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Xu G, Zhao Z, Zhu Q, Zhu K, Zhang J, Wu D. Myelin water imaging of in vivo and ex vivo human brains using multi-echo gradient echo at 3 T and 7 T. Magn Reson Med 2024. [PMID: 39370873 DOI: 10.1002/mrm.30310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2024] [Revised: 08/08/2024] [Accepted: 09/03/2024] [Indexed: 10/08/2024]
Abstract
PURPOSE To compare the myelin water fraction (MWF) measurements between 3 T and 7 T and between in vivo and ex vivo human brains, and to investigate the relationship between multi-echo gradient-echo (mGRE)-based 3D MWF and myelin content using histological staining, which has not been validated in the human brain. METHODS In this study, we performed 3D mGRE-based MWF measurements on five ex vivo human brain hemispheres and five healthy volunteers at 3 T and 7 T with 1 mm isotropic resolution. The data were fitted with theT 2 * $$ {\mathrm{T}}_2^{\ast } $$ based on a three compartment complex-valued model to estimate MWF. We obtained myelin basic protein (MBP) staining from two tissue blocks and co-registered the MWF map and histology image for voxel-wise correlation between the two. RESULTS The MWF values measured from 7 T were overall higher than 7 T, but data between the two field strength demonstrated high correlations both in vivo (r = 0.88) and ex vivo (r = 0.83) across 19 white matter regions. Moreover, the MWF measurements showed a good agreement between in vivo and ex vivo assessments at 3 T (r = 0.61) and 7 T (r = 0.54). Based on MBP staining, the MWF values exhibited strong positive correlations with myelin content on both 3 T (r = 0.68 and r = 0.78 for the two tissue blocks) and 7 T (r = 0.64 and r = 0.82 for the two tissue blocks). CONCLUSION The findings demonstrated that the mGRE-based MWF mapping can be used to quantify myelin content in the human brain, despite the field-strength dependency of the measurements.
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Affiliation(s)
- Guojun Xu
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
| | - Zhiyong Zhao
- Children's Hospital, National Clinical Research Center for Child Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Qinfeng Zhu
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
| | - Keqing Zhu
- China Brain Bank and Department of Neurology in Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of Zhejiang Province, and Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
- Department of Pathology, The First Affiliated Hospital and School of Medicine, Zhejiang University, Hangzhou, China
| | - Jing Zhang
- China Brain Bank and Department of Neurology in Second Affiliated Hospital, Key Laboratory of Medical Neurobiology of Zhejiang Province, and Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
- Department of Pathology, The First Affiliated Hospital and School of Medicine, Zhejiang University, Hangzhou, China
| | - Dan Wu
- Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
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Neuhaus D, Rost T, Haas T, Wendebourg MJ, Schulze K, Schlaeger R, Scheurer E, Lenz C. Comparative analysis of in situ and ex situ postmortem brain MRI: Evaluating volumetry, DTI, and relaxometry. Magn Reson Med 2024. [PMID: 39250425 DOI: 10.1002/mrm.30264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 08/05/2024] [Accepted: 08/06/2024] [Indexed: 09/11/2024]
Abstract
PURPOSE To compare postmortem in situ with ex situ MRI parameters, including volumetry, diffusion tensor imaging (DTI), and relaxometry for assessing methodology-induced alterations, which is a crucial prerequisite when performing MRI biomarker validation. METHODS MRI whole-brain scans of five deceased patients with amyotrophic lateral sclerosis were performed at 3 T. In situ scans were conducted within 32 h after death (SD 18 h), and ex situ scans after brain extraction and 3 months of formalin fixation. The imaging protocol included MP2RAGE, DTI, and multi-contrast spin-echo and multi-echo gradient-echo sequences. Volumetry, fractional anisotropy, mean diffusivity, T1, T2, andT 2 * $$ {T}_2^{\ast } $$ have been assessed for specific brain regions. RESULTS When comparing ex situ to in situ values, the following results were obtained. Deep gray matter as well as the thalamus and the hippocampus showed a reduced volume. Fractional anisotropy was reduced in the cortex and the whole brain. Mean diffusivity was decreased in white matter and deep gray matter. T1 and T2 were reduced in all investigated structures, whereasT 2 * $$ {T}_2^{\ast } $$ was increased in the cortex. CONCLUSION The results of this study show that the volumes and MRI parameters of several brain regions are potentially affected by tissue extraction and subsequent formalin fixation, suggesting that methodological alterations are present in ex situ MRI. To avoid overlap of indistinguishable methodological and disease-related changes, we recommend performing in situ postmortem MRI as an additional intermediate step for in vivo MRI biomarker validation.
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Affiliation(s)
- Dominique Neuhaus
- Institute of Forensic Medicine, Department of Biomedical Engineering, University of Basel, Basel, Switzerland
- Institute of Forensic Medicine, Health Department Basel-Stadt, Basel, Switzerland
| | - Thomas Rost
- Institute of Forensic Medicine, Health Department Basel-Stadt, Basel, Switzerland
| | - Tanja Haas
- Division of Radiological Physics, Department of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Switzerland
| | - Maria Janina Wendebourg
- Neurology Clinic and Policlinic, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
- Translational Imaging in Neurology (ThINk), Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Katja Schulze
- Institute of Forensic Medicine, Health Department Basel-Stadt, Basel, Switzerland
| | - Regina Schlaeger
- Neurology Clinic and Policlinic, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
- Translational Imaging in Neurology (ThINk), Department of Biomedical Engineering, University of Basel, Basel, Switzerland
| | - Eva Scheurer
- Institute of Forensic Medicine, Department of Biomedical Engineering, University of Basel, Basel, Switzerland
- Institute of Forensic Medicine, Health Department Basel-Stadt, Basel, Switzerland
| | - Claudia Lenz
- Institute of Forensic Medicine, Department of Biomedical Engineering, University of Basel, Basel, Switzerland
- Institute of Forensic Medicine, Health Department Basel-Stadt, Basel, Switzerland
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McKenzie AT, Zeleznikow-Johnston A, Sparks JS, Nnadi O, Smart J, Wiley K, Cerullo MA, de Wolf A, Minerva F, Risco R, Church GM, de Magalhães JP, Kendziorra EF. Structural brain preservation: a potential bridge to future medical technologies. FRONTIERS IN MEDICAL TECHNOLOGY 2024; 6:1400615. [PMID: 39315362 PMCID: PMC11416988 DOI: 10.3389/fmedt.2024.1400615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 08/21/2024] [Indexed: 09/25/2024] Open
Abstract
When faced with the prospect of death, some people would prefer a form of long-term preservation that may allow them to be restored to healthy life in the future, if technology ever develops to the point that this is feasible and humane. Some believe that we may have the capacity to perform this type of experimental preservation today-although it has never been proven-using contemporary methods to preserve the structure of the brain. The idea is that the morphomolecular organization of the brain encodes the information required for psychological properties such as personality and long-term memories. If these structures in the brain can be maintained intact over time, this could theoretically provide a bridge to access restorative technologies in the future. To consider this hypothesis, we first describe possible metrics that can be used to assess structural brain preservation quality. We next explore several possible methods to preserve structural information in the brain, including the traditional cryonics method of cryopreservation, as well as aldehyde-stabilized cryopreservation and fluid preservation. We focus in-depth on fluid preservation, which relies on aldehyde fixation to induce chemical gel formation in a wide set of biomolecules and appears to be a cost-effective method. We describe two theoretical recovery technologies, alongside several of the ethical and legal complexities of brain preservation, all of which will require a prudent approach. We believe contemporary structural brain preservation methods have a non-negligible chance of allowing successful restoration in the future and that this deserves serious research efforts by the scientific community.
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Affiliation(s)
| | - Ariel Zeleznikow-Johnston
- School of Psychological Sciences, Monash University, Melbourne, VIC, Australia
- Turner Institute for Brain and Mental Health, Monash University, Melbourne, VIC, Australia
| | | | - Oge Nnadi
- Brain Preservation Foundation, Ashburn, VA, United States
| | - John Smart
- Brain Preservation Foundation, Ashburn, VA, United States
| | - Keith Wiley
- Brain Preservation Foundation, Ashburn, VA, United States
| | | | | | | | - Ramón Risco
- Escuela Superior de Ingeniería, Universidad de Sevilla & National Accelerators Center, CNA-CSIC, Seville, Spain
| | - George M. Church
- Department of Genetics, Harvard Medical School, Boston, MA, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, United States
| | - João Pedro de Magalhães
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
- Oxford Uehiro Centre for Practical Ethics, University of Oxford, Oxford, United Kingdom
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Behroozi M, Graïc JM, Gerussi T. Beyond the surface: how ex-vivo diffusion-weighted imaging reveals large animal brain microstructure and connectivity. Front Neurosci 2024; 18:1411982. [PMID: 38988768 PMCID: PMC11233460 DOI: 10.3389/fnins.2024.1411982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/12/2024] [Indexed: 07/12/2024] Open
Abstract
Diffusion-weighted Imaging (DWI) is an effective and state-of-the-art neuroimaging method that non-invasively reveals the microstructure and connectivity of tissues. Recently, novel applications of the DWI technique in studying large brains through ex-vivo imaging enabled researchers to gain insights into the complex neural architecture in different species such as those of Perissodactyla (e.g., horses and rhinos), Artiodactyla (e.g., bovids, swines, and cetaceans), and Carnivora (e.g., felids, canids, and pinnipeds). Classical in-vivo tract-tracing methods are usually considered unsuitable for ethical and practical reasons, in large animals or protected species. Ex-vivo DWI-based tractography offers the chance to examine the microstructure and connectivity of formalin-fixed tissues with scan times and precision that is not feasible in-vivo. This paper explores DWI's application to ex-vivo brains of large animals, highlighting the unique insights it offers into the structure of sometimes phylogenetically different neural networks, the connectivity of white matter tracts, and comparative evolutionary adaptations. Here, we also summarize the challenges, concerns, and perspectives of ex-vivo DWI that will shape the future of the field in large brains.
