Tractography to Depict Three Layers of Visual Field Trajectories to the Calcarine Gyri

Yamamoto, Takara; Yamada, Kazuo; Nishimura, Tsunehiko; Kinoshita, Shigeru

doi:10.1016/j.ajo.2005.05.018

Cited by 87 publications

(91 citation statements)

References 28 publications

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“…The overall distance between ML-TP in this study is 42.9 mm, which is comparable to measurements reported by Nilsson et al (2007Nilsson et al ( , 2010 and Wu et al (2012) (40.2mm) M a n u s c r i p t using deterministic tractography. However, these measurements are high in contrast to other deterministic tractography studies that report ML-TP distances that are ≤ 37.3 mm (Chen et al, 2009;Taoka et al, 2008;Yamamoto et al, 2005, Yogarajah et al, 2009; for review see Mandelstam 2012). Indeed, streamline algorithms have been criticised due to their high false negative rate (Mandelstam 2012;Sherbondy et al, 2008).…”

Section: Distance Measurementsmentioning

confidence: 93%

“…Although there are a number of dissection studies (Burgel et al, 1999;Ebeling and Reulen 1988;Kier et al, 2004;Rubino et al, 2005;Sincoff et al, 2004) and tractography (Chen et al, 2009;Choi et al, 2006;Nilsson et al, 2007Nilsson et al, , 2010Sherbondy et al, 2008;Taoka et al, 2008;Yamamoto et al, 2005Yamamoto et al, , 2007Yogarajah et al, 2009;Wang et al, 2010;Winston et al, 2012) that have explored the anatomy of ML, there is considerable variability in reports of the exact location, trajectory, volume and hemispheric asymmetry of the tract. For example, in dissection studies the distance of the most anterior extent of ML to the temporal pole (ML-TP) is usually shorter compared M a n u s c r i p t to tractography studies.…”

Section: Introductionmentioning

confidence: 99%

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Tractography of Meyer's Loop asymmetries

et al. 2014

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Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Tractography of meyer's loop asymmetries NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21272153&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21272153&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions?Contact the NRC Publications Archive team at PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://doi.org/10.1016/j.eplepsyres.2014.03.006Epilepsy Research, 108, 5, pp. 872-882, 2014 Accepted Manuscript This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A c c e p t e d M a n u s c r i p t ABSTRACT Purpose:The purpose of the current study was to use diffusion tensor imaging (DTI) to conduct tractography of the optic radiations (OR) and its component bundles and to assess both the degree of hemispheric asymmetry and the inter-subject variability ofMeyer's Loop (ML). We hypothesized that there are significant left versus right differences in the anterior extent of ML to the temporal pole (TP) in healthy subjects.Materials and Methods: DTI data were acquired on a 3T Siemens MRI system using a single-shot Spin Echo EPI sequence. The dorsal, central and ML bundles of the OR were tracked and visualized in forty hemispheres of twenty healthy volunteers. The uncinate fasciculus (UF) was also tracked in these subjects so that it could be used as a distinct anatomical reference. Measurements were derived for the distance between ML-TP, ML and the temporal horn (ML-TH) and ML and...

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Section: Distance Measurementsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Tractography of Meyer's Loop asymmetries

et al. 2014

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“…Many investigators used DTT to reconstruct and identify the course of the optic radiation by manually choosing two ROIs in the lateral geniculate body and the calcarine cortex respectively, technique that reconstructs exclusively the optic radiation fibers and does not consider the complex network or neighboring projection fibers in the region of the lateral geniculate body [11,21,24,27]. The Meyer's loop reconstructed in these studies might be an overestimation of the actual structure, because of the increase probability of including the dense network of projection fibers intermingled with the optic radiation in the region of the lateral geniculate body.…”

