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Seginer A, Schmidt R. Phase-based fast 3D high-resolution quantitative T 2 MRI in 7 T human brain imaging. Sci Rep 2022; 12:14088. [PMID: 35982143 PMCID: PMC9388657 DOI: 10.1038/s41598-022-17607-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 07/28/2022] [Indexed: 12/04/2022] Open
Abstract
Magnetic resonance imaging (MRI) is a powerful and versatile technique that offers a range of physiological, diagnostic, structural, and functional measurements. One of the most widely used basic contrasts in MRI diagnostics is transverse relaxation time (T2)-weighted imaging, but it provides only qualitative information. Realizing quantitative high-resolution T2 mapping is imperative for the development of personalized medicine, as it can enable the characterization of diseases progression. While ultra-high-field (≥ 7 T) MRI offers the means to gain new insights by increasing the spatial resolution, implementing fast quantitative T2 mapping cannot be achieved without overcoming the increased power deposition and radio frequency (RF) field inhomogeneity at ultra-high-fields. A recent study has demonstrated a new phase-based T2 mapping approach based on fast steady-state acquisitions. We extend this new approach to ultra-high field MRI, achieving quantitative high-resolution 3D T2 mapping at 7 T while addressing RF field inhomogeneity and utilizing low flip angle pulses; overcoming two main ultra-high field challenges. The method is based on controlling the coherent transverse magnetization in a steady-state gradient echo acquisition; achieved by utilizing low flip angles, a specific phase increment for the RF pulses, and short repetition times. This approach simultaneously extracts both T2 and RF field maps from the phase of the signal. Prior to in vivo experiments, the method was assessed using a 3D head-shaped phantom that was designed to model the RF field distribution in the brain. Our approach delivers fast 3D whole brain images with submillimeter resolution without requiring special hardware, such as multi-channel transmit coil, thus promoting high usability of the ultra-high field MRI in clinical practice.
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Affiliation(s)
| | - Rita Schmidt
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel. .,The Azrieli National Institute for Human Brain Imaging and Research, Weizmann Institute of Science, Rehovot, Israel.
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2
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Brun G, Testud B, Girard OM, Lehmann P, de Rochefort L, Besson P, Massire A, Ridley B, Girard N, Guye M, Ranjeva JP, Le Troter A. Automatic segmentation of Deep Grey Nuclei using a high-resolution 7T MRI Atlas - quantification of T1 values in healthy volunteers. Eur J Neurosci 2021; 55:438-460. [PMID: 34939245 DOI: 10.1111/ejn.15575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 11/30/2022]
Abstract
We present a new consensus atlas of deep grey nuclei obtained by shape-based averaging of manual segmentation of two experienced neuroradiologists and optimized from 7T MP2RAGE images acquired at (0.6mm)3 in 60 healthy subjects. A group-wise normalization method was used to build a high-contrast and high-resolution T1 -weighted brain template (0.5mm)3 using data from 30 out of the 60 controls. Delineation of 24 deep grey nuclei per hemisphere, including the claustrum and twelve thalamic nuclei, was then performed by two expert neuroradiologists and reviewed by a third neuroradiologist according to tissue contrast and external references based on the Morel atlas. Corresponding deep grey matter structures were also extracted from the Morel and CIT168 atlases. The data-derived, Morel and CIT168 atlases were all applied at the individual level using non-linear registration to fit the subject reference and to extract absolute mean quantitative T1 values derived from the 3D-MP2RAGE volumes, after correction for residual B1 + biases. Three metrics (The Dice and the volumetric similarity coefficients, and a novel Hausdorff distance) were used to estimate the inter-rater agreement of manual MRI segmentation and inter-atlas variability, and these metrics were measured to quantify biases due to image registration and their impact on the measurements of the quantitative T1 values was highlighted. This represents a fully-automated segmentation process permitting the extraction of unbiased normative T1 values in a population of young healthy controls as a reference for characterizing subtle structural alterations of deep grey nuclei relevant to a range of neurological diseases.