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Affiliation(s)
- Mehdi Behroozi
- Department of Biopsychology, Faculty of Psychology, Institute of Cognitive Neuroscience, Ruhr-University Bochum, Bochum, Germany
| | - Jean-Marie Graïc
- Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Italy
| | - Tommaso Gerussi
- Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Italy
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
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5
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Khandelwal P, Duong MT, Sadaghiani S, Lim S, Denning AE, Chung E, Ravikumar S, Arezoumandan S, Peterson C, Bedard M, Capp N, Ittyerah R, Migdal E, Choi G, Kopp E, Loja B, Hasan E, Li J, Bahena A, Prabhakaran K, Mizsei G, Gabrielyan M, Schuck T, Trotman W, Robinson J, Ohm DT, Lee EB, Trojanowski JQ, McMillan C, Grossman M, Irwin DJ, Detre JA, Tisdall MD, Das SR, Wisse LEM, Wolk DA, Yushkevich PA. Automated deep learning segmentation of high-resolution 7 Tesla postmortem MRI for quantitative analysis of structure-pathology correlations in neurodegenerative diseases. IMAGING NEUROSCIENCE (CAMBRIDGE, MASS.) 2024; 2:1-30. [PMID: 39301426 PMCID: PMC11409836 DOI: 10.1162/imag_a_00171] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/01/2024] [Accepted: 04/15/2024] [Indexed: 09/22/2024]
Abstract
Postmortem MRI allows brain anatomy to be examined at high resolution and to link pathology measures with morphometric measurements. However, automated segmentation methods for brain mapping in postmortem MRI are not well developed, primarily due to limited availability of labeled datasets, and heterogeneity in scanner hardware and acquisition protocols. In this work, we present a high-resolution dataset of 135 postmortem human brain tissue specimens imaged at 0.3 mm3 isotropic using a T2w sequence on a 7T whole-body MRI scanner. We developed a deep learning pipeline to segment the cortical mantle by benchmarking the performance of nine deep neural architectures, followed by post-hoc topological correction. We evaluate the reliability of this pipeline via overlap metrics with manual segmentation in 6 specimens, and intra-class correlation between cortical thickness measures extracted from the automatic segmentation and expert-generated reference measures in 36 specimens. We also segment four subcortical structures (caudate, putamen, globus pallidus, and thalamus), white matter hyperintensities, and the normal appearing white matter, providing a limited evaluation of accuracy. We show generalizing capabilities across whole-brain hemispheres in different specimens, and also on unseen images acquired at 0.28 mm3 and 0.16 mm3 isotropic T2*w fast low angle shot (FLASH) sequence at 7T. We report associations between localized cortical thickness and volumetric measurements across key regions, and semi-quantitative neuropathological ratings in a subset of 82 individuals with Alzheimer's disease (AD) continuum diagnoses. Our code, Jupyter notebooks, and the containerized executables are publicly available at the project webpage (https://pulkit-khandelwal.github.io/exvivo-brain-upenn/).
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Affiliation(s)
- Pulkit Khandelwal
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael Tran Duong
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Shokufeh Sadaghiani
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Sydney Lim
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Amanda E. Denning
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Eunice Chung
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Sadhana Ravikumar
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Sanaz Arezoumandan
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Claire Peterson
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Madigan Bedard
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Noah Capp
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Ranjit Ittyerah
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Elyse Migdal
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Grace Choi
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Emily Kopp
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Bridget Loja
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Eusha Hasan
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Jiacheng Li
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Alejandra Bahena
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Karthik Prabhakaran
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Gabor Mizsei
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Marianna Gabrielyan
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Theresa Schuck
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Winifred Trotman
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - John Robinson
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Daniel T. Ohm
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Edward B. Lee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - John Q. Trojanowski
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Corey McMillan
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Murray Grossman
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - David J. Irwin
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - John A. Detre
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - M. Dylan Tisdall
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Sandhitsu R. Das
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | | | - David A. Wolk
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Paul A. Yushkevich
- Penn Image Computing and Science Laboratory, University of Pennsylvania, Philadelphia, PA, United States
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States
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Mignucci-Jiménez G, Xu Y, On TJ, Abramov I, Houlihan LM, Rahmani R, Koskay G, Hanalioglu S, Meybodi AT, Lawton MT, Preul MC. Toward an optimal cadaveric brain model for neurosurgical education: assessment of preservation, parenchyma, vascular injection, and imaging. Neurosurg Rev 2024; 47:190. [PMID: 38658446 DOI: 10.1007/s10143-024-02363-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/13/2024] [Accepted: 03/16/2024] [Indexed: 04/26/2024]
Abstract
OBJECTIVE We assessed types of cadaveric head and brain tissue specimen preparations that are used in a high throughput neurosurgical research laboratory to determine optimal preparation methods for neurosurgical anatomical research, education, and training. METHODS Cadaveric specimens (N = 112) prepared using different preservation and vascular injection methods were imaged, dissected, and graded by 11 neurosurgeons using a 21-point scale. We assessed the quality of tissue and preservation in both the anterior and posterior circulations. Tissue quality was evaluated using a 9-point magnetic resonance imaging (MRI) scale. RESULTS Formalin-fixed specimens yielded the highest scores for assessment (mean ± SD [17.0 ± 2.8]) vs. formalin-flushed (17.0 ± 3.6) and MRI (6.9 ± 2.0). Cadaver assessment and MRI scores were positively correlated (P < 0.001, R2 0.60). Analysis showed significant associations between cadaver assessment scores and specific variables: nonformalin fixation (β = -3.3), preservation within ≤72 h of death (β = 1.8), and MRI quality score (β = 0.7). Formalin-fixed specimens exhibited greater hardness than formalin-flushed and nonformalin-fixed specimens (P ≤ 0.006). Neurosurgeons preferred formalin-flushed specimens injected with colored latex. CONCLUSION For better-quality specimens for neurosurgical education and training, formalin preservation within ≤72 h of death was preferable, as was injection with colored latex. Formalin-flushed specimens more closely resembled live brain parenchyma. Assessment scores were lower for preparation techniques performed > 72 h postmortem and for nonformalin preservation solutions. The positive correlation between cadaver assessment scores and our novel MRI score indicates that donation organizations and institutional buyers should incorporate MRI as a screening tool for the selection of high-quality specimens.
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Affiliation(s)
- Giancarlo Mignucci-Jiménez
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Yuan Xu
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Thomas J On
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Irakliy Abramov
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Lena Mary Houlihan
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Redi Rahmani
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Grant Koskay
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Sahin Hanalioglu
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Ali Tayebi Meybodi
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Michael T Lawton
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
- Robert F. Spetzler Chair in Neuroscience, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA
| | - Mark C Preul
- The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W Thomas Rd, Phoenix, AZ, 85013, USA.
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7
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Frigon EM, Gérin-Lajoie A, Dadar M, Boire D, Maranzano J. Comparison of histological procedures and antigenicity of human post-mortem brains fixed with solutions used in gross anatomy laboratories. Front Neuroanat 2024; 18:1372953. [PMID: 38659652 PMCID: PMC11039794 DOI: 10.3389/fnana.2024.1372953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
Background Brain banks provide small tissue samples to researchers, while gross anatomy laboratories could provide larger samples, including complete brains to neuroscientists. However, they are preserved with solutions appropriate for gross-dissection, different from the classic neutral-buffered formalin (NBF) used in brain banks. Our previous work in mice showed that two gross-anatomy laboratory solutions, a saturated-salt-solution (SSS) and an alcohol-formaldehyde-solution (AFS), preserve antigenicity of the main cellular markers (neurons, astrocytes, microglia, and myelin). Our goal is now to compare the quality of histology and antigenicity preservation of human brains fixed with NBF by immersion (practice of brain banks) vs. those fixed with a SSS and an AFS by whole body perfusion, practice of gross-anatomy laboratories. Methods We used a convenience sample of 42 brains (31 males, 11 females; 25-90 years old) fixed with NBF (N = 12), SSS (N = 13), and AFS (N = 17). One cm3 tissue blocks were cut, cryoprotected, frozen and sliced into 40 μm sections. The four cell populations were labeled using immunohistochemistry (Neurons = neuronal-nuclei = NeuN, astrocytes = glial-fibrillary-acidic-protein = GFAP, microglia = ionized-calcium-binding-adaptor-molecule1 = Iba1 and oligodendrocytes = myelin-proteolipid-protein = PLP). We qualitatively assessed antigenicity and cell distribution, and compared the ease of manipulation of the sections, the microscopic tissue quality, and the quality of common histochemical stains (e.g., Cresyl violet, Luxol fast blue, etc.) across solutions. Results Sections of SSS-fixed brains were more difficult to manipulate and showed poorer tissue quality than those from brains fixed with the other solutions. The four antigens were preserved, and cell labeling was more often homogeneous in AFS-fixed specimens. NeuN and GFAP were not always present in NBF and SSS samples. Some antigens were heterogeneously distributed in some specimens, independently of the fixative, but an antigen retrieval protocol successfully recovered them. Finally, the histochemical stains were of sufficient quality regardless of the fixative, although neurons were more often paler in SSS-fixed specimens. Conclusion Antigenicity was preserved in human brains fixed with solutions used in human gross-anatomy (albeit the poorer quality of SSS-fixed specimens). For some specific variables, histology quality was superior in AFS-fixed brains. Furthermore, we show the feasibility of frequently used histochemical stains. These results are promising for neuroscientists interested in using brain specimens from anatomy laboratories.