Section: Discussionmentioning

confidence: 99%

“…Then, an exhaustive search was performed to identify all the fibers that penetrate both ROIs and participate in the formation of Meyer's loop, and then parcelate these fibers according to their different connections. By using large ROIs instead of directly defining ROIs in the lateral geniculate body and the calcarine visual cortex that were assumed by classical DTI studies to exclusively reconstruct visual projection fibers [11,21,[24][25][26], we hypothesized that our technique should be more accurate in estimating the composition of the Meyer's loop because of the following considerations. First, both histological and fiber dissection studies have shown that the lateral geniculate body was surrounded by a dense and intricate network of projection fibers among which the visual projection fibers are only one of the various components, so seeding in the region of the lateral geniculate body, including the pulvinar and crus cerebri, has the possibility of including these neighboring projection fibers and we could check whether these projection fibers pass through the Meyer's loop, to ensure that all components of the Meyer's loop are reconstructed and not exclusively the optic radiation fibers [1][2][3].…”

Section: Methodsmentioning

confidence: 99%

“…The DTT is generated using mathematical algorithms that connect image voxels based on their anisotropy and principal diffusion direction [6,[8][9][10]. Because DTT offers the only currently available method for a noninvasive investigation of the white matter fibers, it might provide additional data regarding the anatomy of the Meyer's loop [11][12][13][14][15][16].…”

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confidence: 99%

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Meyer’s Loop Anatomy Demonstrated Using Diffusion Tensor MR Imaging and Fiber Tractography at 3T

Goga

Fırat

Brînzaniuc

et al. 2014

Acta Medica Marisiensis

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Objective: The ultimate anatomy of the Meyer's loop continues to elude us. Diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) may be able to demonstrate, in vivo, the anatomy of the complex network of white matter fibers surrounding the Meyer's loop and the optic radiations. This study aims at exploring the anatomy of the Meyer's loop by using DTI and fiber tractography. Methods: Ten healthy subjects underwent magnetic resonance imaging (MRI) with DTI at 3 T. Using a region-of-interest (ROI) based diffusion tensor imaging and fiber tracking software (Release 2.6, Achieva, Philips), sequential ROI were placed to reconstruct visual fibers and neighboring projection fibers involved in the formation of Meyer's loop. The 3-dimensional (3D) reconstructed fibers were visualized by superimposition on 3-planar MRI brain images to enhance their precise anatomical localization and relationship with other anatomical structures. Results: Several projection fiber including the optic radiation, occipitopontine/parietopontine fibers and posterior thalamic peduncle participated in the formation of Meyer's loop. Two patterns of angulation of the Meyer's loop were found. Conclusions: DTI with DTT provides a complimentary, in vivo, method to study the details of the anatomy of the Meyer's loop. Meyer's loop is commonly known as the temporal loop of the anterior fibers of the optic radiation that originate in the lateral geniculate body and course anteriorly, into the temporal lobe, before turning posteriorly to reach the occipital visual cortex. Adolf Meyer applied histological, brain lesion studies to describe this peculiar course into the temporal lobe of the visual projection fibers, in 1907 [1]. Histological staining techniques that are applicable in humans provide an ambiguous visualization of the myelinstained white matter fibers and are limited by an inability to precisely trace and reconstruct the course of these fibers. Therefore, the composition and course of the Meyer's loop, or the fact that this temporal loop is composed exclusively by the optic radiation fibers remains unclear.A unique 3D perspective on the white matter architecture can be achieved by applying the fiber dissection technique, but with this technique it is difficult to differentiate individual visual projection fibers, because of the intrinsic limitations of this technique to distinguish and trace individual fibers among the complex network of many neighboring fibers [2,3]. Furthermore, the delineation of the Meyer's loop using the fiber dissection technique is challenging and its exact fiber composition and location are a point of controversy. Knowledge of the anatomy of the Meyer's loop is essential for minimizing the risk of damaging this structure during surgery for temporal lobe lesions and epilepsy. However, the ultimate anatomical details of the Meyer's loop remain even today obscure, because both histological and fiber dissection techniques are less suitable to accurately demonstrate its precise fiber composition and exact lo...

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