Name: dti of the visual pathway - white matter tracts and cerebral lesions
Uploaded: 2014-08-26T15:00:00
Description: Watch this Scientific Journal Video about DTI of the Visual Pathway - White Matter Tracts and Cerebral Lesions at JoVE.com

We would like to thank the whole Service of Neuroradiology. We would like to thank Lis Prussen for her work in the library.

NOTE: Ce protocole suit les directives du Centre Hospitalier de Luxembourg à Luxembourg. 1 Préparation de Diffusion Tensor Imaging pour la voie visuelle de Neurochirurgie et suivi <ol style="margin-left: 40px;"><li> Effectuer une IRM-scan au moins un jour avant l&#39;intervention strictement axiale en utilisant 32 directions de gradient et un b0 image. Restez en contact étroit avec l&#39;unité de neuroradiologie à tout moment. REMARQUE: Assurez-clair pour le neuroradiologue que...

<ol>
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C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+High-Field+Magnetic+Resonance+Imaging+Combined+With+Fiber+Tract+Neuronavigation-Guided+Resection+of+Cerebral+Lesions+Involving+Optic+Radiation.">Intraoperative High-Field Magnetic Resonance Imaging Combined With Fiber Tract Neuronavigation-Guided Resection of Cerebral Lesions Involving Optic Radiation.</a> Neurosurgery. 69 (5), 1070-1084 (2011).</li><li>Kamada, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+Monitoring+For+Visual+Pathway+Using+Real-Time+Visual+Evoked+Potentials+Aand+Optic-Radiation+Tractography.">Functional Monitoring For Visual Pathway Using Real-Time Visual Evoked Potentials Aand Optic-Radiation Tractography.</a> Neurosurgery. 57 (1 Suppl), 121-127 (2005).</li><li>Wu, W., Rigolo, L., O'Donnell, L. J., Norton, I., Shriver, S., Golby, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visual+Pathway+Study+Using+In+Vivo+Diffusion+Tensor+Imaging+Tractography+to+Complement+Classic+Anatomy.">Visual Pathway Study Using In Vivo Diffusion Tensor Imaging Tractography to Complement Classic Anatomy.</a> Neurosurgery. 70 (1 Suppl Operative), 145-156 (2012).</li><li>Stieglitz, L. H., L&#252;demann, W. O., Giordano, M., Raabe, A., Fahlbusch, R., Samii, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optic+Radiation+Fiber+Tracking+Using+Anteriorly+Angulated+Diffusion+Tensor+Imaging:+A+Tested+Algorithm+for+Quick+Application.">Optic Radiation Fiber Tracking Using Anteriorly Angulated Diffusion Tensor Imaging: A Tested Algorithm for Quick Application.</a> Neurosurgery. 68 (5), 1239-1251 (2011).</li><li>Hodaie, M., Quan, J., Chen, D. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+Vivo+Visualization+of+Cranial+Nerve+Pathways+in+Humans+Using+Diffusion-Based+Tractography.">In Vivo Visualization of Cranial Nerve Pathways in Humans Using Diffusion-Based Tractography.</a> Neurosurgery. 66 (4), 788-795 (2010).</li><li>Perrin, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fiber+tracking+in+Q-ball+fields+using+regularized+particle+trajectories.">Fiber tracking in Q-ball fields using regularized particle trajectories.</a> Inf Process Med Imaging. 19, 52-63 (2005).</li><li>Wedeen, V. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+spectrum+magnetic+resonance+imaging+(DSI)+tractography+of+crossing+fibers.">Diffusion spectrum magnetic resonance imaging (DSI) tractography of crossing fibers.</a> Neuroimage. 41 (4), 1267-1277 (2008).</li><li>Yamamoto, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+Tensor+Fiber+Tractography+of+the+Optic+Radiation:+Analysis+with+6-,+12-,+40-,+and+81-+Directional+Motion-Probing+Gradients,+a+Preliminary+Study.">Diffusion Tensor Fiber Tractography of the Optic Radiation: Analysis with 6-, 12-, 40-, and 81- Directional Motion-Probing Gradients, a Preliminary Study.</a> AJNR Am J Neuroradiol. 28 (1), 92-96 (2007).</li><li>Okada, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+Tensor+Fiber+Tractography+for+Arteriovenous+Malformations:+Quantitative+Analyses+to+Evaluate+the+Corticospinal+Tract+and+Optic+Radiation.">Diffusion Tensor Fiber Tractography for Arteriovenous Malformations: Quantitative Analyses to Evaluate the Corticospinal Tract and Optic Radiation.</a> AJNR Am J Neuroradiol. 28 (6), 1107-1113 (2007).</li><li>Kuhnt, D., Bauer, M. H., Sommer, J., Merhof, D., Nimsky, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optic+Radiation+Fiber+Tractography+in+Glioma+Patients+Based+on+High+Angular+Resolution+Diffusion+Imaging+with+Compressed+Sensing+Compared+with+Diffusion+Tensor+Imaging+-+Initial+Experience.">Optic Radiation Fiber Tractography in Glioma Patients Based on High Angular Resolution Diffusion Imaging with Compressed Sensing Compared with Diffusion Tensor Imaging - Initial Experience.</a> PLoS One. 8 (7), e70973 (2013).</li><li>Basser, P. J., Pajevic, S., Pierpaoli, C., Duda, J., Aldroubi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+fiber+tractography+using+DT-MRI+data.">In vivo fiber tractography using DT-MRI data.</a> Magn Reson Med. 44 (4), 625-632 (2000).</li><li>Friman, O., Farneback, G., Westin, C. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Bayesian+approach+for+stochastic+white+matter+tractography.">A Bayesian approach for stochastic white matter tractography.</a> IEEE Trans Med Imaging. 25 (8), 965-978 (2006).</li><li>Mori, S., van Zijl, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fiber+tracking:+principles+and+strategies+-+a+technical+review.">Fiber tracking: principles and strategies - a technical review.</a> NMR Biomed. 15 (7-8), 468-480 (2002).</li><li>Alexander, D. C., Barker, G. J., Arridge, S. 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DTI est une technique permettant de visualiser le neurochirurgien faisceaux de matière blanche in vivo 8. La voie visuelle est l&#39;un de ces tracts. Bien que cette méthode fournit aux médecins de nouvelles possibilités en ce qui concerne le traitement des patients avec des lésions concernant les régions éloquentes du cerveau, nous devons dire que certaines limites de cette technique font existent encore. La première et la plus évidente est défi cerveau changement, qui reste un problème ?...