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Affiliation(s)
- Eve-Marie Frigon
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, QC, Canada
| | - Amy Gérin-Lajoie
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, QC, Canada
| | - Mahsa Dadar
- Department of Psychiatry, Douglas Research Center, McGill University, Montreal, QC, Canada
| | - Denis Boire
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, QC, Canada
| | - Josefina Maranzano
- Department of Anatomy, University of Quebec in Trois-Rivieres, Trois-Rivieres, QC, Canada
- Department of Neurology and Neurosurgery, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
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8
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Hade AC, Philips MA, Promet L, Jagomäe T, Hanumantharaju A, Salumäe L, Reimann E, Plaas M, Vasar E, Väli M. A cost-effective and efficient ex vivo, ex situ human whole brain perfusion protocol for immunohistochemistry. J Neurosci Methods 2024; 404:110059. [PMID: 38218387 DOI: 10.1016/j.jneumeth.2024.110059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/18/2023] [Accepted: 01/07/2024] [Indexed: 01/15/2024]
Abstract
BACKGROUND Chemical fixation of the brain can be executed through either the immersion method or the perfusion method. Perfusion fixation allows for better preservation of the brain tissue's ultrastructure, as it provides rapid and uniform delivery of the fixative to the tissue. Still, not all facilities have the expertise to perform perfusion fixation, with initial high cost and complexity of perfusion systems as the main factors limiting its widespread usage. NEW METHOD Here we present our low-cost approach of whole brain ex situ perfusion fixation to overcome the aforementioned limitations. Our self-made perfusion system, constructed utilising commercially accessible and affordable medical resources alongside laboratory and everyday items, demonstrates the capability to generate superior histological stainings of brain tissue. The perfused tissue can be stored prior to proceeding with IHC for at least one year. RESULTS Our method yielded high-quality results in histological stainings using both free-floating cryosections and paraffin-embedded tissue sections. The system is fully reusable and complies with the principles of sustainable management. COMPARISON WITH EXISTING METHODS Our whole brain perfusion system has been assembled from simple components and is able to achieve a linear flow with a pressure of 70 mmHg corresponding to the perfusion pressure of the brain. CONCLUSIONS Our ex situ method can be especially useful in research settings where expensive perfusion systems are not affordable or in any field with high time pressure, making it suitable for the field of forensic medicine or pathology in general.
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Affiliation(s)
- Andreas-Christian Hade
- Department of Pathological Anatomy and Forensic Medicine, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia; Estonian Forensic Science Institute, Tervise 20, Tallinn, Estonia
| | - Mari-Anne Philips
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia; Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia.
| | - Liisi Promet
- International Max Planck Research School for Neurosciences, University of Göttingen, Göttingen, Germany
| | - Toomas Jagomäe
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia; Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Arpana Hanumantharaju
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia; Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Liis Salumäe
- Pathology Service, Tartu University Hospital; Tartu, Estonia
| | - Ene Reimann
- Estonian Genome Centre, Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Mario Plaas
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia; Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Eero Vasar
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia; Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Marika Väli
- Department of Pathological Anatomy and Forensic Medicine, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia; Estonian Forensic Science Institute, Tervise 20, Tallinn, Estonia
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9
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Saito N, Hirai N, Koyahara Y, Sato S, Hiramoto Y, Fujita S, Nakayama H, Hayashi M, Ito K, Iwabuchi S. Comparative Study of Postmortem MRI and Pathological Findings in Malignant Brain Tumors. Cureus 2024; 16:e56241. [PMID: 38618299 PMCID: PMC11016320 DOI: 10.7759/cureus.56241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2024] [Indexed: 04/16/2024] Open
Abstract
This study compared magnetic resonance imaging (MRI) findings of postmortem brain specimens with neuropathological findings to evaluate the value of postmortem MRI. Postmortem MRI was performed on five formalin-fixed whole brains with malignant tumors. Postmortem T2-weighted images detected all neuropathological abnormalities as high-signal regions but also showed histological tumor invasion in areas without edema. Tumor lesions with high necrosis and edema showed high signal intensity on T2-weighted images; in three cases, lesion enlargement was detected on the final prenatal imaging and postmortem MRI. Disease progression immediately before death may have contributed to this difference. In conclusion, the correlation between MRI and neuropathological findings facilitates understanding of the mechanisms responsible for MRI abnormalities. Increased free water due to edema, necrosis, and brain tissue injury can explain the increased signal intensity observed on T2-weighted images. Postmortem MRI may contribute to effective pathology by identifying subtle abnormalities prior to brain dissection.
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Affiliation(s)
- Norihiko Saito
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Nozomi Hirai
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Yuki Koyahara
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Sho Sato
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Yu Hiramoto
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Satoshi Fujita
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Haruo Nakayama
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Morito Hayashi
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
| | - Keisuke Ito
- Neurosurgery, Toho University Ohashi Medical Center, Tokyo, JPN
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10
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Faigle W, Piccirelli M, Hortobágyi T, Frontzek K, Cannon AE, Zürrer WE, Granberg T, Kulcsar Z, Ludersdorfer T, Frauenknecht KBM, Reimann R, Ineichen BV. The Brainbox -a tool to facilitate correlation of brain magnetic resonance imaging features to histopathology. Brain Commun 2023; 5:fcad307. [PMID: 38025281 PMCID: PMC10664401 DOI: 10.1093/braincomms/fcad307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/20/2023] [Accepted: 11/07/2023] [Indexed: 12/01/2023] Open
Abstract
Magnetic resonance imaging (MRI) has limitations in identifying underlying tissue pathology, which is relevant for neurological diseases such as multiple sclerosis, stroke or brain tumours. However, there are no standardized methods for correlating MRI features with histopathology. Thus, here we aimed to develop and validate a tool that can facilitate the correlation of brain MRI features to corresponding histopathology. For this, we designed the Brainbox, a waterproof and MRI-compatible 3D printed container with an integrated 3D coordinate system. We used the Brainbox to acquire post-mortem ex vivo MRI of eight human brains, fresh and formalin-fixed, and correlated focal imaging features to histopathology using the built-in 3D coordinate system. With its built-in 3D coordinate system, the Brainbox allowed correlation of MRI features to corresponding tissue substrates. The Brainbox was used to correlate different MR image features of interest to the respective tissue substrate, including normal anatomical structures such as the hippocampus or perivascular spaces, as well as a lacunar stroke. Brain volume decreased upon fixation by 7% (P = 0.01). The Brainbox enabled degassing of specimens before scanning, reducing susceptibility artefacts and minimizing bulk motion during scanning. In conclusion, our proof-of-principle experiments demonstrate the usability of the Brainbox, which can contribute to improving the specificity of MRI and the standardization of the correlation between post-mortem ex vivo human brain MRI and histopathology. Brainboxes are available upon request from our institution.