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Affiliation(s)
- Gilles Brun
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, Service de Neuroradiologie, Marseille, France
| | - Benoit Testud
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, Service de Neuroradiologie, Marseille, France
| | - Olivier M Girard
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
| | - Pierre Lehmann
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, Service de Neuroradiologie, Marseille, France
| | - Ludovic de Rochefort
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
| | - Pierre Besson
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
| | - Aurélien Massire
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
| | - Ben Ridley
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italia
| | - Nadine Girard
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, Service de Neuroradiologie, Marseille, France
| | - Maxime Guye
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
| | - Jean-Philippe Ranjeva
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
| | - Arnaud Le Troter
- Aix Marseille Univ, CNRS, CRMBM, Marseille, France.,AP-HM, CHU Timone, Pôle d'Imagerie Médicale, CEMEREM, Marseille, France
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3
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Yedavalli V, DiGiacomo P, Tong E, Zeineh M. High-resolution Structural Magnetic Resonance Imaging and Quantitative Susceptibility Mapping. Magn Reson Imaging Clin N Am 2021; 29:13-39. [PMID: 33237013 DOI: 10.1016/j.mric.2020.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
High-resolution 7-T imaging and quantitative susceptibility mapping produce greater anatomic detail compared with conventional strengths because of improvements in signal/noise ratio and contrast. The exquisite anatomic details of deep structures, including delineation of microscopic architecture using advanced techniques such as quantitative susceptibility mapping, allows improved detection of abnormal findings thought to be imperceptible on clinical strengths. This article reviews caveats and techniques for translating sequences commonly used on 1.5 or 3 T to high-resolution 7-T imaging. It discusses for several broad disease categories how high-resolution 7-T imaging can advance the understanding of various diseases, improve diagnosis, and guide management.
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Affiliation(s)
- Vivek Yedavalli
- Department of Radiology, Stanford University, 300 Pasteur Drive, Room S047, Stanford, CA 94305-5105, USA; Division of Neuroradiology, Johns Hopkins University, 600 N. Wolfe St. B-112 D, Baltimore, MD 21287, USA
| | - Phillip DiGiacomo
- Department of Bioengineering, Stanford University, Lucas Center for Imaging, Room P271, 1201 Welch Road, Stanford, CA 94305-5488, USA
| | - Elizabeth Tong
- Department of Radiology, 300 Pasteur Drive, Room S031, Stanford, CA 94305-5105, USA
| | - Michael Zeineh
- Department of Radiology, Stanford University, Lucas Center for Imaging, Room P271, 1201 Welch Road, Stanford, CA 94305-5488, USA.
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4
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Bıyık E, Keskin K, Uh Dar S, Koç A, Çukur T. Factorized sensitivity estimation for artifact suppression in phase-cycled bSSFP MRI. NMR IN BIOMEDICINE 2020; 33:e4228. [PMID: 31985879 DOI: 10.1002/nbm.4228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 10/08/2019] [Accepted: 10/25/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVE Balanced steady-state free precession (bSSFP) imaging suffers from banding artifacts in the presence of magnetic field inhomogeneity. The purpose of this study is to identify an efficient strategy to reconstruct banding-free bSSFP images from multi-coil multi-acquisition datasets. METHOD Previous techniques either assume that a naïve coil-combination is performed a priori resulting in suboptimal artifact suppression, or that artifact suppression is performed for each coil separately at the expense of significant computational burden. Here we propose a tailored method that factorizes the estimation of coil and bSSFP sensitivity profiles for improved accuracy and/or speed. RESULTS In vivo experiments show that the proposed method outperforms naïve coil-combination and coil-by-coil processing in terms of both reconstruction quality and time. CONCLUSION The proposed method enables computationally efficient artifact suppression for phase-cycled bSSFP imaging with modern coil arrays. Rapid imaging applications can efficiently benefit from the improved robustness of bSSFP imaging against field inhomogeneity.