L&#39;imagerie du tenseur de diffusion (DTI) est utilisé pour décrire WMT non-invasive du cerveau humain 1. Il a été utilisé dans la dernière décennie pour réduire le risque de porter atteinte à des zones éloquentes du cerveau pendant la chirurgie 1. DTI a été réalisée dans une cinquantaine de patients entre Mars 2012 et Janvier 2014 pour représenter la voie visuelle. DTI pourrait améliorer la conservation des zones éloquentes du cerveau pendant la chirurgie en fournissant des informations importantes sur la localisation anatomique des faisceaux de matière blanche. Il a été incorporé dans la planification stratégique pour la résection de lésions cérébrales complexes 1. Toutefois, la représentation de la voie visuelle demeure un défi, car il n&#39;existe pas de norme pour les paramètres de DTI, le placement des volumes et l&#39;interprétation des résultats 12 graines. Différents algorithmes ont été mis en œuvre à ce jour 19-21. Certaines approches concentrées sur les méthodes déterministes 19, 22-25. D&#39;autres utilisent des méthodes probabilistes, 26,27,29. Plus récemment, des techniques utilisant des champs de tenseurs Q-ball, imagerie de diffusion spectrale et haute résolution angulaire Diffusion Imaging (HARDI) sont utilisés pour dépeindre voies de la matière blanche chez les autres la voie visuelle 1,13-15,18. Toutefois, le temps nécessaire pour HARDI est significativement plus longue avec 45 min, le logiciel n&#39;est pas disponible dans le commerce et met l&#39;accent sur ​​18 des applications scientifiques. La période d&#39;enseignement pour HARDI semble être plus longue que pour DTI 18. Le protocole présenté est facile possible et peut être utilisé pour la routine quotidienne des opérations neurochirurgicales afin d&#39;éviter la morbidité et améliorer le résultat post-opératoire. Le temps supplémentaire pour ce protocole est inférieure à 9 min qui est nettement plus rapide que les autres protocoles 1,9,12,16. Reconnaissant le fait que de nombreux algorithmes sophistiqués ont été développés récemment limité par le papierelle-même à l&#39;aide d&#39;un logiciel disponible dans le commerce et approuvé par la FDA. Cependant il est impératif de tenir compte des limites de cette technique qui sont mentionnés ci-dessus.