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Affiliation(s)
- Wolfgang Faigle
- Neuroimmunology and MS Research Section, Neurology Clinic, University Zurich, University Hospital Zurich, CH-8091 Zurich, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland
| | - Tibor Hortobágyi
- Institute of Neuropathology, University of Zurich, CH-8091 Zurich, Switzerland
| | - Karl Frontzek
- Institute of Neuropathology, University of Zurich, CH-8091 Zurich, Switzerland
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, WC1N 1PJ London, United Kingdom
| | - Amelia Elaine Cannon
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland
| | - Wolfgang Emanuel Zürrer
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland
| | - Tobias Granberg
- Department of Neuroradiology, Karolinska University Hospital, S-141 86 Stockholm, Sweden
| | - Zsolt Kulcsar
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland
| | - Thomas Ludersdorfer
- Neuroimmunology and MS Research Section, Neurology Clinic, University Zurich, University Hospital Zurich, CH-8091 Zurich, Switzerland
| | - Katrin B M Frauenknecht
- Institute of Neuropathology, University of Zurich, CH-8091 Zurich, Switzerland
- Luxembourg Center of Neuropathology (LCNP), Laboratoire National de Santé, 3555 Dudelange, Luxembourg
- National Center of Pathology (NCP), Laboratoire National de Santé, 3555 Dudelange, Luxembourg
| | - Regina Reimann
- Institute of Neuropathology, University of Zurich, CH-8091 Zurich, Switzerland
| | - Benjamin Victor Ineichen
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, CH-8091 Zurich, Switzerland
- Center for Reproducible Science, University of Zurich, CH-8001 Zurich, Switzerland
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11
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Cho H, Han S, Cho HJ. Empirical relationship between TEM-derived myelin volume fraction and MRI-R 2 values in aging ex vivo rat corpus callosum. Magn Reson Imaging 2023; 103:75-83. [PMID: 37451521 DOI: 10.1016/j.mri.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/26/2023] [Accepted: 07/09/2023] [Indexed: 07/18/2023]
Abstract
Ex vivo ratiometric measurements of short- and long-T2 components using the multiple spin echo sequence of MRI are often employed to evaluate alterations in myelin content in the white matter (WM) of the brain. However, the relationship between absolute MRI-T2 values (long-T2 component) and myelin volumetric information in aged ex vivo rodent WM appears to be influenced by factors such as animal species, field strength, and fixation durations/washing. Here, multiple spin echo sequence-based MRI-R2 (the reciprocal of T2) values were measured in the corpus callosum (CC) region in the post-mortem rat brains (n = 9) of different age groups with common fixation techniques without washing at 7 T. Transmission electron microscopy (TEM)-based quantification of myelin volume fraction (MVF) and corresponding Monte-Carlo simulation to estimate relaxation rates (R2,IE) due to diffusion in the presence of inhomogeneous magnetic field perturbation in intra- and extra-cellular (IE) spaces were respectively performed. To determine whether the short-T2 components originating from myelin water were mixed with long-T2 components from IE water or were undetectable, the MVF values obtained from TEM results were respectively compared with MRI-R2 and R2,IE values. A significant correlation (Pearson's correlation coefficient r = 0.8763; p < 0.01) of average MRI-R2 and MVF values was observed. Estimated R2,IE values from Monte-Carlo simulations in IE water signals were also positively correlated (r = 0.8281; p < 0.01) with MVF values. However, the magnitudes of R2,IE values were much smaller than those observed for MRI-R2 values, indicating that changes in R2 related MVF are likely dominated by myelin water components. Such comparisons between independent parameters from MRI, TEM, and simulations support the suggestion that myelin water signals were indistinguishably mixed to exhibit mono-exponential T2 relaxation, and multiple spin echo sequence-based MRI-R2 values in aging ex vivo rat CC without prolonged washing still reflect the volumetric information of myelin, likely due to enhanced water exchange across the myelin.
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Affiliation(s)
- Hwapyeong Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Sohyun Han
- Research Equipment Operations Division, Korea Basic Science Institute, Cheongju, South Korea.
| | - Hyung Joon Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
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12
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Josemans SH, van der Post AS, Strijkers GJ, Dawood Y, van den Hoff MJB, Jens SRJ, Obdeijn MC, Oostra RJ, Maas M. Ultra-high-field MRI of postmortem human fetal wrist joints: initial experience. Eur Radiol Exp 2023; 7:28. [PMID: 37271766 DOI: 10.1186/s41747-023-00341-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/31/2023] [Indexed: 06/06/2023] Open
Abstract
BACKGROUND This study aimed to assess the feasibility of postmortem ultra-high-field magnetic resonance imaging (UHF-MRI) to study fetal musculoskeletal anatomy and explore the contribution of variation in iodine and formaldehyde (paraformaldehyde, PFA) treatment of tissue. METHODS Seven upper extremities from human fetuses with gestational ages of 19 to 24 weeks were included in this experimental study, approved by the Medical Research Ethics Committee. The specimens were treated with various storage (0.2-4% PFA) and staining (Lugol's solution) protocols and the wrist joint was subsequently imaged with 7.0 T UHF-MRI. Soft-tissue contrast was quantified by determining regions of interest within a chondrified carpal bone (CCB) from the proximal row, the triangular fibrocartilage (TFC), and the pronator quadratus muscle (PQM) and calculating the contrast ratios (CRs) between mean signal intensities of CCB to TFC and CCB to PQM. RESULTS UHF-MRI showed excellent soft-tissue contrast in different musculoskeletal tissues. Increasing storage time in 4% PFA, CRs decreased, resulting in a shift from relatively hyperintense to hypointense identification of the CCB. Storage in 0.2% PFA barely influenced the CRs over time. Lugol's solution caused an increase in CRs and might have even contributed to the inversion of the CRs. CONCLUSIONS UHF-MRI is a feasible technique to image musculoskeletal structures in fetal upper extremities and most successful after short storage in 4% PFA or prolonged storage in 0.2% PFA. The use of Lugol's solution is not detrimental on soft-tissue MRI contrast and therefore enables effectively combining UHF-MRI with contrast-enhanced micro-computed tomography using a single preparation of the specimen. RELEVANCE STATEMENT UHF-MRI can be performed after CE-micro-CT to take advantage of both techniques. KEY POINTS • UHF-MRI is feasible to study human fetal cartilaginous and ligamentous anatomy. • Storage in low PFA concentrations (i.e., 0.2%) improves soft-tissue contrast in UHF-MRI. • Limited preservation time in high concentrations of PFA improves soft-tissue contrast in UHF-MRI. • Prior staining with Lugol's solution does not reduce soft-tissue contrast in UHF-MRI.
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Affiliation(s)
- Sabine H Josemans
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Anne-Sophie van der Post
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
- Sports and Musculoskeletal Health, Amsterdam Movement Sciences, Amsterdam, The Netherlands.
| | - Gustav J Strijkers
- Biomedical Engineering and Physics, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Yousif Dawood
- Medical Biology, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | | | - Sjoerd R J Jens
- Radiology and Nuclear Medicine, Rijnstate Hospital, Arnhem, The Netherlands
| | - Miryam C Obdeijn
- Plastic, Reconstructive and Hand Surgery, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Roelof-Jan Oostra
- Medical Biology, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Mario Maas
- Department of Radiology and Nuclear Medicine, Amsterdam UMC Location University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Sports and Musculoskeletal Health, Amsterdam Movement Sciences, Amsterdam, The Netherlands
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13
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Uchida Y, Onda K, Hou Z, Troncoso JC, Mori S, Oishi K. Microstructural Neurodegeneration of the Entorhinal-Hippocampus Pathway along the Alzheimer's Disease Continuum. J Alzheimers Dis 2023; 95:1107-1117. [PMID: 37638442 PMCID: PMC10578220 DOI: 10.3233/jad-230452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2023] [Indexed: 08/29/2023]
Abstract
BACKGROUND Conventional neuroimaging biomarkers for the neurodegeneration of Alzheimer's disease (AD) are not sensitive enough to detect neurodegenerative alterations during the preclinical stage of AD individuals. OBJECTIVE We examined whether neurodegeneration of the entorhinal-hippocampal pathway could be detected along the AD continuum using ultra-high-field diffusion tensor imaging and tractography for ex vivo brain tissues. METHODS Postmortem brain specimens from a cognitively unimpaired individual without AD pathological changes (non-AD), a cognitively unimpaired individual with AD pathological changes (preclinical AD), and a demented individual with AD pathological changes (AD dementia) were scanned with an 11.7T diffusion magnetic resonance imaging. Fractional anisotropy (FA) values of the entorhinal layer II and number of perforant path fibers counted by tractography were compared among the AD continuum. Following the imaging analyses, the status of myelinated fibers and neuronal cells were verified by subsequent serial histological examinations. RESULTS At 250μm (zipped to 125μm) isotropic resolution, the entorhinal layer II islands and the perforant path fibers could be identified in non-AD and preclinical AD, but not in AD dementia, followed by histological verification. The FA value of the entorhinal layer II was the highest among the entorhinal laminae in non-AD and preclinical AD, whereas the FA values in the entorhinal laminae were homogeneously low in AD dementia. The FA values and number of perforant path fibers decreased along the AD continuum (non-AD>preclinical AD > AD dementia). CONCLUSION We successfully detected neurodegenerative alterations of the entorhinal-hippocampal pathway at the preclinical stage of the AD continuum.