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Affiliation(s)
- Erdem Bıyık
- Department of Electrical Engineering, Stanford University, CA, USA
- Intelligent Data Analytics Research Program Department, Aselsan Research Center, Ankara, Turkey
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
| | - Kübra Keskin
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Salman Uh Dar
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Aykut Koç
- Intelligent Data Analytics Research Program Department, Aselsan Research Center, Ankara, Turkey
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Tolga Çukur
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
- Neuroscience Program at Sabuncu Brain Research Center, Bilkent University, Ankara, Turkey
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5
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Shepherd TM, Hoch MJ, Bruno M, Faustin A, Papaioannou A, Jones SE, Devinsky O, Wisniewski T. Inner SPACE: 400-Micron Isotropic Resolution MRI of the Human Brain. Front Neuroanat 2020; 14:9. [PMID: 32265669 PMCID: PMC7103647 DOI: 10.3389/fnana.2020.00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 02/27/2020] [Indexed: 01/09/2023] Open
Abstract
Objectives Clinically relevant neuroanatomy is challenging to teach, learn and remember since many functionally important structures are visualized best using histology stains from serial 2D planar sections of the brain. In clinical patients, the locations of specific structures then must be inferred from spatial position and surface anatomy. A 3D MRI dataset of neuroanatomy has several advantages including simultaneous multi-planar visualization in the same brain, direct end-user manipulation of the data and image contrast identical to clinical MRI. We created 3D MRI datasets of the postmortem brain with high spatial and contrast resolution for simultaneous multi-planar visualization of complex neuroanatomy. Materials and Methods Whole human brains (N = 6) were immersion-fixed in 4% formaldehyde for 4 weeks, then washed continuously in water for 48 h. The brains were imaged on a clinical 3-T MRI scanner with a 64-channel head and neck coil using a 3D T2-weighted sequence with 400-micron isotropic resolution (voxel = 0.064 mm3; time = 7 h). Besides resolution, this sequence has multiple adjustments to improve contrast compared to a clinical protocol, including 93% reduced turbo factor and 77% reduced effective echo time. Results This MRI microscopy protocol provided excellent contrast resolution of small nuclei and internal myelinated pathways within the basal ganglia, thalamus, brainstem, and cerebellum. Contrast was sufficient to visualize the presence and variation of horizontal layers in the cerebral cortex. 3D isotropic resolution datasets facilitated simultaneous multi-planar visualization and efficient production of specific tailored oblique image orientations to improve understanding of complex neuroanatomy. Conclusion We created an unlabeled high-resolution digital 3D MRI dataset of neuroanatomy as an online resource for readers to download, manipulate, annotate and use for clinical practice, research, and teaching that is complementary to traditional histology-based atlases. Digital MRI contrast is quantifiable, reproducible across brains and could help validate novel MRI strategies for in vivo structure visualization.
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Affiliation(s)
- Timothy M Shepherd
- Department of Radiology, New York University, New York, NY, United States.,Center for Advanced Imaging Innovation and Research (CAI2R), New York, NY, United States
| | - Michael J Hoch
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Mary Bruno
- Department of Radiology, New York University, New York, NY, United States
| | - Arline Faustin
- Department of Pathology, New York University, New York, NY, United States
| | - Antonios Papaioannou
- Department of Radiology, New York University, New York, NY, United States.,Center for Advanced Imaging Innovation and Research (CAI2R), New York, NY, United States
| | - Stephen E Jones
- Department of Radiology, Cleveland Clinic, Cleveland, OH, United States
| | - Orrin Devinsky
- Department of Neurology, New York University, New York, NY, United States
| | - Thomas Wisniewski
- Department of Pathology, New York University, New York, NY, United States.,Department of Neurology, New York University, New York, NY, United States.,Department of Psychiatry, New York University, New York, NY, United States
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6
