| 1. |
- Latini, Francesco, 1982-, et al.
(författare)
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Segmentation of the inferior longitudinal fasciculus in the human brain : A white matter dissection and diffusion tensor tractography study
- 2017
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Ingår i: Brain Research. - : Elsevier. - 0006-8993 .- 1872-6240. ; 1675, s. 102-115
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Tidskriftsartikel (refereegranskat)abstract
- The inferior longitudinal fascicle (ILF) is one of the major occipital-temporal association pathways. Several studies have mapped its hierarchical segmentation to specific functions. There is, however, no consensus regarding a detailed description of ILF fibre organisation. The aim of this study was to establish whether the ILF has a constant number of subcomponents. A secondary aim was to determine the quantitative diffusion proprieties of each subcomponent and assess their anatomical trajectories and connectivity patterns. A white matter dissection of 14 post-mortem normal human hemispheres was conducted to define the course of the ILF and its subcomponents. These anatomical results were then investigated in 24 right-handed, healthy volunteers using in vivo diffusion tensor imaging (DTI) and streamline tractography. Fractional anisotropy (FA), volume, fibre length and the symmetry coefficient of each fibre group were analysed. In order to show the connectivity pattern of the ILF, we also conducted an analysis of the cortical terminations of each segment. We confirmed that the main structure of the ILF is composed of three constant components reflecting the occipital terminations: the fusiform, the lingual and the dorsolateral-occipital. ILF volume was significantly lateralised to the right. The examined indices of ILF subcomponents did not show any significant difference in lateralisation. The connectivity pattern and the quantitative distribution of ILF subcomponents suggest a pivotal role for this bundle in integrating information from highly specialised modular visual areas with activity in anterior temporal territory, which has been previously shown to be important for memory and emotions.
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| 2. |
- Latini, Francesco, et al.
(författare)
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The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection
- 2015
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Ingår i: Behavioural Neurology. - : Hindawi Limited. - 0953-4180 .- 1875-8584.
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Tidskriftsartikel (refereegranskat)abstract
- The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity.
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| 3. |
- Latini, Francesco, et al.
(författare)
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The use of a cerebral perfusion and immersion-fixation process for subsequent white matter dissection
- 2015
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Ingår i: Journal of Neuroscience Methods. - : Elsevier BV. - 0165-0270 .- 1872-678X. ; 253, s. 161-169
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Klingler's method for white matter dissection revolutionized the study of deep cerebral anatomy. Although this technique made white matter dissection more feasible and widely used, it still presents some intrinsic limitations. New method: We evaluated the quality of different methods for specimen preparation based on an intra-carotidal formalin perfusion fixation process. Ten post-mortem human hemispheres were prepared with this method and dissected in a stepwise manner. Results: The homogeneous and rapid fixation of the brain allowed documentation of several fine additional anatomical details. Intra-cortical white matter terminations were described during the first stage of dissection on each specimen. No limitations were encountered during dissection of the major associative bundles. On the contrary, the quality of the fixation of the specimens made it possible to isolate them en bloc. One of the most complex and deep bundles (accumbo-frontal fasciculus) was dissected without technical limitations. Deep vascular structures were very well preserved and dissected within the white matter until their sub-millimetric terminations. Comparison with existing method: Short time for preparation, a more homogeneous fixation, no technical limitation for a detailed description of superficial and deep white matter anatomy, the possibility to dissect with a single technique the fibre organization and the white matter vascular architecture are the advantages reported with the perfusion fixation. Conclusion: These results provide encouraging data about the possibility to use a perfusion fixation process, which may help in improving the quality of white matter dissection for research, didactic purposes and surgical training.
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| 4. |
- Basma, Jaafar, et al.