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Affiliation(s)
- Yuto Uchida
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kengo Onda
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zhipeng Hou
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Juan C. Troncoso
- Department of Pathology, Division of Neuropathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Susumu Mori
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kenichi Oishi
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- The Richman Family Precision Medicine Center of Excellence in Alzheimer’s Disease, Baltimore, MD, USA
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14
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Luo J, Collingwood JF. Effective R 2 relaxation rate, derived from dual-contrast fast-spin-echo MRI, enables detection of hemisphere differences in iron level and dopamine function in Parkinson's disease and healthy individuals. J Neurosci Methods 2022; 382:109708. [PMID: 36089168 DOI: 10.1016/j.jneumeth.2022.109708] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/26/2022] [Accepted: 09/06/2022] [Indexed: 01/05/2023]
Abstract
BACKGROUND Clinical estimates of brain iron concentration are achievable with quantitative transverse relaxation rate R2, via time-consuming multiple spin-echo (SE) sequences. The objective of this study was to investigate whether quantitative iron-sensitive information may be derived from 3.0 T dual-contrast fast-spin-echo (FSE) sequences (typically employed in anatomical non-quantitative evaluations), as a routinely-collected alternative to evaluate iron levels in healthy (HC) and Parkinson's disease (PD) brains. NEW METHOD MRI 3.0 T FSE data from the Parkinson's Progression Markers Initiative (PPMI) (12 PD, 12 age- and gender-matched HC subjects) were cross-sectionally and longitudinally evaluated. A new measure, 'effective R2', was calculated for bilateral subcortical grey matter (caudate nucleus, putamen, globus pallidus, red nucleus, substantia nigra). Linear regression analysis was performed to correlate 'effective R2' with models of age-dependent brain iron concentration and striatal dopamine transporter (DaT) receptor binding ratio. RESULTS Effective R2 was strongly correlated with estimated brain iron concentration. In PD, putaminal effective R2 difference was observed between the hemispheres contra-/ipsi-lateral to the predominantly symptomatic side at onset. This hemispheric difference was correlated with the putaminal DaT binding ratios in PD. COMPARISON WITH EXISTING METHOD(S) Effective R2, derived from rapid dual-contrast FSE sequences, showed viability as an alternative to R2 from SE sequences. Linear correlation of effective R2 with estimated iron concentration was comparable to documented iron-dependent R2. The effective R2 correlation coefficient was consistent with theoretical R2 iron-dependence at 3.0 T. CONCLUSIONS Effective R2 has clinical potential as a fast quantitative method, as an alternative to R2, to aid evaluation of brain iron levels and DaT function.
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Affiliation(s)
- Jierong Luo
- School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
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15
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Frigon EM, Dadar M, Boire D, Maranzano J. Antigenicity is preserved with fixative solutions used in human gross anatomy: A mice brain immunohistochemistry study. Front Neuroanat 2022; 16:957358. [DOI: 10.3389/fnana.2022.957358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/16/2022] [Indexed: 11/13/2022] Open
Abstract
BackgroundHistology remains the gold-standard to assess human brain biology, so ex vivo studies using tissue from brain banks are standard practice in neuroscientific research. However, a larger number of specimens could be obtained from gross anatomy laboratories. These specimens are fixed with solutions appropriate for dissections, but whether they also preserve brain tissue antigenicity is unclear. Therefore, we perfused mice brains with solutions used for human body preservation to assess and compare the tissue quality and antigenicity of the main cell populations.Materials and methodsTwenty-eight C57BL/6J mice were perfused with 4% formaldehyde (FAS, N = 9), salt-saturated solution (SSS, N = 9), and alcohol solution (AS, N = 10). The brains were cut into 40 μm sections for antigenicity analysis and were assessed by immunohistochemistry of four antigens: neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP astrocytes), ionized calcium-binding adaptor molecule 1 (Iba1-microglia), and myelin proteolipid protein (PLP). We compared the fixatives according to multiple variables: perfusion quality, ease of manipulation, tissue quality, immunohistochemistry quality, and antigenicity preservation.ResultsThe perfusion quality was better using FAS and worse using AS. The manipulation was very poor in SSS brains. FAS- and AS-fixed brains showed higher tissue and immunohistochemistry quality than the SSS brains. All antigens were readily observed in every specimen, regardless of the fixative solution.ConclusionSolutions designed to preserve specimens for human gross anatomy dissections also preserve tissue antigenicity in different brain cells. This offers opportunities for the use of human brains fixed in gross anatomy laboratories to assess normal or pathological conditions.
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16
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Tazwar M, Evia AM, Tamhane AA, Ridwan AR, Leurgans SE, Bennett DA, Schneider JA, Arfanakis K. Limbic-predominant age-related TDP-43 encephalopathy neuropathological change (LATE-NC) is associated with lower R 2 relaxation rate: an ex-vivo MRI and pathology investigation. Neurobiol Aging 2022; 117:128-138. [PMID: 35728463 PMCID: PMC9667705 DOI: 10.1016/j.neurobiolaging.2022.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 05/04/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022]
Abstract
Limbic predominant age-related transactive response DNA binding protein 43 (TDP-43) encephalopathy neuropathological change (LATE-NC) is common in persons older than 80 years of age and is associated with cognitive decline and increased likelihood of dementia. The MRI signature of LATE-NC has not been fully determined. In this study, the association of LATE-NC with the transverse relaxation rate, R2, was investigated in a large number of community-based older adults. Cerebral hemispheres from 738 participants of the Rush Memory and Aging Project, Religious Orders Study, and Minority Aging Research Study, were imaged ex-vivo with multi-echo spin-echo MRI and underwent detailed neuropathologic examination. Voxel-wise analysis revealed a novel spatial pattern of lower R2 for higher LATE-NC stage, controlling for other neuropathologies and demographics. This pattern was consistent with the distribution of LATE-NC in gray matter, and also involved white matter providing temporo-temporal, fronto-temporal, and temporo-basal ganglia connectivity. Furthermore, analysis at different LATE-NC stages showed that R2 imaging may capture the general progression of LATE-NC, but only when TDP-43 inclusions extend beyond the amygdala.
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Affiliation(s)
- Mahir Tazwar
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Arnold M Evia
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Ashish A Tamhane
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Abdur Raquib Ridwan
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Sue E Leurgans
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA; Department of Pathology, Rush University Medical Center, Chicago, IL, USA
| | - Konstantinos Arfanakis
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA; Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Diagnostic Radiology, Rush University Medical Center, Chicago, IL, USA.
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17
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Parallel gold enhancement of quantum dots 565/655 for double-labelling correlative light and electron microscopy on human autopsied samples. Sci Rep 2022; 12:6113. [PMID: 35413968 PMCID: PMC9005520 DOI: 10.1038/s41598-022-09849-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 03/23/2022] [Indexed: 11/24/2022] Open
Abstract
Cadmium selenide quantum dots (QDs) are fluorescent and electron-dense nanoparticles. When used as reporter of immunolabeling, this dual visibility is essential for direct comparison of its fluorescent signals on light microscopy (LM) and their ultrastructrual counterparts on electron microscopy (EM) as correlative light and electron microscopy (CLEM). To facilitate EM recognition, QDs on EM grid were gold enhanced, which increased their size and electron density. On histological sections as well, gold-enhanced QDs, used as a reporter of immunolabeling, were easily recognized on EM. Because target structures are visible on bright field microscopy, gold enhancement facilitated trimming the target structures into final EM sections. Furthermore, gold enhancement of rod-shaped QD655 on EM grid was accentuated on their tips while spherical QD565 was gold-enhanced as sphere in contrast. This EM distinction was evident on histological sections where QD565 (green fluorescence) and QD655 (red fluorescence) were used as a reporter pair for double immunolabeling. Double-labeled immuno-fluorescent images, initially captured before EM processing, are now compared with their respective immuno EM counterparts. Specific labeling of each epitope was corroborated by mutual comparison between LM and EM. Although fluoronanogold may be a candidate reporter partner with QDs for gold-enhanced, double-labeling CLEM, its limited penetration into fixed tissue hampers universal use for thick histological sections. Gold-enhancement of QD immunolabeling, now expanded to double-labeling CLEM for human brain samples, will pave the way to translate molecular events into ultrastructural morphopathogenesis in situ.
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18
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Chan KS, Hédouin R, Mollink J, Schulz J, van Cappellen van Walsum AM, Marques JP. Imaging white matter microstructure with gradient-echo phase imaging: Is ex vivo imaging with formalin-fixed tissue a good approximation of the in vivo brain? Magn Reson Med 2022; 88:380-390. [PMID: 35344591 PMCID: PMC9314807 DOI: 10.1002/mrm.29213] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 01/17/2022] [Accepted: 02/10/2022] [Indexed: 11/20/2022]
Abstract
Purpose Ex vivo imaging is a commonly used approach to investigate the biophysical mechanism of orientation‐dependent signal phase evolution in white matter. Yet, how phase measurements are influenced by the structural alteration in the tissue after formalin fixation is not fully understood. Here, we study the effects on magnetic susceptibility, microstructural compartmentalization, and chemical exchange measurement with a postmortem formalin‐fixed whole‐brain human tissue. Methods A formalin‐fixed, postmortem human brain specimen was scanned with multiple orientations to the main magnetic field direction for robust bulk magnetic susceptibility measurement with conventional quantitative susceptibility imaging models. White matter samples were subsequently excised from the whole‐brain specimen and scanned in multiple rotations on an MRI scanner to measure the anisotropic magnetic susceptibility and microstructure‐related contributions in the signal phase and to validate the findings of the whole‐brain data. Results The bulk isotropic magnetic susceptibility of ex vivo whole‐brain imaging is comparable to in vivo imaging, with noticeable enhanced nonsusceptibility contributions. The excised specimen experiment reveals that anisotropic magnetic susceptibility and compartmentalization phase effect were considerably reduced in the formalin‐fixed white matter specimens. Conclusions Formalin‐fixed postmortem white matter exhibits comparable isotropic magnetic susceptibility to previous in vivo imaging findings. However, the measured phase and magnitude data of the fixed white matter tissue shows a significantly weaker orientation dependency and compartmentalization effect. Alternatives to formalin fixation are needed to better reproduce the in vivo microstructural effects in postmortem samples.