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DiGiacomo P, Maclaren J, Aksoy M, Tong E, Carlson M, Lanzman B, Hashmi S, Watkins R, Rosenberg J, Burns B, Skloss TW, Rettmann D, Rutt B, Bammer R, Zeineh M. A within-coil optical prospective motion-correction system for brain imaging at 7T. Magn Reson Med 2020; 84:1661-1671. [PMID: 32077521 DOI: 10.1002/mrm.28211] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 01/18/2020] [Accepted: 01/21/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE Motion artifact limits the clinical translation of high-field MR. We present an optical prospective motion correction system for 7 Tesla MRI using a custom-built, within-coil camera to track an optical marker mounted on a subject. METHODS The camera was constructed to fit between the transmit-receive coils with direct line of sight to a forehead-mounted marker, improving upon prior mouthpiece work at 7 Tesla MRI. We validated the system by acquiring a 3D-IR-FSPGR on a phantom with deliberate motion applied. The same 3D-IR-FSPGR and a 2D gradient echo were then acquired on 7 volunteers, with/without deliberate motion and with/without motion correction. Three neuroradiologists blindly assessed image quality. In 1 subject, an ultrahigh-resolution 2D gradient echo with 4 averages was acquired with motion correction. Four single-average acquisitions were then acquired serially, with the subject allowed to move between acquisitions. A fifth single-average 2D gradient echo was acquired following subject removal and reentry. RESULTS In both the phantom and human subjects, deliberate and involuntary motion were well corrected. Despite marked levels of motion, high-quality images were produced without spurious artifacts. The quantitative ratings confirmed significant improvements in image quality in the absence and presence of deliberate motion across both acquisitions (P < .001). The system enabled ultrahigh-resolution visualization of the hippocampus during a long scan and robust alignment of serially acquired scans with interspersed movement. CONCLUSION We demonstrate the use of a within-coil camera to perform optical prospective motion correction and ultrahigh-resolution imaging at 7 Tesla MRI. The setup does not require a mouthpiece, which could improve accessibility of motion correction during 7 Tesla MRI exams.
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Affiliation(s)
- Phillip DiGiacomo
- Department of Bioengineering, Stanford University, Stanford, California
| | - Julian Maclaren
- Department of Radiology, Stanford University, Stanford, California
| | - Murat Aksoy
- Department of Radiology, Stanford University, Stanford, California
| | - Elizabeth Tong
- Department of Radiology, Stanford University, Stanford, California
| | - Mackenzie Carlson
- Department of Bioengineering, Stanford University, Stanford, California
| | - Bryan Lanzman
- Department of Radiology, Stanford University, Stanford, California
| | - Syed Hashmi
- Department of Radiology, Stanford University, Stanford, California
| | - Ronald Watkins
- Department of Radiology, Stanford University, Stanford, California
| | | | - Brian Burns
- Applied Sciences Lab West, GE Healthcare, Menlo Park, California
| | | | - Dan Rettmann
- MR Applications and Workflow, GE Healthcare, Rochester, Minnesota
| | - Brian Rutt
- Department of Bioengineering, Stanford University, Stanford, California.,Department of Radiology, Stanford University, Stanford, California
| | - Roland Bammer
- Department of Radiology, University of Melbourne, Melbourne, Australia
| | - Michael Zeineh
- Department of Radiology, Stanford University, Stanford, California
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7
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Maruyama S, Fukunaga M, Fautz HP, Heidemann R, Sadato N. Comparison of 3T and 7T MRI for the visualization of globus pallidus sub-segments. Sci Rep 2019; 9:18357. [PMID: 31797993 PMCID: PMC6892946 DOI: 10.1038/s41598-019-54880-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/20/2019] [Indexed: 12/17/2022] Open
Abstract
The success of deep brain stimulation (DBS) targeting the internal globus pallidus (GPi) depends on the accuracy of electrode localization inside the GPi. In this study, we sought to compare visualization of the medial medullary lamina (MML) and accessory medullary lamina (AML) between proton density-weighted (PDW) and T2-weighted (T2W) sequences on 3T and 7T MRI scanners. Eleven healthy participants (five men and six women; age, 19–28 years; mean, 21.5) and one 61-year-old man were scanned using two-dimensional turbo spin-echo PDW and T2W sequences on 3T and 7T MRI scanners with a 32-channel receiver head coil and a single-channel transmission coil. Profiles of signal intensity were obtained from the pixel values of straight lines over the GP regions crossing the MML and AML. Contrast ratios (CRs) for GPe/MML, GPie/MML, GPie/AML, and GPii/AML were calculated. Qualitatively, 7T visualized both the MML and AML, whereas 3T visualized the MML less clearly and hardly depicted the AML. The T2W sequence at 7T yielded significantly higher CRs for GPie/MML, GPie/AML, and GPii/AML than the PDW sequence at 7T or 3T. The T2W sequence at 7T allows visualization of the internal structures of GPi segments with high signal intensity and contrast.