(författare)
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Minimizing Collateral Brain Injury Using a Protective Layer of Fibrin Glue : Technical Note
- 2015
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Ingår i: World Neurosurgery. - : Elsevier BV. - 1878-8750 .- 1878-8769. ; 84:6, s. 2030-2036
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neurosurgical procedures expose the brain surface to a constant risk of collateral injury. We describe a technique where the brain surface is covered with a protective layer of fibrin glue and discuss its advantages. METHODS: A thin layer of fibrin glue was applied on the brain surface after its exposure in 34 patients who underwent different craniotomies for tumoral and vascular lesions. Data of 35 more patients who underwent standard microsurgical technique were collected as a control group. Cortical and pial injuries were evaluated using an intra-operative visual scale. Eventual abnormal signals at the early postoperative T2-weighted fluid-attenuated inversion recovery (T2FLAIR) magnetic resonance imaging (MRI) sequences were evaluated in oncological patients. RESULTS: Total pial injury was noted in 63% of cases where fibrin glue was not used. In cases where fibrin glue was applied, a significantly lower percentage of 26% (P < 0.01) had pial injuries. Only 9% had injuries in areas covered with fibrin glue (P < 0.0001). Early postoperative T2FLAIR MRI confirmed the differences of altered signal around the surgical field in the two populations. CONCLUSION: We propose beside an appropriate and careful microsurgical technique the possible use of fibrin glue as alternative, safe, and helpful protection during complex microsurgical dissections. Its intrinsic features allow the neurosurgeon to minimize the cortical manipulation preventing minor collateral brain injury.
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| 5. |
- Latini, Francesco, 1982-, et al.
(författare)
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A novel radiological classification system for cerebral gliomas: The Brain-Grid.
- 2019
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Standard radiological/topographical classifications of gliomas often do not reflect the real extension of the tumor within the lobar-cortical anatomy. Furthermore, these systems do not provide information on the relationship between tumor growth and the subcortical white matter architecture. We propose the use of an anatomically standardized grid system (the Brain-Grid) to merge serial morphological magnetic resonance imaging (MRI) scans with a representative tractographic atlas. Two illustrative cases are presented to show the potential advantages of this classification system.MRI scans of 39 patients (WHO grade II and III gliomas) were analyzed with a standardized grid created by intersecting longitudinal lines on the axial, sagittal, and coronal planes. The anatomical landmarks were chosen from an average brain, spatially normalized to the Montreal Neurological Institute (MNI) space and the Talairach space. Major white matter pathways were reconstructed with a deterministic tracking algorithm on a reference atlas and analyzed using the Brain-Grid system.In all, 48 brain grid voxels (areas defined by 3 coordinates, axial (A), coronal (C), sagittal (S) and numbers from 1 to 4) were delineated in each MRI sequence and on the tractographic atlas. The number of grid voxels infiltrated was consistent, also in the MNI space. The sub-cortical insula/basal ganglia (A3-C2-S2) and the fronto-insular region (A3-C2-S1) were most frequently involved. The inferior fronto-occipital fasciculus, anterior thalamic radiation, uncinate fasciculus, and external capsule were the most frequently associated pathways in both hemispheres.The Brain-Grid based classification system provides an accurate observational tool in all patients with suspected gliomas, based on the comparison of grid voxels on a morphological MRI and segmented white matter atlas. Important biological information on tumor kinetics including extension, speed, and preferential direction of progression can be observed and even predicted with this system. This novel classification can easily be applied to both prospective and retrospective cohorts of patients and increase our comprehension of glioma behavior.
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| 6. |
- Latini, Francesco, 1982-, et al.