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Affiliation(s)
- Kwok-Shing Chan
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Renaud Hédouin
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands.,Empenn, INRIA, INSERM, CNRS, Université de Rennes 1, Rennes, France
| | - Jeroen Mollink
- Department of Medical Imaging, Anatomy, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jenni Schulz
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Anne-Marie van Cappellen van Walsum
- Department of Medical Imaging, Anatomy, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - José P Marques
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
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19
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Tendler BC, Hanayik T, Ansorge O, Bangerter-Christensen S, Berns GS, Bertelsen MF, Bryant KL, Foxley S, van den Heuvel MP, Howard AFD, Huszar IN, Khrapitchev AA, Leonte A, Manger PR, Menke RAL, Mollink J, Mortimer D, Pallebage-Gamarallage M, Roumazeilles L, Sallet J, Scholtens LH, Scott C, Smart A, Turner MR, Wang C, Jbabdi S, Mars RB, Miller KL. The Digital Brain Bank, an open access platform for post-mortem imaging datasets. eLife 2022; 11:e73153. [PMID: 35297760 PMCID: PMC9042233 DOI: 10.7554/elife.73153] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 03/17/2022] [Indexed: 11/13/2022] Open
Abstract
Post-mortem magnetic resonance imaging (MRI) provides the opportunity to acquire high-resolution datasets to investigate neuroanatomy and validate the origins of image contrast through microscopy comparisons. We introduce the Digital Brain Bank (open.win.ox.ac.uk/DigitalBrainBank), a data release platform providing open access to curated, multimodal post-mortem neuroimaging datasets. Datasets span three themes-Digital Neuroanatomist: datasets for detailed neuroanatomical investigations; Digital Brain Zoo: datasets for comparative neuroanatomy; and Digital Pathologist: datasets for neuropathology investigations. The first Digital Brain Bank data release includes 21 distinctive whole-brain diffusion MRI datasets for structural connectivity investigations, alongside microscopy and complementary MRI modalities. This includes one of the highest-resolution whole-brain human diffusion MRI datasets ever acquired, whole-brain diffusion MRI in fourteen nonhuman primate species, and one of the largest post-mortem whole-brain cohort imaging studies in neurodegeneration. The Digital Brain Bank is the culmination of our lab's investment into post-mortem MRI methodology and MRI-microscopy analysis techniques. This manuscript provides a detailed overview of our work with post-mortem imaging to date, including the development of diffusion MRI methods to image large post-mortem samples, including whole, human brains. Taken together, the Digital Brain Bank provides cross-scale, cross-species datasets facilitating the incorporation of post-mortem data into neuroimaging studies.
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Affiliation(s)
- Benjamin C Tendler
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Taylor Hanayik
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Olaf Ansorge
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Sarah Bangerter-Christensen
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | | | - Mads F Bertelsen
- Centre for Zoo and Wild Animal Health, Copenhagen ZooFrederiksbergDenmark
| | - Katherine L Bryant
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Sean Foxley
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
- Department of Radiology, University of ChicagoChicagoUnited States
| | - Martijn P van den Heuvel
- Department of Complex Trait Genetics, Centre for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit AmsterdamAmsterdamNetherlands
- Department of Child Psychiatry, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit AmsterdamAmsterdamNetherlands
| | - Amy FD Howard
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Istvan N Huszar
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Alexandre A Khrapitchev
- Medical Research Council Oxford Institute for Radiation Oncology, University of OxfordOxfordUnited Kingdom
| | - Anna Leonte
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the WitwatersrandJohannesburgSouth Africa
| | - Ricarda AL Menke
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Jeroen Mollink
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Duncan Mortimer
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Menuka Pallebage-Gamarallage
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Lea Roumazeilles
- Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of OxfordOxfordUnited Kingdom
| | - Jerome Sallet
- Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of OxfordOxfordUnited Kingdom
- Stem Cell and Brain Research Institute, Université Lyon 1, INSERMBronFrance
| | - Lianne H Scholtens
- Department of Complex Trait Genetics, Centre for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit AmsterdamAmsterdamNetherlands
| | - Connor Scott
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Adele Smart
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Martin R Turner
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
- Division of Clinical Neurology, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Chaoyue Wang
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Saad Jbabdi
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
| | - Rogier B Mars
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
- Donders Institute for Brain, Cognition and Behaviour, Radboud University NijmegenNijmegenNetherlands
| | - Karla L Miller
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of OxfordOxfordUnited Kingdom
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20
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Tasaki S, Xu J, Avey DR, Johnson L, Petyuk VA, Dawe RJ, Bennett DA, Wang Y, Gaiteri C. Inferring protein expression changes from mRNA in Alzheimer's dementia using deep neural networks. Nat Commun 2022; 13:655. [PMID: 35115553 PMCID: PMC8814036 DOI: 10.1038/s41467-022-28280-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 01/19/2022] [Indexed: 12/30/2022] Open
Abstract
Identifying the molecular systems and proteins that modify the progression of Alzheimer's disease and related dementias (ADRD) is central to drug target selection. However, discordance between mRNA and protein abundance, and the scarcity of proteomic data, has limited our ability to advance candidate targets that are mainly based on gene expression. Therefore, by using a deep neural network that predicts protein abundance from mRNA expression, here we attempt to track the early protein drivers of ADRD. Specifically, by applying the clei2block deep learning model to 1192 brain RNA-seq samples, we identify protein modules and disease-associated expression changes that were not directly observed at the mRNA level. Moreover, pseudo-temporal trajectory inference based on the predicted proteome became more closely correlated with cognitive decline and hippocampal atrophy compared to RNA-based trajectories. This suggests that the predicted changes in protein expression could provide a better molecular representation of ADRD progression. Furthermore, overlaying clinical traits on protein pseudotime trajectory identifies protein modules altered before cognitive impairment. These results demonstrate how our method can be used to identify potential early protein drivers and possible drug targets for treating and/or preventing ADRD.
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Affiliation(s)
- Shinya Tasaki
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.
| | - Jishu Xu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Denis R Avey
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Lynnaun Johnson
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Vladislav A Petyuk
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Robert J Dawe
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Yanling Wang
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Chris Gaiteri
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
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21
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van Veluw SJ, Arfanakis K, Schneider JA. Neuropathology of Vascular Brain Health: Insights From Ex Vivo Magnetic Resonance Imaging-Histopathology Studies in Cerebral Small Vessel Disease. Stroke 2022; 53:404-415. [PMID: 35000425 PMCID: PMC8830602 DOI: 10.1161/strokeaha.121.032608] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Sporadic cerebral small vessel disease (SVD) is a major contributor to vascular cognitive impairment and dementia in the aging human brain. On neuropathology, sporadic SVD is characterized by abnormalities to the small vessels of the brain predominantly in the form of cerebral amyloid angiopathy and arteriolosclerosis. These pathologies frequently coexist with Alzheimer disease changes, such as plaques and tangles, in a single brain. Conversely, during life, magnetic resonance imaging (MRI) only captures the larger manifestations of SVD in the form of parenchymal brain abnormalities. There appears to be a major knowledge gap regarding the underlying neuropathology of individual MRI-detectable SVD abnormalities. Ex vivo MRI in postmortem human brain tissue is a powerful tool to bridge this gap. This review summarizes current insights into the histopathologic correlations of MRI manifestations of SVD, their underlying cause, presumed pathophysiology, and associated secondary tissue injury. Moreover, we discuss the advantages and limitations of ex vivo MRI-guided histopathologic investigations and make recommendations for future studies.
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Affiliation(s)
- Susanne J. van Veluw
- J. Philip Kistler Stroke Research Center, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA,MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Charlestown, MA, USA,Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Konstantinos Arfanakis
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA,Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Julie A. Schneider
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA,Departments of Pathology and Neurological Sciences, Rush University Medical Center, Chicago IL, USA
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22
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Moon BF, Iyer SK, Josselyn NJ, Hwuang E, Swago S, Keeney SJ, Castillero E, Ferrari G, Pilla JJ, Gorman JH, Gorman RC, Tschabrunn C, Shou H, Matthai W, Wehrli FW, Ferrari VA, Han Y, Litt H, Witschey WR. Magnetic susceptibility and R2* of myocardial reperfusion injury at 3T and 7T. Magn Reson Med 2022; 87:323-336. [PMID: 34355815 PMCID: PMC9067599 DOI: 10.1002/mrm.28955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/15/2021] [Accepted: 07/17/2021] [Indexed: 01/03/2023]
Abstract
PURPOSE Magnetic susceptibility (Δχ) alterations have shown association with myocardial infarction (MI) iron deposition, yet there remains limited understanding of the relationship between relaxation rates and susceptibility or the effect of magnetic field strength. Hence, Δχ and R 2 ∗ in MI were compared at 3T and 7T. METHODS Subacute MI was induced by coronary artery ligation in male Yorkshire swine. 3D multiecho gradient echo imaging was performed at 1-week postinfarction at 3T and 7T. Quantitative susceptibility mapping images were reconstructed using a morphology-enabled dipole inversion. R 2 ∗ maps and quantitative susceptibility mapping were generated to assess the relationship between R 2 ∗ , Δχ, and field strength. Infarct histopathology was investigated. RESULTS Magnetic susceptibility was not significantly different across field strengths (7T: 126.8 ± 41.7 ppb; 3T: 110.2 ± 21.0 ppb, P = NS), unlike R 2 ∗ (7T: 247.0 ± 14.8 Hz; 3T: 106.1 ± 6.5 Hz, P < .001). Additionally, infarct Δχ and R 2 ∗ were significantly higher than remote myocardium. Magnetic susceptibility at 7T versus 3T had a significant association (β = 1.02, R2 = 0.82, P < .001), as did R 2 ∗ (β = 2.35, R2 = 0.98, P < .001). Infarct pathophysiology and iron deposition were detected through histology and compared with imaging findings. CONCLUSION R 2 ∗ showed dependence and Δχ showed independence of field strength. Histology validated the presence of iron and supported imaging findings.