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Affiliation(s)
- Shuki Maruyama
- Department of System Neuroscience, Division of Cerebral Integration, National Institute for Physiological Sciences (NIPS), 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa, 240-0193, Japan
| | - Masaki Fukunaga
- Department of System Neuroscience, Division of Cerebral Integration, National Institute for Physiological Sciences (NIPS), 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa, 240-0193, Japan
| | - Hans-Peter Fautz
- Siemens Healthineers, Allee am Roethelheimpark 2, 91052, Erlangen, Germany
| | - Robin Heidemann
- Siemens Healthineers, Allee am Roethelheimpark 2, 91052, Erlangen, Germany
| | - Norihiro Sadato
- Department of System Neuroscience, Division of Cerebral Integration, National Institute for Physiological Sciences (NIPS), 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan. .,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa, 240-0193, Japan.
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8
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François Q, André A, Duplat B, Haliyo S, Régnier S. Tracking systems for intracranial medical devices: A review. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/mds3.10033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Quentin François
- Institute of Intelligent and Robotic Systems (ISIR) Sorbonne University Paris France
- Robeauté Paris France
| | - Arthur André
- Department of Neurosurgery La Pitié‐Salpêtrière Hospital Paris France
| | | | - Sinan Haliyo
- Institute of Intelligent and Robotic Systems (ISIR) Sorbonne University Paris France
| | - Stéphane Régnier
- Institute of Intelligent and Robotic Systems (ISIR) Sorbonne University Paris France
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9
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Keuken MC, Isaacs BR, Trampel R, van der Zwaag W, Forstmann BU. Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging. Brain Topogr 2018; 31:513-545. [PMID: 29497874 PMCID: PMC5999196 DOI: 10.1007/s10548-018-0638-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 01/28/2018] [Indexed: 12/15/2022]
Abstract
With the recent increased availability of ultra-high field (UHF) magnetic resonance imaging (MRI), substantial progress has been made in visualizing the human brain, which can now be done in extraordinary detail. This review provides an extensive overview of the use of UHF MRI in visualizing the human subcortex for both healthy and patient populations. The high inter-subject variability in size and location of subcortical structures limits the usability of atlases in the midbrain. Fortunately, the combined results of this review indicate that a large number of subcortical areas can be visualized in individual space using UHF MRI. Current limitations and potential solutions of UHF MRI for visualizing the subcortex are also discussed.
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Affiliation(s)
- M C Keuken
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, Postbus 15926, 1001NK, Amsterdam, The Netherlands.
- Cognitive Psychology Unit, Institute of Psychology and Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands.
| | - B R Isaacs
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, Postbus 15926, 1001NK, Amsterdam, The Netherlands
- Maastricht University Medical Center, Maastricht, The Netherlands
| | - R Trampel
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | | | - B U Forstmann
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, Postbus 15926, 1001NK, Amsterdam, The Netherlands
- Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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10
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How to choose the right MR sequence for your research question at 7 T and above? Neuroimage 2018; 168:119-140. [DOI: 10.1016/j.neuroimage.2017.04.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 12/29/2022] Open
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11
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Zeineh MM, Palomero-Gallagher N, Axer M, Gräßel D, Goubran M, Wree A, Woods R, Amunts K, Zilles K. Direct Visualization and Mapping of the Spatial Course of Fiber Tracts at Microscopic Resolution in the Human Hippocampus. Cereb Cortex 2017; 27:1779-1794. [PMID: 26874183 DOI: 10.1093/cercor/bhw010] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
While hippocampal connectivity is essential to normal memory function, our knowledge of human hippocampal circuitry is largely inferred from animal studies. Using polarized light microscopy at 1.3 µm resolution, we have directly visualized the 3D course of key medial temporal pathways in 3 ex vivo human hemispheres and 2 ex vivo vervet monkey hemispheres. The multiple components of the perforant path system were clearly identified: Superficial sheets of fibers emanating from the entorhinal cortex project to the presubiculum and parasubiculum, intermixed transverse and longitudinal angular bundle fibers perforate the subiculum and then project to the cornu ammonis (CA) fields and dentate molecular layer, and a significant alvear component runs from the angular bundle to the CA fields. From the hilus, mossy fibers localize to regions of high kainate receptor density, and the endfolial pathway, mostly investigated in humans, merges with the Schaffer collaterals. This work defines human hippocampal pathways underlying mnemonic function at an unprecedented resolution.