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dti of the visual pathway - white matter tracts and cerebral lesions

<html> DTI est une technique qui identifie les secteurs de la substance blanche (WMT) non-invasive chez les patients sains et non sains en utilisant des mesures de diffusion. Semblable à des voies visuelles (VP), WMT ne sont pas visibles à l&#39;IRM classique ou intra-opératoire au microscope. DIT aider les neurochirurgiens pour empêcher la destruction de la VP tout en retirant les lésions adjacentes à cette WMT. Nous avons effectué DTI sur cinquante patients avant et après la chirurgie entre Mars 2012 et Janvier 2014 Pour naviguer, nous avons utilisé une séquence 3DT1 pondéré. En outre, nous avons réalisé un T2 et DTI-séquences. Les paramètres utilisés étaient, FOV: 200 x 200 mm, épaisseur de coupe: 2 mm, et l&#39;acquisition matrice: 96 x 96 voxels rendement presque isotropes de 2 x 2 x 2 mm. Axial IRM a été réalisée en utilisant une direction de gradient et d&#39;une 32 image-b0. Nous avons utilisé Echo-Planar Imaging (EPI) et l&#39;imagerie parallèle d&#39;actifs avec un facteur d&#39;accélération de 2 et b-valeur de 800 s / mm ². Le temps de balayage est inférieure à 9 min. ent &quot;&gt; Les DTI-données obtenues ont été traitées à l&#39;aide d&#39;un FDA a approuvé chirurgicale programme de système de navigation qui utilise une approche fibre de suivi simple connu comme mission de fibre par un suivi continu (FACT). Ceci est basé sur la propagation des lignes entre les régions d&#39;intérêt ( ROI) qui est définie par un médecin. Un angle maximum de 50, la valeur de départ FA de 0,10 et la valeur d&#39;arrêt de l&#39;ADC de 0,20 mm ² / s sont les paramètres utilisés pour la tractographie. Il ya des limites à cette technique. Le délai d&#39;acquisition limitée impose des compromis dans la qualité d&#39;image. Un autre point important à ne pas négliger est le déplacement du cerveau pendant la chirurgie. Quant à la dernière IRM intra-opératoire pourrait être utile. En outre, le risque de faux tracts positifs ou faussement négatifs doit être pris en compte ce qui pourrait compromettre les résultats finaux.

<html> Ce protocole permet au médecin de représenter adéquatement les principales parties de la VP. Il peut être utilisé avec une petite quantité de temps afin d&#39;éviter des dommages chez des patients atteints de lésions cérébrales prochaines zones éloquentes. Contrôles post-opératoires montrent également de bons résultats. VP est représenté dans la figure 7 après que le patient a été opéré d&#39;un glioblastome. Figure 2 montre le vice-président après la réci...

