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

NOTA: Este protocolo sigue las directrices del Centro Hospitalario de Luxemburgo en Luxemburgo. 1 Preparación de Difusión Tensor Imaging para la vía visual para Neurocirugía y Seguimiento <ol style="margin-left: 40px;"><li> Realice una operación de imagen de resonancia magnética al menos un día antes de la cirugía estrictamente axial utilizando 32 direcciones de gradiente y una b0-imagen. Mantener un estrecho contacto con la unidad de neurorradiología en cualquier momento. NOTA: Dejar claro a la neuro-radiólogo que las imágenes después de la cirugía son los mismos que los de antes de la operación. </li><li> El uso de un 3-Tesla MRI, realice unas exploraciones ponderados 3DT1 y DTI-secuencia. Lleve a cabo una secuencia ponderada 3DT1 después de la cirugía también. </li></ol> 2. Uso de la estación de Planificación <ol><li> La transferencia de los datos de exploración en T2, ponderado 3DT1 y DTI-secuencia de imágenes digitales y comunicaciones en medicina (DICOM). Este procedimiento tarda hasta 7 min. NOTA: Don `t detener el procedimiento before haber transferido todas las secuencias. Es posible detener y continuar más tarde en función de la fecha de la cirugía. </li><li> Abra el programa del sistema de navegación quirúrgica. Haga clic en Archivo y luego en Importar DICOM. Repita este procedimiento tres veces para todas las secuencias mencionadas anteriormente. <ol><li> Haga clic en Agregar para ver. Añadir cada secuencia por separado. Don `t tratar de proceder con Vista. </li></ol></li><li> Haga clic en Herramientas. Abrir preparación DTI Tensor. Observar una nueva ventana en el centro de la pantalla. </li><li> Complete los siguientes cuatro pasos. <ol><li> Realizar Asignación degradado como el primer paso. <ol><li> Cambie el valor b de 1.000 a 800 s / mm en la parte inferior derecha de la ventana. </li><li> Ajuste el umbral en la parte superior derecha de la ventana. Hacerlo manualmente simplemente escribiendo un número o mover un cursor. 20 podría ser un valor aceptable. Es una experiencia personal y no es obligatorio. </li></ol></li><li> Realice Registro Gradiente como el segundo paso. <ol> &lt;li&gt; Haga clic en el botón All Auto. Este procedimiento tarda hasta 5 min. </li><li> Haga clic en Verificar todos los registros. Sin verificar los registros no es posible continuar. </li></ol></li><li> Realizar Coregistro como el tercer paso. <ol><li> Coregister MR1 y MR2 b0 imágenes manualmente. Al final Verifique todos los registros. NOTA: Es posible realizar este paso automáticamente. Sin embargo, los resultados pueden no ser siempre satisfactorio al final. </li></ol></li><li> Realizar Tensor de cálculo como el cuarto y último paso, <ol><li> Asegúrese de FA / DEC / ADC están encendidas. Si no, haga clic en ON. </li><li> Haga clic en Calcular. Este procedimiento se llevará sólo unos segundos. </li></ol></li></ol></li><li> Guarde todos los datos y continuar con fibertracking. No deje sin guardar todo. </li></ol> 3. Fibertracking NOTA: Anatomic conocimiento de la vía visual es muy importante para el resultado exitoso. <ol style = &quot;margin-left: 40px;&quot;&gt; <li> Prepárese para encontrar los tres puntos importantes en los que las fibras tienen que pasar. </li><li> Determinar el quiasma óptico utilizando conocimientos anatómicos. <ol><li> Utilice un retorno de la inversión como punto de partida y dejar que las fibras atraviesan. ROIs se definen por el médico. </li><li> Alternativamente, el segmento de la región sospechosa. Haga clic en la segmentación en la parte inferior izquierda y aparecerá otra ventana. Zonas segmentadas son anatómicamente áreas definidas. <ol><li> Pinte la región manualmente. Desplácese hacia arriba y hacia abajo para incluir todo el quiasma óptico. Guarde el procedimiento y volver. </li></ol></li><li> Seguimiento de las fibras, ya sea de la región de interés o de la zona segmentada o ambos. </li><li> Las fibras llegan al núcleo geniculado izquierda (LGN), que es el segundo punto importante de la vía visual. El ángulo máximo era 50. El riesgo de falsos tractos se levantará con si el ángulo es demasiado alto. <ol><li> Existe la posibilidad de segmentar el LGN como se muestra con el quiasma ópticoy luego rastrear las fibras. Después de haber segmentado el quiasma óptico, fibras de pistas que discurren desde el LGN y terminar en el quiasma óptico o viceversa. </li></ol></li><li> Segmento de la corteza visual. Proceder como en el caso del quiasma óptico. Esto puede llevar algún tiempo como imagen ponderada 3DT1 contiene 160 rebanadas. </li><li> Seguimiento de las fibras de la corteza visual del LGN. Es posible realizar un seguimiento de ellos desde el LGN a la corteza visual. </li><li> Si la corteza visual es invadido por un tumor o edema luego usar una región de interés en lugar de un espacio segmentado y luego dejar que las fibras corren en dirección del LGN. NOTA: Si el edema se segmenta a veces podría invadir la corteza visual a continuación, a continuación, la corteza visual no podría ser capaz de segmentar por completo porque el equipo `t distinguir entre ellos. That `s por eso que es necesario poner un retorno de la inversión. </li><li> Repetir todo para el otro hemisferio. </li><li> Comience con el hemisferio sano primero. NOTA: Sees posible empezar con el otro también, pero podría ser más fácil de rastrear las fibras del hemisferio sano primero en convertirse en una primera idea acerca de la situación. No es obligatorio, es sólo un consejo. </li></ol></li><li> Segmento de la lesión cerebral y el edema. Proceda como se mencionó anteriormente en el punto 3.2.2. <ol><li> Asignar un color para cada área segmentada o la lesión a fin de distinguir mejor. </li></ol></li><li> Guarde el procedimiento después de cada paso en caso de acontecimientos imprevistos o en caso de una emergencia. </li><li> Exportar todos los datos a nivel local. Es posible exportar a la sala de operaciones directamente pero `t del isn recomienda. <ol><li> Pulse Archivo y luego Exportar objetos 3D. Asegúrese de exportar sólo el Examen de navegación. </li><li> Don `t exportar el Examen híbrido. </li></ol></li><li> Ingrese craneal. Elija el paciente adecuado a continuación, pulse Stealthmerge. Seleccione las imágenes potenciadas en 3DT1 como examen de referencia. </li><li> Crear un modelo 3D e insertar todo. </li><li> Importe el i datosn la sala de operaciones. </li></ol>