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Affiliation(s)
- Michael M Zeineh
- Department of Radiology, Stanford University, Lucas Center for Imaging, Stanford, CA 94305, USA
| | | | - Markus Axer
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - David Gräßel
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Maged Goubran
- Department of Radiology, Stanford University, Lucas Center for Imaging, Stanford, CA 94305, USA
| | - Andreas Wree
- Institute of Anatomy, University of Rostock, Rostock, Germany
| | - Roger Woods
- Ahmanson-Lovelace Brain Mapping Center, David Geffen School of Medicine UCLA, Los Angeles, USA
| | - Katrin Amunts
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany.,C. and O. Vogt Institute for Brain Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Karl Zilles
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany.,Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany.,JARA Jülich-Aachen Research Alliance, Translational Brain Medicine, Jülich, Germany
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12
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Barrett TF, Dyvorne HA, Padormo F, Pawha PS, Delman BN, Shrivastava RK, Balchandani P. First Application of 7-T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors. World Neurosurg 2017; 103:600-610. [PMID: 28359922 DOI: 10.1016/j.wneu.2017.03.088] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 03/18/2017] [Accepted: 03/20/2017] [Indexed: 01/16/2023]
Abstract
BACKGROUND Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7-T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of the skull base. In this study, we apply a 7-T imaging protocol to patients with skull base tumors and compare the images with clinical standard of care. METHODS Images were acquired at 7 T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5-, 3-, and 7-T scans for detection of intracavernous cranial nerves and internal carotid artery (ICA) branches. Detection rates were compared. Images were used for surgical planning and uploaded to a neuronavigation platform and used to guide surgery. RESULTS Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7 T. The 7-T images were successfully incorporated into preoperative planning and intraoperative neuronavigation. CONCLUSIONS Our study represents the first application of 7-T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7-T MRI compared with 3- and 1.5-T MRI, and found that integration of 7 T into surgical planning and guidance was feasible. These results suggest a potential for 7-T MRI to reduce surgical complications. Future studies comparing standardized 7-, 3-, and 1.5-T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7-T MRI for endonasal endoscopic surgical efficacy.
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Affiliation(s)
- Thomas F Barrett
- Department of Neurosurgery, Mount Sinai Medical Center, New York, NY, USA.
| | - Hadrien A Dyvorne
- The Translational and Molecular Imaging Institute, Mount Sinai Medical Center, New York, NY, USA
| | - Francesco Padormo
- The Translational and Molecular Imaging Institute, Mount Sinai Medical Center, New York, NY, USA
| | - Puneet S Pawha
- Department of Radiology, Mount Sinai Medical Center, New York, NY, USA
| | - Bradley N Delman
- Department of Radiology, Mount Sinai Medical Center, New York, NY, USA
| | - Raj K Shrivastava
- Department of Neurosurgery, Mount Sinai Medical Center, New York, NY, USA
| | - Priti Balchandani
- The Translational and Molecular Imaging Institute, Mount Sinai Medical Center, New York, NY, USA
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High-Resolution Axonal Bundle (Fascicle) Assessment and Triple-Echo Steady-State T2 Mapping of the Median Nerve at 7 T. Invest Radiol 2016; 51:529-35. [DOI: 10.1097/rli.0000000000000265] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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14
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Federau C, Gallichan D. Motion-Correction Enabled Ultra-High Resolution In-Vivo 7T-MRI of the Brain. PLoS One 2016; 11:e0154974. [PMID: 27159492 PMCID: PMC4861298 DOI: 10.1371/journal.pone.0154974] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/21/2016] [Indexed: 11/19/2022] Open
Abstract
