/severe cases, respectively.info:eu-repo/semantics/acceptedVersio

Relationships between radiographic parameters and spinopelvic muscles in adult spinal deformity patients

Introduction While the clinical impact of coronal and sagittal alignment in adult spinal deformity (ASD) patients (pts) is established, there is a paucity of data in terms of axial plane deformity and potential association between muscle degenera- tion and 3D deformity. The purpose of this study was to analyze spinopelvic muscles characteristics in association with the 3D deformity of ASD patients. Methods This is a prospective cohort study; primary lumbar scoliosis patients (Cobb > 20°) were enrolled and sustained a low-dose X-rays with 3D spinal reconstructions and a fat/water separation MRI (from C7 to the knee). Volumetric 3D reconstructions and fat infiltration (FI) of 6 muscles groups were performed. Relationships between muscular data, radio- graphic parameters and health-related quality of life were investigated. Patients were stratified and compared based on the SRS classification, the odontoid-hip axis (ODHA) angle (> or 0.05). Pts with ODHA > 6.1° or pelvic incidence minus lumbar lordosis > 10° had significantly higher FI for the 6 muscular groups, patients with pelvic tilt > 20° had significantly higher FI for erector spinae, hip flexors and extensors (p < 0.05). SF36-PCS significantly correlated with the muscular volume; SRS and Oswestry disability index correlated with the erectors spinae volume (p < 0.05). Conclusion This study analyzed for the first time the relationship between 3D radiographic parameters and muscular charac- teristics in ASD. Sagittal malalignment is associated with increased FI and decreased muscle volumes with poor outcomes