Watch this Scientific Journal Video about DTI of the Visual Pathway - White Matter Tracts and Cerebral Lesions at JoVE.com

DTI of the Visual Pathway - White Matter Tracts and Cerebral Lesions

L&#39;imagerie du tenseur de diffusion (DTI) a été réalisée pour tenter de décrire les principales parties de la voie visuelle. Le but était d&#39;utiliser un poste de travail approuvé par la FDA commercial standard qui pourrait être utilisé pour la routine quotidienne afin d&#39;essayer de réduire les dommages post-opératoire de la voie visuelle chez les patients.

DTI de la voie visuelle - la substance blanche cérébrale Tracts et lésions

DTI is a technique that identifies white matter tracts (WMT) non-invasively in healthy and non-healthy patients using diffusion measurements. Similar to ...

dti-of-the-visual-pathway-white-matter-tracts-and-cerebral-lesions

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JoVE Journal

Medicine

The Application Of Permanent Middle Cerebral Artery Ligation in the Mouse

Focal cerebral ischemia is among the most common type of stroke seen in patients. Due to the clinical significance there has been a prolonged effort to develop suitable animal models to study the events that unfold during ischemic insult. These techniques include transient or permanent, focal or global ischemia models using many different animal models, with the most common being rodents.
The permanent MCA ligation method which is also referred as pMCAo in the literature is used extensively as a focal ischemia model in rodents 1-6. This method was originally described for rats by Tamura et al. in 1981 7. In this protocol a craniotomy was used to access the MCA and the proximal regions were occluded by electrocoagulation. The infarcts involve mostly cortical and sometimes striatal regions depending on the location of the occlusion. This technique is now well established and used in many laboratories 8-13. Early use of this technique led to the definition and description of &#x201C;infarct core&#x201D; and &#x201C;penumbra&#x201D; 14-16, and it is often used to evaluate potential neuroprotective compounds 10, 12, 13, 17. Although the initial studies were performed in rats, permanent MCA ligation has been used successfully in mice with slight modifications 18-20 .
This model yields reproducible infarcts and increased post-survival rates. Approximately 80% of the ischemic strokes in humans happen in the MCA area 21 and thus this is a very relevant model for stroke studies. Currently, there is a paucity of effective treatments available to stroke patients, and thus there is a need for good models to test potential pharmacological compounds and evaluate physiological outcomes. This method can also be used for studying intracellular hypoxia response mechanisms in vivo. 
Here, we present the MCA ligation surgery in a C57/BL6 mouse. We describe the pre-surgical preparation, MCA ligation surgery and 2,3,5 Triphenyltetrazolium chloride (TTC) staining for quantification of infarct volumes.

Middle cerebral artery (MCA) ligation is a technique to study focal cerebral ischemia in animal models. In this method, the middle cerebral artery is exposed by craniotomy and ligated by cauterization. This method gives highly reproducible infarct volumes and increased post-operative survival rates compared to other methods available.

L&#39;application de la ligature permanente artère cérébrale moyenne chez la souris

Focal cerebral ischemia is among the most common type of stroke seen in patients. Due to the clinical significance there has been a prolonged effort to ...

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Médecine

Driving Simulation in the Clinic: Testing Visual Exploratory Behavior in Daily Life Activities in Patients with Visual Field Defects

Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily life, despite similar visual deficits. We assume this could be due to variable development of compensatory strategies such as altered visual scanning behavior. Scanning compensatory therapy (SCT) is studied as part of the visual training after infarction next to vision restoration therapy. SCT consists of learning to make larger eye movements into the blind field enlarging the visual field of search, which has been proven to be the most useful strategy1, not only in natural search tasks but also in mastering daily life activities2. Nevertheless, in clinical routine it is difficult to identify individual levels and training effects of compensatory behavior, since it requires measurement of eye movements in a head unrestrained condition. Studies demonstrated that unrestrained head movements alter the visual exploratory behavior compared to a head-restrained laboratory condition3. Martin et al.4 and Hayhoe et al.5 showed that behavior demonstrated in a laboratory setting cannot be assigned easily to a natural condition. Hence, our goal was to develop a study set-up which uncovers different compensatory oculomotor strategies quickly in a realistic testing situation: Patients are tested in the clinical environment in a driving simulator. SILAB software (Wuerzburg Institute for Traffic Sciences GmbH (WIVW)) was used to program driving scenarios of varying complexity and recording the driver's performance. The software was combined with a head mounted infrared video pupil tracker, recording head- and eye-movements (EyeSeeCam, University of Munich Hospital, Clinical Neurosciences).
The positioning of the patient in the driving simulator and the positioning, adjustment and calibration of the camera is demonstrated. Typical performances of a patient with and without compensatory strategy and a healthy control are illustrated in this pilot study. Different oculomotor behaviors (frequency and amplitude of eye- and head-movements) are evaluated very quickly during the drive itself by dynamic overlay pictures indicating where the subjects gaze is located on the screen, and by analyzing the data. Compensatory gaze behavior in a patient leads to a driving performance comparable to a healthy control, while the performance of a patient without compensatory behavior is significantly worse. The data of eye- and head-movement-behavior as well as driving performance are discussed with respect to different oculomotor strategies and in a broader context with respect to possible training effects throughout the testing session and implications on rehabilitation potential.

Patients with visual deficits after stroke report about different constraints in daily life most likely due to variable compensatory strategies, which are difficult to differentiate in clinical routine. We present a clinical set-up which allows measurement of different compensatory head- and eye-movement-strategies and evaluating their effects on driving performance.

Simulation de conduite à la clinique: Test Visuel comportement exploratoire dans la vie quotidienne chez les patients avec des anomalies du champ visuel

Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily ...

Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal models of acute ischemic stroke allows to confirm successful arterial occlusion and exclude subarachnoid hemorrhage. Cerebral perfusion monitoring can also be used to study intracranial collateral circulation, which is emerging as a powerful determinant of stroke outcome and a possible therapeutic target. Despite a recognized role of Laser Doppler perfusion monitoring as part of the current guidelines for experimental cerebral ischemia, a number of technical difficulties exist that limit its widespread use. One of the major issues is obtaining a secure and prolonged attachment of a deep-penetration Laser Doppler probe to the animal skull. In this video, we show our optimized system for cerebral perfusion monitoring during transient middle cerebral artery occlusion by intraluminal filament in the rat. We developed in-house a simple method to obtain a custom made holder for twin-fibre (deep-penetration) Laser Doppler probes, which allow multi-site monitoring if needed. A continuous and prolonged monitoring of cerebral perfusion could easily be obtained over the intact skull.

Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in rats.

Système optimisé pour la surveillance de la perfusion cérébrale chez le rat des maladies du intraluminale occlusion de l&#39;artère cérébrale moyenne

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal ...

Permanent Cerebral Vessel Occlusion via Double Ligature and Transection

Stroke is a leading cause of death, disability, and socioeconomic loss worldwide. The majority of all strokes result from an interruption in blood flow (ischemia) 1. Middle cerebral artery (MCA) delivers a great majority of blood to the lateral surface of the cortex 2, is the most common site of human stroke 3, and ischemia within its territory can result in extensive dysfunction or death 1,4,5. Survivors of ischemic stroke often suffer loss or disruption of motor capabilities, sensory deficits, and infarct. In an effort to capture these key characteristics of stroke, and thereby develop effective treatment, a great deal of emphasis is placed upon animal models of ischemia in MCA.
Here we present a method of permanently occluding a cortical surface blood vessel. We will present this method using an example of a relevant vessel occlusion that models the most common type, location, and outcome of human stroke, permanent middle cerebral artery occlusion (pMCAO). In this model, we surgically expose MCA in the adult rat and subsequently occlude via double ligature and transection of the vessel. This pMCAO blocks the proximal cortical branch of MCA, causing ischemia in all of MCA cortical territory, a large portion of the cortex. This method of occlusion can also be used to occlude more distal portions of cortical vessels in order to achieve more focal ischemia targeting a smaller region of cortex. The primary disadvantages of pMCAO are that the surgical procedure is somewhat invasive as a small craniotomy is required to access MCA, though this results in minimal tissue damage. The primary advantages of this model, however, are: the site of occlusion is well defined, the degree of blood flow reduction is consistent, functional and neurological impairment occurs rapidly, infarct size is consistent, and the high rate of survival allows for long-term chronic assessment.