Objectives To demonstrate the image quality that can be obtained for multiple contrasts using ultra-high resolution MRI (highest nominal resolution: 350 μm isotropic) at 7T using appropriate motion-correction. Materials and Methods An MRI-based fat-excitation motion navigator (which requires no additional hardware) was incorporated into T1-weighted (MP2RAGE, 350 μm nominal isotropic resolution, total scan time 124 mins over 2 sessions. The MP2RAGE also provides quantitative T1-maps), 3D-TSE (380 μm nominal isotropic resolution, total scan time 58 mins) and T2*-weighted protocols (3D-GRE, 380 μm nominal isotropic resolution, total scan time 42 mins) on a 7T MR system. Images from each contrast are presented from a single healthy adult male volunteer (34 years) for direct comparison. The subject provided written consent in accordance with the local review board. Results Images of various brain structures are revealed at unprecedented quality for in-vivo MRI. The presented images permit, for example, to delimit the internal structure of the basal ganglia and thalamus. The single digitationes of the hippocampus are visible, and the gyrus dentatus can be visualized. Intracortical contrast was also observed in the neocortex, including the stria of Gennari of the primary visual cortex. Conclusions Appropriate motion-correction allows MRI scans to be performed with extended scan times enabling exceptionally high resolution scans with high image quality, with the use of a 7T scanner allowing large brain coverage for 350–380 μm isotropic voxels with total scan times for each contrast ranging from 42 to 124 minutes.
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Affiliation(s)
- Christian Federau
- Dept of Radiology, Section of Neuroradiology, Stanford University, Stanford, California, United States of America
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15
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Magnetic Resonance Imaging and Computed Tomography of the Brain—50 Years of Innovation, With a Focus on the Future. Invest Radiol 2015; 50:551-6. [DOI: 10.1097/rli.0000000000000170] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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16
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Yamada I, Miyasaka N, Hikishima K, Tokairin Y, Kawano T, Ito E, Kobayashi D, Eishi Y, Okano H. Ultra-high-resolution MR imaging of esophageal carcinoma at ultra-high field strength (7.0T) ex vivo: correlation with histopathologic findings. Magn Reson Imaging 2015; 33:413-9. [DOI: 10.1016/j.mri.2014.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 10/16/2014] [Accepted: 11/24/2014] [Indexed: 01/21/2023]
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17
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Diffusion-Sensitized Ophthalmic Magnetic Resonance Imaging Free of Geometric Distortion at 3.0 and 7.0 T. Invest Radiol 2015; 50:309-21. [DOI: 10.1097/rli.0000000000000129] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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18
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Ultra-high resolution in-vivo 7.0T structural imaging of the human hippocampus reveals the endfolial pathway. Neuroimage 2015; 112:1-6. [PMID: 25701699 DOI: 10.1016/j.neuroimage.2015.02.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 11/20/2022] Open
Abstract
The hippocampus is a very important structure in memory formation and retrieval, as well as in various neurological disorders such as Alzheimer's disease, epilepsy and depression. It is composed of many intricate subregions making it difficult to study the anatomical changes that take place during disease. The hippocampal hilus may have a unique neuroanatomy in humans compared to that in monkeys and rodents, with field CA3h greatly enlarged in humans compared to that in rodents, and a white-matter pathway, called the endfolial pathway, possibly only present in humans. In this study we have used newly developed 7.0T whole brain imaging sequence, balanced steady-state free precession (bSSFP) that can achieve 0.4mm isotropic images to study, in vivo, the anatomy of the hippocampal hilus. A detailed hippocampal subregional segmentation was performed according to anatomic atlases segmenting the following regions: CA4, CA3, CA2, CA1, SRLM (stratum radiatum lacunosum moleculare), alveus, fornix, and subiculum along with its molecular layer. We also segmented a hypointense structure centrally within the hilus that resembled the endfolial pathway. To validate that this hypointense signal represented the endfolial pathway, we acquired 0.1mm isotropic 8-phase cycle bSSFP on an excised specimen, and then sectioned and stained the specimen for myelin using an anti-myelin basic protein antibody (SMI 94). A structure tensor analysis was calculated on the myelin-stained section to show directionality of the underlying fibers. The endfolial pathway was consistently visualized within the hippocampal body in vivo in all subjects. It is a central pathway in the hippocampus, with unknown relevance in neurodegenerative disorders, but now that it can be visualized noninvasively, we can study its function and alterations in neurodegeneration.