<ol>
	<li>Fernandez-Miranda, J. 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=High-Definition+Fiber+Tractography+of+the+Human+Brain:+Neuroanatomical+Validation+and+Neurosurgical+Applications.">High-Definition Fiber Tractography of the Human Brain: Neuroanatomical Validation and Neurosurgical Applications.</a> Neurosurgery. 71 (2), 430-453 (2012).</li><li>Alexander, D. C., Barker, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimal+imaging+parameters+for+fiber-orientation+estimation+in+diffusion+MRI.">Optimal imaging parameters for fiber-orientation estimation in diffusion MRI.</a> Neuroimage. 27 (2), 357-367 (2005).</li><li>Le Bihan, D., Poupon, C., Amadon, A., Lethimonnier, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Artifacts+and+pitfalls+in+diffusion+MRI.">Artifacts and pitfalls in diffusion MRI.</a> J Magn Reson Imaging. 24 (3), 478-488 (2006).</li><li>Abdullah, K. G., Lubelski, D., Nucifora, P. G., Brem, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+diffusion+tensor+imaging+in+glioma+resection.">Use of diffusion tensor imaging in glioma resection.</a> Neurosurg Focus. 34 (4), (2013).</li><li>Ota, T., Kawai, K., Kamada, K., Kin, T., Saito, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+monitoring+of+cortically+recorded+visual+response+for+posterior+visual+pathway.">Intraoperative monitoring of cortically recorded visual response for posterior visual pathway.</a> J Neurosurg. 112, 285-294 (2010).</li><li>Gras-Combe, G., Moritz-Gasser, S., Herbet, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+subcortical+electrical+mapping+of+optic+radiations+in+awake+surgery+for+glioma+involving+visual+pathways.">Intraoperative subcortical electrical mapping of optic radiations in awake surgery for glioma involving visual pathways.</a> J Neurosurg. 117 (3), 466-473 (2012).</li><li>Maruyama, 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=Optic+radiation+tractography+integrated+into+simulated+treatment+planning+for+Gamma+Knife+surgery.">Optic radiation tractography integrated into simulated treatment planning for Gamma Knife surgery.</a> J Neurosurg. 107, 721-726 (2007).</li><li>Bérubé, J., McLaughlin, N., Bourgouin, P., Beaudoin, G., Bojanowski, M. W. <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+imaging+analysis+of+long+association+bundles+in+the+presence+of+an+arteriovenous+malformation.">Diffusion tensor imaging analysis of long association bundles in the presence of an arteriovenous malformation.</a> J Neurosurg. 107 (3), 509-514 (2007).</li><li>Sun, G. 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. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+and+modeling+of+non-Gaussian+apparent+diffusion+coefficient+profiles+in+human+brain+data.">Detection and modeling of non-Gaussian apparent diffusion coefficient profiles in human brain data.</a> Magn Reson Med. 48 (2), 331-340 (2002).</li><li>Mori, S., Crain, B. J., Chacko, V. P., 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=Three-dimensional+tracking+of+axonal+projections+in+the+brain+by+magnetic+resonance+imaging.">Three-dimensional tracking of axonal projections in the brain by magnetic resonance imaging.</a> Ann Neurol. 45, 265-269 (1999).</li><li>Conturo, 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=Tracking+neuronal+fiber+pathways+in+the+living+human+brain.">Tracking neuronal fiber pathways in the living human brain.</a> Proc Natl Acad Sci U S A. 96, 10422-10427 (1999).</li><li>Poupon, 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=Regularization+of+diffusion-based+direction+maps+for+the+tracking+of+brain+white+matter+fascicles.">Regularization of diffusion-based direction maps for the tracking of brain white matter fascicles.</a> Neuroimage. 12, 184-195 (2000).</li><li>Parker, G. J., Haroon, H. A., Wheeler-Kingshott, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+framework+for+a+streamline-based+probabilistic+index+of+connectivity+(PICo)+using+a+structural+interpretation+of+MRI+diffusion+measurements.">A framework for a streamline-based probabilistic index of connectivity (PICo) using a structural interpretation of MRI diffusion measurements.</a> J Magn Reson Imaging. 18, 242-254 (2003).</li><li>Behrens, T. E., 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=Non-invasive+mapping+of+connections+between+human+thalamus+and+cortex+using+diffusion+imaging.">Non-invasive mapping of connections between human thalamus and cortex using diffusion imaging.</a> Nat Neurosci. 6, 750-757 (2003).</li><li>Reinges, M. H., Schoth, F., Coenen, V. A., Krings, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+of+postthalamic+visual+fiber+tracts+by+anisotropic+diffusion+weighted+MRI+and+diffusion+tensor+imaging:+principles+and+applications.">Imaging of postthalamic visual fiber tracts by anisotropic diffusion weighted MRI and diffusion tensor imaging: principles and applications.</a> European Journal of Radiology. 49, 91-104 (2004).</li><li>Sherbondy, A. J., Dougherty, R. F., Napel, S., Wandell, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identifying+the+human+optic+radiation+using+diffusion+imaging+and+fiber.">Identifying the human optic radiation using diffusion imaging and fiber.</a> J. Vis. 8 (10), (2008).</li></ol>