Permanent Cerebral Vessel Occlusion via Double Ligature and Transection

We describe a highly reproducible method for the permanent occlusion of a rodent major cerebral blood vessel. This technique can be accomplished with very little peripheral damage, minimal blood loss, a high rate of long-term survival, and consistent infarct volume commensurate with the human clinical population.

Permanent occlusion des vaisseaux cérébraux<em&gt; Via</em&gt; Double ligature et Transection

Stroke is a leading cause of death, disability, and socioeconomic loss worldwide. The majority of all strokes result from an interruption in blood flow ...

Generation and 3-Dimensional Quantitation of Arterial Lesions in Mice Using Optical Projection Tomography

The generation and analysis of vascular lesions in appropriate animal models is a cornerstone of research into cardiovascular disease, generating important information on the pathogenesis of lesion formation and the action of novel therapies. Use of atherosclerosis-prone mice, surgical methods of lesion induction, and dietary modification has dramatically improved understanding of the mechanisms that contribute to disease development and the potential of new treatments.
Classically, analysis of lesions is performed ex vivo using 2-dimensional histological techniques. This article describes application of optical projection tomography (OPT) to 3-dimensional quantitation of arterial lesions. As this technique is non-destructive, it can be used as an adjunct to standard histological and immunohistochemical analyses.
Neointimal lesions were induced by wire-insertion or ligation of the mouse femoral artery whilst atherosclerotic lesions were generated by administration of an atherogenic diet to apoE-deficient mice.
Lesions were examined using OPT imaging of autofluorescent emission followed by complementary histological and immunohistochemical analysis. OPT clearly distinguished lesions from the underlying vascular wall. Lesion size was calculated in 2-dimensional sections using planimetry, enabling calculation of lesion volume and maximal cross-sectional area. Data generated using OPT were consistent with measurements obtained using histology, confirming the accuracy of the technique and its potential as a complement (rather than alternative) to traditional methods of analysis.
This work demonstrates the potential of OPT for imaging atherosclerotic and neointimal lesions. It provides a rapid, much needed ex vivo technique for the routine 3-dimensional quantification of vascular remodelling.

Ex vivo analysis of arterial lesions from animal models of cardiovascular disease classically relies on histological and immunohistochemical techniques. These provide 2-dimensional measurements in 3-dimensional lesions. This manuscript describes the generation of arterial lesions for quantitative analysis in 3-dimensions using optical projection tomography.

Génération et quantification 3-Dimensional des lésions artérielles chez la souris utilisant la tomographie optique de projection

The generation and analysis of vascular lesions in appropriate animal models is a cornerstone of research into cardiovascular disease, generating ...

Quantitative Analysis and Characterization of Atherosclerotic Lesions in the Murine Aortic Sinus

Atherosclerosis is a disease of the large arteries and a major underlying cause of myocardial infarction and stroke. Several different mouse models have been developed to facilitate the study of the molecular and cellular pathophysiology of this disease. In this manuscript we describe specific techniques for the quantification and characterization of atherosclerotic lesions in the murine aortic sinus and ascending aorta. The advantage of this procedure is that it provides an accurate measurement of the cross-sectional area and total volume of the lesion, which can be used to compare atherosclerotic progression across different treatment groups. This is possible through the use of the valve leaflets as an anatomical landmark, together with careful adjustment of the sectioning angle. We also describe basic staining methods that can be used to begin to characterize atherosclerotic progression. These can be further modified to investigate antigens of specific interest to the researcher. The described techniques are generally applicable to a wide variety of existing and newly created dietary and genetically-induced models of atherogenesis.