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Yamada I, Miyasaka N, Hikishima K, Kato K, Kojima K, Kawano T, Ito E, Kobayashi D, Eishi Y, Okano H. Gastric Carcinoma: Ex Vivo MR Imaging at 7.0 T-Correlation with Histopathologic Findings. Radiology 2015; 275:841-8. [PMID: 25584712 DOI: 10.1148/radiol.14141878] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
PURPOSE To determine the imaging detail and diagnostic information that can be obtained at 7.0-T magnetic resonance (MR) imaging with a voxel volume of 9.5-14.0 nL as a means of evaluating the depth of mural invasion by gastric carcinomas ex vivo. MATERIALS AND METHODS This study was approved by the institutional review board, and written informed consent was obtained from each patient. Twenty gastric specimens containing 20 carcinomas were studied with a 7.0-T MR imaging system equipped with a four-channel surface coil. MR images were obtained with a 50-60 × 25-30 mm field of view, a 512 × 256 matrix, and a 1.0-mm section thickness, resulting in a voxel volume of 0.0095-0.0140 mm(3) (9.5-14.0 nL). The signal intensity of the gastric wall layers, tumor tissue, and fibrosis was described as low, intermediate, or high by comparing it with the signal intensity of the muscularis propria. Depth of invasion initially was assessed by two reviewers independently and then by the two reviewers in consensus. MR images were compared with histopathologic findings. RESULTS The 7.0-T T2-weighted MR images clearly depicted the normal gastric wall in all 20 specimens (100%) as consisting of seven layers, which clearly corresponded to the tissue layers of the gastric wall. These MR images enabled clear differentiation between tumor tissue and fibrosis. Reviewers disagreed on the depth of invasion at the initial reading in three (15%) of 20 specimens (between mucosa and submucosa in two specimens and between muscularis propria and subserosa and serosa in one specimen); however, in all 20 gastric carcinomas, the depth of invasion could be accurately determined on T2-weighted images after consensus interpretation. CONCLUSION Ex vivo 7.0-T MR imaging enables clear delineation of the gastric wall layers and clear differentiation of tumor tissue from fibrosis and allows one to assess the depth of mural invasion by gastric carcinomas.
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Affiliation(s)
- Ichiro Yamada
- From the Departments of Diagnostic Radiology and Oncology (I.Y.), Pediatrics, Perinatal and Maternal Medicine (N.M.), Gastric Surgery (K. Kato, K. Kojima), Esophageal Surgery (T.K.), and Pathology (E.I., D.K., Y.E.), Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan; Department of Physiology, Keio University School of Medicine, Tokyo, Japan (K.H., H.O.); and Central Institute for Experimental Animals, Kawasaki, Japan (K.H.)
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Suthana NA, Donix M, Wozny DR, Bazih A, Jones M, Heidemann RM, Trampel R, Ekstrom AD, Scharf M, Knowlton B, Turner R, Bookheimer SY. High-resolution 7T fMRI of Human Hippocampal Subfields during Associative Learning. J Cogn Neurosci 2014; 27:1194-206. [PMID: 25514656 DOI: 10.1162/jocn_a_00772] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Examining the function of individual human hippocampal subfields remains challenging because of their small sizes and convoluted structures. Previous human fMRI studies at 3 T have successfully detected differences in activation between hippocampal cornu ammonis (CA) field CA1, combined CA2, CA3, and dentate gyrus (DG) region (CA23DG), and the subiculum during associative memory tasks. In this study, we investigated hippocampal subfield activity in healthy participants using an associative memory paradigm during high-resolution fMRI scanning at 7 T. We were able to localize fMRI activity to anterior CA2 and CA3 during learning and to the posterior CA2 field, the CA1, and the posterior subiculum during retrieval of novel associations. These results provide insight into more specific human hippocampal subfield functions underlying learning and memory and a unique opportunity for future investigations of hippocampal subfield function in healthy individuals as well as those suffering from neurodegenerative diseases.
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