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Affiliation(s)
- Brianna F. Moon
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Srikant Kamesh Iyer
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nicholas J. Josselyn
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Eileen Hwuang
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Sophia Swago
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Samuel J. Keeney
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Estibaliz Castillero
- Department of Surgery, Columbia University Irving Medical Center, New York City, NY, USA
| | - Giovanni Ferrari
- Department of Surgery, Columbia University Irving Medical Center, New York City, NY, USA
| | - James J. Pilla
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph H. Gorman
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert C. Gorman
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Cory Tschabrunn
- Department of Medicine, Division of Cardiovascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Haochang Shou
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - William Matthai
- Department of Medicine, Penn Presbyterian Medical Center, University of Pennsylvania, Philadelphia, PA, USA
| | - Felix W. Wehrli
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Victor A. Ferrari
- Department of Medicine, Division of Cardiovascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yuchi Han
- Department of Medicine, Division of Cardiovascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Harold Litt
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Medicine, Division of Cardiovascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Walter R. Witschey
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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23
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Xiao J, Hornburg KJ, Cofer G, Cook JJ, Pratson F, Qi Y, Johnson GA. A time-course study of actively stained mouse brains: Diffusion tensor imaging parameters and connectomic stability over 1 year. NMR IN BIOMEDICINE 2022; 35:e4611. [PMID: 34558744 PMCID: PMC10461792 DOI: 10.1002/nbm.4611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 07/21/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
While the application of diffusion tensor imaging (DTI), tractography, and connectomics to fixed tissue is a common practice today, there have been limited studies examining the effects of fixation on brain microstructure over extended periods. This mouse model time-course study reports the changes of regional brain volumes and diffusion scalar parameters, such as fractional anisotropy, across 12 representative brain regions as measures of brain structural stability. The scalar DTI parameters and regional volumes were highly variable over the first 2 weeks after fixation. The same parameters were consistent over a 2-8-week window after fixation, which means confounds from tissue stability over that scanning window were minimal. Quantitative connectomes were analyzed over the same time with extension out to 1 year. While there was some change in the scalar metrics at 1 year after fixation, these changes were sufficiently small, particularly in white matter, to support reproducible connectomes over a period ranging from 2-weeks to 1-year post-fixation. These findings delineate a scanning period, during which brain volumes, diffusion scalar metrics, and connectomes are remarkably consistent.
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Affiliation(s)
- Jaclyn Xiao
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Kathryn J. Hornburg
- Duke Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Gary Cofer
- Duke Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
| | - James J. Cook
- Duke Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Forrest Pratson
- Duke Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Yi Qi
- Duke Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
| | - G. Allan Johnson
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
- Duke Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA
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24
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Nazemorroaya A, Aghaeifar A, Shiozawa T, Hirt B, Schulz H, Scheffler K, Hagberg GE. Developing formalin-based fixative agents for post mortem brain MRI at 9.4 T. Magn Reson Med 2021; 87:2481-2494. [PMID: 34931721 DOI: 10.1002/mrm.29122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 11/07/2022]
Abstract
PURPOSE To develop fixative agents for high-field MRI with suitable dielectric properties and measure MR properties in immersion-fixed brain tissue. METHODS Dielectric properties of formalin-based agents were assessed (100 MHz-4.5 GHz), and four candidate fixatives with/without polyvinylpyrrolidone (PVP) and different salt concentrations were formulated. B1 field and MR properties (T1 , R 2 ∗ , R2 , R 2 ' , and magnetic susceptibility [QSM]) were observed in white and gray matter of pig brain samples during 0.5-35 days of immersion fixation. The kinetics were fitted using exponential functions. The immersion time required to reach maximum R 2 ∗ values at different tissue depths was used to estimate the Medawar coefficient for fixative penetration. The effect of replacing the fixatives with Fluoroinert and phosphate-buffered saline as embedding media was also evaluated. RESULTS The dielectric properties of formalin were nonlinearly modified by increasing amounts of additives. With 5% PVP and 0.04% NaCl, the dielectric properties and B1 field reflected in vivo conditions. The highest B1 values were found in white matter with PVP and varied significantly with tissue depth and embedding media, but not with immersion time. The MR properties depended on PVP yielding lower T1 , higher R 2 ∗ , more paramagnetic QSM values, and a lower Medawar coefficient (0.9 mm / h ; without PVP: 1.5). Regardless of fixative, switching to phosphate-buffered saline as embedder caused a paramagnetic shift in QSM and decreased R 2 ∗ that progressed during 1 month of storage, whereas no differences were found with Fluorinert. CONCLUSION In vivo-like B1 fields can be achieved in formalin fixatives using PVP and a low salt concentration, yielding lower T1 , higher R 2 ∗ , and more paramagnetic QSM than without additives. The kinetics of R 2 ∗ allowed estimation of fixative tissue penetration.
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Affiliation(s)
- Azadeh Nazemorroaya
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Ali Aghaeifar
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Thomas Shiozawa
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karl's University of Tübingen, Tübingen, Germany
| | - Bernhard Hirt
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karl's University of Tübingen, Tübingen, Germany
| | - Hildegard Schulz
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Klaus Scheffler
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,Institute of Biomedical Magnetic Resonance, Eberhard Karl's University of Tübingen, Tübingen, Germany
| | - Gisela E Hagberg
- High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.,Institute of Biomedical Magnetic Resonance, Eberhard Karl's University of Tübingen, Tübingen, Germany
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25
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Tendler BC, Qi F, Foxley S, Pallebage-Gamarallage M, Menke RAL, Ansorge O, Hurley SA, Miller KL. A method to remove the influence of fixative concentration on postmortem T 2 maps using a kinetic tensor model. Hum Brain Mapp 2021; 42:5956-5972. [PMID: 34541735 PMCID: PMC8596944 DOI: 10.1002/hbm.25661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 08/06/2021] [Accepted: 08/30/2021] [Indexed: 12/20/2022] Open
Abstract
Formalin fixation has been shown to substantially reduce T2 estimates, primarily driven by the presence of fixative in tissue. Prior to scanning, post‐mortem samples are often placed into a fluid that has more favourable imaging properties. This study investigates whether there is evidence for a change in T2 in regions close to the tissue surface due to fixative outflux into this surrounding fluid. Furthermore, we investigate whether a simulated spatial map of fixative concentration can be used as a confound regressor to reduce T2 inhomogeneity. To achieve this, T2 maps and diffusion tensor estimates were obtained in 14 whole, formalin‐fixed post‐mortem brains placed in Fluorinert approximately 48 hr prior to scanning. Seven brains were fixed with 10% formalin and seven brains were fixed with 10% neutral buffered formalin (NBF). Fixative outflux was modelled using a proposed kinetic tensor (KT) model, which incorporates voxelwise diffusion tensor estimates to account for diffusion anisotropy and tissue‐specific diffusion coefficients. Brains fixed with 10% NBF revealed a spatial T2 pattern consistent with modelled fixative outflux. Confound regression of fixative concentration reduced T2 inhomogeneity across both white and grey matter, with the greatest reduction attributed to the KT model versus simpler models of fixative outflux. No such effect was observed in brains fixed with 10% formalin. Correlations between the transverse relaxation rate R2 and ferritin/myelin proteolipid protein (PLP) histology lead to an increased similarity for the relationship between R2 and PLP for the two fixative types after KT correction.