The authors declare that they have no competing financial interests.

DTI es una técnica que permite al neurocirujano para visualizar tractos de sustancia blanca en vivo 8. La vía visual es una de estas extensiones. Aunque este método proporciona a los médicos nuevas posibilidades en materia de tratamiento de los pacientes con lesiones en relación con las regiones elocuentes del cerebro que tenemos que decir que algunas limitaciones de esta técnica hacen todavía existen. El primero y más obvio desafío es el cambio del cerebro, que sigue siendo un problema bajo...

Imágenes de tensor de difusión (DTI) se utiliza para retratar WMT no invasiva en el cerebro humano 1. Se ha utilizado en la última década para reducir el riesgo de dañar áreas elocuentes del cerebro durante la cirugía 1. DTI se realizó en cincuenta pacientes entre marzo de 2012 y enero de 2014 para retratar la vía visual. DTI puede mejorar la preservación de áreas elocuentes del cerebro durante la cirugía, proporcionando información importante acerca de la localización anatómica de los tractos de sustancia blanca. Se ha incorporado en la planificación estratégica para la resección de las lesiones cerebrales complejas 1. Sin embargo, la representación de la vía visual sigue siendo un reto, porque no existe un estándar para los parámetros de DTI, la colocación de los volúmenes de semillas y la interpretación de los resultados 12. Diferentes algoritmos se han aplicado hasta la fecha 19-21. Algunos enfoques se concentran en métodos deterministas 19, 22-25. Otros estaban utilizando métodos probabilísticos, 26,27,29. Más recientemente, las técnicas que utilizan campos tensoriales Q-ball, la imagen espectral de difusión y de alta resolución angular Difusión Imaging (HARDI) están siendo utilizados para representar tractos de sustancia blanca entre otros la vía visual 1,13-15,18. Sin embargo, el tiempo necesario para HARDI es significativamente más larga con 45 min, el software no está disponible comercialmente y hace hincapié en aplicaciones científicas 18. El período de enseñanza para HARDI parece ser más largo que para DTI 18. El protocolo presentado es fácil factible y puede ser utilizado para la rutina diaria en las operaciones de neurocirugía con el fin de evitar la morbilidad y mejorar el resultado postoperatorio. El tiempo adicional para este protocolo es menos de 9 minutos, que es significativamente más rápido que otros protocolos 1,9,12,16. Reconociendo el hecho de que muchos algoritmos sofisticados se han desarrollado recientemente los restringe de papelen sí con el uso de un software comercialmente disponible y aprobado por la FDA. Sin embargo, es obligatorio tener en cuenta las limitaciones de esta técnica que se ha mencionado anteriormente.