(författare)
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A novel radiological classification system for cerebral gliomas: The Brain-Grid. : Classification of cerebral gliomas with Brain-Grid system
- 2019
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Ingår i: PLOS ONE. - San Francisco, California, USA : Public Library of Science (PLoS). - 1932-6203. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- PurposeStandard radiological/topographical classifications of gliomas often do not reflect the real extension of the tumor within the lobar-cortical anatomy. Furthermore, these systems do not provide information on the relationship between tumor growth and the subcortical white mat- ter architecture. We propose the use of an anatomically standardized grid system (the Brain-Grid) to merge serial morphological magnetic resonance imaging (MRI) scans with a representative tractographic atlas. Two illustrative cases are presented to show the potential advantages of this classification system.MethodsMRI scans of 39 patients (WHO grade II and III gliomas) were analyzed with a standardized grid created by intersecting longitudinal lines on the axial, sagittal, and coronal planes. The anatomical landmarks were chosen from an average brain, spatially normalized to the Mon- treal Neurological Institute (MNI) space and the Talairach space. Major white matter path- ways were reconstructed with a deterministic tracking algorithm on a reference atlas and analyzed using the Brain-Grid system.ResultsIn all, 48 brain grid voxels (areas defined by 3 coordinates, axial (A), coronal (C), sagittal (S) and numbers from 1 to 4) were delineated in each MRI sequence and on the tractographic atlas. The number of grid voxels infiltrated was consistent, also in the MNI space. The sub- cortical insula/basal ganglia (A3-C2-S2) and the fronto-insular region (A3-C2-S1) were most frequently involved. The inferior fronto-occipital fasciculus, anterior thalamic radiation, unci- nate fasciculus, and external capsule were the most frequently associated pathways in both hemispheres.ConclusionsThe Brain-Grid based classification system provides an accurate observational tool in all patients with suspected gliomas, based on the comparison of grid voxels on a morphological MRI and segmented white matter atlas. Important biological information on tumor kinetics including extension, speed, and preferential direction of progression can be observed and even predicted with this system. This novel classification can easily be applied to both prospective and retrospective cohorts of patients and increase our comprehension of glioma behavior.
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| 7. |
- Latini, Francesco, et al.
(författare)
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Rapid and Accurate MRI Segmentation of Peritumoral Brain Edema in Meningiomas
- 2017
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Ingår i: Clinical neuroradiology. - : Springer Science and Business Media LLC. - 1869-1447 .- 1869-1439. ; 27:2, s. 145-152
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE:The extent of peritumoral brain edema (PTBE) in meningiomas commonly affects the clinical outcome. Despite its importance, edema volume is usually highly inaccurately approximated to a spheroid shape. We tested the accuracy and the reproducibility of semiautomatic lesion management software for the analysis of PTBE in a homogeneous case series of surgically confirmed intracranial meningiomas.METHODS:PTBE volume was calculated on magnetic resonance images in 50 patients with intracranial meningiomas using commercial lesion management software (Vue PACS Livewire, Carestream, Rochester, NY, USA). Inter and intraobserver agreement evaluation and a comparison between manual volume calculation, the semiautomatic software and spheroid approximation were performed in 22 randomly selected patients.RESULTS:The calculation of edema volume was possible in all cases irrespective of the extent of the signal changes. The median time for each calculation was 3 min. Interobserver and intraobserver agreement confirmed the reproducibility of the method. Comparison with standard (fully manual) calculation confirmed the accuracy of this software.CONCLUSIONS:Our study showed a high level of reproducibility of this semiautomatic computational method for peritumoral brain edema. It is rapid and easy to use after relatively short training and is suitable for implementation in clinical practice.
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| 8. |
- Latini, Francesco, 1982-, et al.
(författare)
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Rethinking the standard trans-cortical approaches in the light of superficial white matter anatomy
- 2015
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Ingår i: Neural Regeneration Research. - Meadows : Medknow. - 1673-5374 .- 1876-7958. ; 10:12, s. 1906-1909
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Forskningsöversikt (refereegranskat)abstract
- A better comprehension of the superficial white matter organization is important in order to minimize potential and avoidable damage to long or intermediate association fibre bundles during every step of a surgical approach. We recently proposed a technique for cadaver specimen preparation, which seems able to identify a more systematic organization of the superficial white matter terminations. Moreover, the use of the physiological intracranial vascular network for the fixation process allowed us to constantly show main vascular landmarks associated with white matter structures. Hence three examples of standard approaches to eloquent areas are herein reanalyzed starting from the first superficial layer. New insights into the possible surgical trajectories and subsequent quantitative damages of both vessels and white matter fibres can help readapt even the most standard and widely accepted approach trough the brain cortex. A more detailed study of these fine anatomical details may become in the near future a fundamental part of the neurosurgical training and the preoperative planning.