We describe procedures to quantify and characterize atherosclerotic lesions in mouse models using precision sectioning of the aortic sinus and ascending aorta combined with histochemical and immunohistochemical analysis.

Analyse quantitative et caractérisation des lésions d&#39;athérosclérose dans le murin aortique Sinus

Atherosclerosis is a disease of the large arteries and a major underlying cause of myocardial infarction and stroke. Several different mouse models have ...

Dynamic Visual Tests to Identify and Quantify Visual Damage and Repair Following Demyelination in Optic Neuritis Patients

In order to follow optic neuritis patients and evaluate the effectiveness of their treatment, a handy, accurate and quantifiable tool is required to assess changes in myelination at the central nervous system (CNS). However, standard measurements, including routine visual tests and MRI scans, are not sensitive enough for this purpose. We present two visual tests addressing dynamic monocular and binocular functions which may closely associate with the extent of myelination along visual pathways. These include Object From Motion (OFM) extraction and Time-constrained stereo protocols. In the OFM test, an array of dots compose an object, by moving the dots within the image rightward while moving the dots outside the image leftward or vice versa. The dot pattern generates a camouflaged object that cannot be detected when the dots are stationary or moving as a whole. Importantly, object recognition is critically dependent on motion perception. In the Time-constrained Stereo protocol, spatially disparate images are presented for a limited length of time, challenging binocular 3-dimensional integration in time. Both tests are appropriate for clinical usage and provide a simple, yet powerful, way to identify and quantify processes of demyelination and remyelination along visual pathways. These protocols may be efficient to diagnose and follow optic neuritis and multiple sclerosis patients.
In the diagnostic process, these protocols may reveal visual deficits that cannot be identified via current standard visual measurements. Moreover, these protocols sensitively identify the basis of the currently unexplained continued visual complaints of patients following recovery of visual acuity. In the longitudinal follow up course, the protocols can be used as a sensitive marker of demyelinating and remyelinating processes along time. These protocols may therefore be used to evaluate the efficacy of current and evolving therapeutic strategies, targeting myelination of the CNS.

Object From Motion (OFM) and Time-constrained stereo protocols are sensitive tools to identify monocular and binocular dynamic visual function deficits, which are uniquely affected in optic neuritis patients. Furthermore, these tests may be used as quantitative noninvasive tools to assess the extent of myelination along visual pathways.

Tests visuels dynamiques pour identifier et quantifier les dommages visuels et de réparation suite de démyélinisation dans la névrite optique patients

In order to follow optic neuritis patients and evaluate the effectiveness of their treatment, a handy, accurate and quantifiable tool is required to ...

A Versatile Murine Model of Subcortical White Matter Stroke for the Study of Axonal Degeneration and White Matter Neurobiology

Stroke affecting white matter accounts for up to 25% of clinical stroke presentations, occurs silently at rates that may be 5-10 fold greater, and contributes significantly to the development of vascular dementia. Few models of focal white matter stroke exist and this lack of appropriate models has hampered understanding of the neurobiologic mechanisms involved in injury response and repair after this type of stroke. The main limitation of other subcortical stroke models is that they do not focally restrict the infarct to the white matter or have primarily been validated in non-murine species. This limits the ability to apply the wide variety of murine research tools to study the neurobiology of white matter stroke. Here we present a methodology for the reliable production of a focal stroke in murine white matter using a local injection of an irreversible eNOS inhibitor. We also present several variations on the general protocol including two unique stereotactic variations, retrograde neuronal tracing, as well as fresh tissue labeling and dissection that greatly expand the potential applications of this technique. These variations allow for multiple approaches to analyze the neurobiologic effects of this common and understudied form of stroke.