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</table>

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

<html> DTI es una técnica que identifica tractos de sustancia blanca (WMT) de forma no invasiva en pacientes sanos y no sanos utilizando mediciones de difusión. Al igual que en las vías visuales (VP), WMT no son visibles con la RM clásica o dentro de la cirugía con el microscopio. DIT ayudará neurocirujanos para evitar la destrucción de la VP, mientras que la eliminación de lesiones adyacentes a esta WMT. Hemos realizado DTI en cincuenta pacientes antes y después de la cirugía, entre marzo de 2012 hasta enero de 2014 Para navegar se utilizó una secuencia ponderada 3DT1. Adicionalmente, se realizó un T2 y DTI-secuencias. Los parámetros utilizados fueron, FOV: 200 x 200 mm, espesor de corte: 2 mm, y matriz de adquisición: 96 x 96 voxels rendimiento casi isotrópica de 2 x 2 x 2 mm. Axial MRI se llevó a cabo utilizando un gradiente de dirección 32 y una b0-imagen. Utilizamos Echo-Planar-Imaging (EPI) e imágenes en paralelo ASSET con un factor de aceleración de 2 y b-valor de 800 s / mm ². El tiempo de exploración fue de menos de 9 min. ent &quot;&gt; Los-datos DTI obtenidos fueron procesados ​​mediante un FDA aprobó el programa del sistema de navegación quirúrgico que utiliza un enfoque directo de fibra de seguimiento conocido como asignación de fibra mediante el seguimiento continuo (FACT). Esto se basa en la propagación de las líneas entre las regiones de interés ( ROI) que se define por un médico. un ángulo máximo de 50, FA valor inicial de 0,10 y ADC valor de parada de 0,20 mm ² / s fueron los parámetros utilizados para tractography. Hay algunas limitaciones a esta técnica. El marco de tiempo de adquisición limitada hace cumplir las compensaciones en la calidad de la imagen. Otro punto importante no descuidar es el cambio del cerebro durante la cirugía. En cuanto a esta última resonancia magnética intraoperatoria puede ser útil. Además, el riesgo de falsos tractos positivos o falsos negativos se debe tener en cuenta que podría comprometer los resultados finales.

<html> Este protocolo permite al médico adecuado para retratar las principales partes de la VP. Se puede utilizar con una pequeña cantidad de tiempo a fin de evitar daños en los pacientes con lesiones cerebrales próximos a las áreas elocuentes. Controles postoperatorios muestran también buenos resultados. VP es representado en la figura 7 después de que el paciente fue operado de un glioblastoma. Figura 2 muestra la VP después de la recurrencia de un glioblastoma. Los autores rec...

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

Imágenes de tensor de difusión (DTI) se llevó a cabo para tratar de representar las principales partes de la vía visual. El objetivo era utilizar una estación de trabajo aprobado por la FDA comercial estándar que se podría utilizar para la rutina diaria con el fin de tratar de reducir el daño postoperatorio de la vía visual en los pacientes.

DTI de la vía visual - la sustancia blanca Tracts y lesiones cerebrales

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

Research

JoVE Journal

Medicine

13.9K vistas.  Centre Hospitalier de Luxembourg.  Imágenes de tensor de difusión (DTI) se llevó a cabo para tratar de representar las principales partes de la vía visual. El objetivo era utilizar una estación de trabajo aprobado por la FDA comercial estándar que se podría utilizar para la rutina diaria con el fin de tratar de reducir el daño postoperatorio de la vía visual en los pacientes. 

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

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.

La aplicación de la Permanente Ligadura arteria cerebral media en el ratón

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 ...

Investigación

Medicina

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.

Simulación de conducción en la clínica: Pruebas de Comportamiento Visual exploratoria en las Actividades de la vida diaria en pacientes con defectos del campo visual

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.

Sistema optimizado para la monitorización de la perfusión cerebral en el modelo de rata de Carrera intraluminal oclusión arteria cerebral media

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.

Permanente oclusión vascular cerebral<em&gt; Vía</em&gt; Ligadura doble y transección

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.

Generación y cuantificación de 3 dimensiones de las lesiones arteriales en ratones mediante tomografía óptica de proyección

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.

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 visuales dinámicos para identificar y cuantificar los daños visuales y Reparación Siguiendo desmielinización en neuritis óptica pacientes

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.

Un movimiento versátil modelo murino de la sustancia blanca subcortical para el Estudio de la degeneración axonal y la sustancia blanca Neurobiología

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 autólogo y purificada del tejido adiposo para manejo artroscópico de las lesiones osteocondrales de astrágalo

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.

Evaluación de la percepción gravocetiva estática en el roll-plane utilizando el paradigma vertical visual subjetivo

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