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| 9. |
- Ryttlefors, Mats, et al.
(författare)
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Intraoperative Intratumoral Embolization of a Complex Recurrent Hemangiopericytoma : Technical Report and Review of the Literature
- 2016
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Ingår i: Central European Neurosurgery. - : Georg Thieme Verlag KG. - 2193-6315 .- 2193-6323. ; 77:4, s. 361-366
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Forskningsöversikt (refereegranskat)abstract
- Objective Recurrent brain tumors represent a challenge for neurosurgeons because of the extensive blood loss and the time needed for surgical resection. Only a few hemostatic agents are useful to prevent the bleeding and thus facilitate the surgical resection. Fibrin sealant can be used to achieve sealing, tissue adherence, or hemostasis when other means of hemostasis are inadequate or inappropriate. We report the feasibility and positive effects of direct intratumoral injection of fibrin sealant during resection of a recurrent hemangiopericytoma. Material and Methods The intraoperative intratumoral injection of fibrin sealant changed the tumor properties of a recurrent hemangiopericytoma of the tentorium with infra- and supratentorial extension. From a loose friable briskly bleeding tumor, this complex lesion became a nonbleeding well-demarcated soft-firm tumor that could easily be dissected off the pial surface and totally resected without extensive bleeding. Results There are several benefits of intratumoral injection of fibrin sealant in hemangiopericytomas: (1) the extensive bleeding is diminished and blood loss minimized; (2) the restriction of the surgical view by the venous oozing is diminished, making the microsurgical dissection of the tumor capsule off the pial surface easier and safer; (3) the loose consistency of the tumor becomes firmer and facilitates the manipulation of the tumor and leads to a safer resection; and (4) a shorter operating time is needed. Conclusion The use of intratumoral fibrin glue injection is a safe and useful technique that could be used for hemostasis of highly vascularized tumors to facilitate a safer resection and to reduce blood loss.
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| 10. |
- Ryttlefors, Mats, et al.
(författare)
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Long-term evaluation of the effect of hypofractionated high-energy proton treatment of benign meningiomas by means of (11)C-L-methionine positron emission tomography
- 2016
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer Science and Business Media LLC. - 1619-7070 .- 1619-7089. ; 43:8, s. 1432-1443
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine if (11)C-L-methionine PET is a useful tool in the evaluation of the long-term effect of proton beam treatment in patients with meningioma remnant.METHODS: Included in the study were 19 patients (4 men, 15 women) with intracranial meningioma remnants who received hypofractionated high-energy proton beam treatment. Patients were examined with (11)C-L-methionine PET and MRI prior to treatment and after 6 months, and 1, 2, 3, 5, 7 and 10 years. Temporal changes in methionine uptake ratio, meningioma volume, meningioma regrowth and clinical symptoms throughout the follow-up period were evaluated.RESULTS: In 17 patients the tumour volume was unchanged throughout the follow-up. The methionine uptake ratio on PET decreased over the years in most patients. In two patients the tumour remnant showed progression on MRI. In these patients, prior to the volume increase on MRI, the methionine uptake ratio increased. One patient experienced transient clinical symptoms and showed radiological evidence of a radiation-induced reaction close to the irradiated field.CONCLUSION: Proton beam treatment is a safe and effective treatment for achieving long-term growth arrest in meningioma remnants. Follow-up with (11)C-L-methionine PET may be a valuable adjunct to, but not a replacement for, standard radiological follow-up.
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