Here we present methodology for the production of a focal stroke in murine white matter by local injection of an irreversible endothelial nitric oxide synthase (eNOS) inhibitor (L-Nio). Presented are two stereotactic variations, retrograde neuronal tracing, and fresh tissue labeling and dissection that expand the potential applications of this technique.

A Stroke Versatile modèle murin de Subcortical substance blanche pour l&#39;étude de axonale Degeneration et blanc Matière Neurobiologie

Stroke affecting white matter accounts for up to 25% of clinical stroke presentations, occurs silently at rates that may be 5-10 fold greater, and ...

Autologous Microfractured and Purified Adipose Tissue for Arthroscopic Management of Osteochondral Lesions of the Talus

In recent years, regenerative techniques have been increasingly studied and used to treat osteochondral lesions of the talus. In particular, several studies have focused their attention on mesenchymal stem cells derived from adipose tissue. Adipose-derived stem cells (ADSCs) exhibit morphological characteristics and properties similar to other mesenchymal cells, and are able to differentiate into several cellular lines. Moreover, these cells are also widely available in the subcutaneous tissue, representing 10 - 30% of the normal body weight, with a concentration of 5,000 cells per gram of tissue.
In the presented technique, the first step involves harvesting ADSCs from the abdomen and a process of microfracture and purification; next, the surgical procedure is performed entirely arthroscopically, with less soft tissue dissection, better joint visualization, and a faster recovery compared with standard open procedures. Arthroscopy is characterized by a first phase in which the lesion is identified, isolated, and prepared with microperforations; the second step, performed dry, involves injection of adipose tissue at the level of the lesion.
Between January 2016 and September 2016, four patients underwent arthroscopic treatment of osteochondral lesion of the talus with microfractured and purified adipose tissue. All patients reported clinical improvement six months after surgery with no reported complications. Functional scores at the latest follow-up are encouraging and confirm that the technique provides reliable pain relief and improvements in patients with osteochondral lesion of the talus.

The aim of this study is to report a protocol for the arthroscopic treatment of osteochondral lesions of the talus using microfractured and purified adipose-derived stem cells.

Microfractured autologue et purifiée du tissu adipeux pour gestion arthroscopique des lésions cartilagineuses de l’astragale

In recent years, regenerative techniques have been increasingly studied and used to treat osteochondral lesions of the talus. In particular, several ...

Assessment of Static Graviceptive Perception in the Roll-Plane using the Subjective Visual Vertical Paradigm

Vestibular disorders are among the most common syndromes in medicine. In recent years, new vestibular diagnostic systems have been introduced that allow the examination of all semicircular canals in the clinical setting. Assessment methods of the otolithic system, which is responsible for the perception of linear acceleration and perception of gravity, are far less in clinical use. There are several experimental approaches for measuring the perception of gravity. The most frequently used method is the determination of the subjective visual vertical. This is usually measured with the head in an upright position. We present here an assessment method for testing otolith function in the roll plane. The subjective visual vertical is measured in the head upright position as well as with head inclination of &#177; 15&#176; and &#177; 30&#176; in the roll plane. This extended functional paradigm is an easy-to-perform clinical test of otolith function and ensures increased information content for the detection of impaired graviceptive perception.

The perception of gravity is commonly determined by the subjective visual vertical in the head upright position. The additional assessment at head tilts of &#177; 15&#176; and &#177; 30&#176; in the roll plane ensures increased information content for the detection of impaired graviceptive perception.

Évaluation de la perception graviceptive statique dans le roll-Plane à l’aide du paradigme vertical visuel subjectif

Vestibular disorders are among the most common syndromes in medicine. In recent years, new vestibular diagnostic systems have been introduced that allow ...