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Affiliation(s)
- Benjamin C Tendler
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford
| | - Feng Qi
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford
| | - Sean Foxley
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford.,Department of Radiology, University of Chicago, Chicago, Illinois, USA
| | | | - Ricarda A L Menke
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford
| | - Olaf Ansorge
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Samuel A Hurley
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford.,Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Karla L Miller
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford
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26
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The effect of beta-amyloid and tau protein aggregations on magnetic susceptibility of anterior hippocampal laminae in Alzheimer's diseases. Neuroimage 2021; 244:118584. [PMID: 34537383 DOI: 10.1016/j.neuroimage.2021.118584] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/27/2021] [Accepted: 09/15/2021] [Indexed: 11/20/2022] Open
Abstract
Previous studies have reported the changes of magnetic susceptibility induced by iron deposition in hippocampus of Alzheimer's disease (AD) brains. It is well-known that hippocampus is divided into well-defined laminar architecture, which, however, is difficult to be resolved with in-vivo MRI due to the limited imaging resolution. The present study aims to investigate layer-specific magnetic susceptibility in the hippocampus of AD patients using high-resolution ex-vivo MRI, and elucidate its relationship with beta amyloid (Aβ) and tau protein histology. We performed quantitative susceptibility mapping (QSM) and T2* mapping on postmortem anterior hippocampus samples from four AD, four Primary Age-Related Tauopathy (PART), and three control brains. We manually segmented each sample into seven layers, including four layers in the cornu ammonis1 (CA1) and three layers in the dentate gyrus (DG), and then evaluated AD-related alterations of susceptibility and T2* values and their correlations with Aβ and tau in each hippocampal layer. Specifically, we found (1) layer-specific variations of susceptibility and T2* measurements in all samples; (2) the heterogeneity of susceptibility were higher in all layers of AD patients compared with the age- and gender-matched PART cases while the heterogeneity of T2* values were lower in four layers of CA1; and (3) voxel-wise MRI-histological correlation revealed both susceptibility and T2* values in the stratum molecular (SM) and stratum lacunosum (SL) layers were correlated with the Aβ content in AD, while the T2* values in the stratum radiatum (SR) layer were correlated with the tau content in the PART but not AD. These findings suggest a selective effect of the Aβ- and tau-pathology on the susceptibility and T2* values in the different layers of anterior hippocampus. Particularly, the alterations of magnetic susceptibility in the SM and SL layers may be associated with Aβ aggregation, while those in the SR layermay reflect the age-related tau protein aggregation.
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27
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Physical activity, brain tissue microstructure, and cognition in older adults. PLoS One 2021; 16:e0253484. [PMID: 34232955 PMCID: PMC8262790 DOI: 10.1371/journal.pone.0253484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 06/06/2021] [Indexed: 01/28/2023] Open
Abstract
Objective To test whether postmortem MRI captures brain tissue characteristics that mediate the association between physical activity and cognition in older adults. Methods Participants (N = 318) were older adults from the Rush Memory and Aging Project who wore a device to quantify physical activity and also underwent detailed cognitive and motor testing. Following death, cerebral hemispheres underwent MRI to quantify the transverse relaxation rate R2, a metric related to tissue microstructure. For analyses, we reduced the dimensionality of the R2 maps from approximately 500,000 voxels to 30 components using spatial independent component analysis (ICA). Via path analysis, we examined whether these R2 components attenuated the association between physical activity and cognition, controlling for motor abilities and indices of common brain pathologies. Results Two of the 30 R2 components were associated with both total daily physical activity and global cognition assessed proximate to death. We visualized these components by highlighting the clusters of voxels whose R2 values contributed most strongly to each. One of these spatial signatures spanned periventricular white matter and hippocampus, while the other encompassed white matter of the occipital lobe. These two R2 components partially mediated the association between physical activity and cognition, accounting for 12.7% of the relationship (p = .01). This mediation remained evident after controlling for motor abilities and neurodegenerative and vascular brain pathologies. Conclusion The association between physically activity and cognition in older adults is partially accounted for by MRI-based signatures of brain tissue microstructure. Further studies are needed to elucidate the molecular mechanisms underlying this pathway.
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Humphreys CA, Smith C, Wardlaw JM. Correlations in post-mortem imaging-histopathology studies of sporadic human cerebral small vessel disease: A systematic review. Neuropathol Appl Neurobiol 2021; 47:910-930. [PMID: 34037264 DOI: 10.1111/nan.12737] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/29/2021] [Accepted: 05/02/2021] [Indexed: 11/30/2022]
Abstract
AIMS Sporadic human cerebral small vessel disease (SVD) commonly causes stroke and dementia but its pathogenesis is poorly understood. There are recognised neuroimaging and histopathological features. However, relatively few studies have examined the relationship between the radiological and pathological correlates of SVD; better correlation would promote greater insight into the underlying biological changes. METHODS We performed a systematic review to collate and appraise the information derived from studies that correlated histological with neuroimaging-defined SVD lesions. We searched for studies describing post-mortem imaging and histological tissue examination in adults, extracted data from published studies, categorised the information and compiled this narrative. RESULTS We identified 38 relevant studies, including at least 1146 subjects, 342 of these with SVD: 29 studies focussed on neuroradiological white matter lesions (WML), six on microinfarcts and three on dilated perivascular spaces (PVS) and lacunes. The histopathology terminology was diverse with few robust definitions. Reporting and methodology varied widely between studies, precluding formal meta-analysis. PVS and 'oedema' were frequent findings in WML, being described in at least 94 and 18 radiological WML, respectively, in addition to myelin pallor. Histopathological changes extended beyond the radiological lesion margins in at least 33 radiological WML. At least 43 radiological lesions not seen pathologically and at least 178 histological lesions were not identified on imaging. CONCLUSIONS Histopathological assessment of human SVD is hindered by inconsistent methodological approaches and unstandardised definitions. The data from this systematic review will help to develop standardised definitions to promote consistency in human SVD research.
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Affiliation(s)
| | - Colin Smith
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Joanna M Wardlaw
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute at The University of Edinburgh, Edinburgh, UK.,Row Fogo Centre for Research into Ageing and the Brain, Edinburgh, UK
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30
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Lazari A, Lipp I. Can MRI measure myelin? Systematic review, qualitative assessment, and meta-analysis of studies validating microstructural imaging with myelin histology. Neuroimage 2021; 230:117744. [PMID: 33524576 PMCID: PMC8063174 DOI: 10.1016/j.neuroimage.2021.117744] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/05/2021] [Accepted: 01/09/2021] [Indexed: 12/16/2022] Open
Abstract
Recent years have seen an increased understanding of the importance of myelination in healthy brain function and neuropsychiatric diseases. Non-invasive microstructural magnetic resonance imaging (MRI) holds the potential to expand and translate these insights to basic and clinical human research, but the sensitivity and specificity of different MR markers to myelination is a subject of debate. To consolidate current knowledge on the topic, we perform a systematic review and meta-analysis of studies that validate microstructural imaging by combining it with myelin histology. We find meta-analytic evidence for correlations between various myelin histology metrics and markers from different MRI modalities, including fractional anisotropy, radial diffusivity, macromolecular pool, magnetization transfer ratio, susceptibility and longitudinal relaxation rate, but not mean diffusivity. Meta-analytic correlation effect sizes range widely, between R2 = 0.26 and R2 = 0.82. However, formal comparisons between MRI-based myelin markers are limited by methodological variability, inconsistent reporting and potential for publication bias, thus preventing the establishment of a single most sensitive strategy to measure myelin with MRI. To facilitate further progress, we provide a detailed characterisation of the evaluated studies as an online resource. We also share a set of 12 recommendations for future studies validating putative MR-based myelin markers and deploying them in vivo in humans.
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Affiliation(s)
- Alberto Lazari
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Ilona Lipp
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
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31
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Lee H, Lee MJ, Kim EJ, Huh GY, Lee JH, Cho H. Iron accumulation in the oculomotor nerve of the progressive supranuclear palsy brain. Sci Rep 2021; 11:2950. [PMID: 33536537 PMCID: PMC7859181 DOI: 10.1038/s41598-021-82469-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
Abnormal iron accumulation around the substantia nigra (SN) is a diagnostic indicator of Parkinsonism. This study aimed to identify iron-related microarchitectural changes around the SN of brains with progressive supranuclear palsy (PSP) via postmortem validations and in vivo magnetic resonance imaging (MRI). 7 T high-resolution MRI was applied to two postmortem brain tissues, from one normal brain and one PSP brain. Histopathological examinations were performed to demonstrate the molecular origin of the high-resolution postmortem MRI findings, by using ferric iron staining, myelin staining, and two-dimensional laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging. In vivo iron-related MRI was performed on five healthy controls, five patients with Parkinson’s disease (PD), and five patients with PSP. In the postmortem examination, excessive iron deposition along the myelinated fiber at the anterior SN and third cranial nerve (oculomotor nerve) fascicles of the PSP brain was verified by LA-ICP-MS. This region corresponded to those with high R2* values and positive susceptibility from quantitative susceptibility mapping (QSM), but was less sensitive in Perls’ Prussian blue staining. In in vivo susceptibility-weighted imaging, hypointense pixels were observed in the region between the SN and red nucleus (RN) in patients with PSP, but not in healthy controls and patients with PD. R2* and QSM values of such region were significantly higher in patients with PSP compared to those in healthy controls and patients with PD as well (vs. healthy control: p = 0.008; vs. PD: p = 0.008). Thus, excessive iron accumulation along the myelinated fibers at the anterior SN and oculomotor nerve fascicles may be a pathological characteristic and crucial MR biomarker in a brain with PSP.
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Affiliation(s)
- Hansol Lee
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, 50, UNIST-Gil, Eonyang-eup, Ulju-gun, Ulsan, South Korea
| | - Myung Jun Lee
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea
| | - Eun-Joo Kim
- Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, South Korea
| | - Gi Yeong Huh
- Department of Forensic Medicine, Pusan National University School of Medicine, Yangsan, South Korea
| | - Jae-Hyeok Lee
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, 20, Geumo-ro, Mulgeum-eup, Yangsan-si, Gyeongsangnam-do, South Korea.
| | - HyungJoon Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, 50, UNIST-Gil, Eonyang-eup, Ulju-gun, Ulsan, South Korea.
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Wang C, Foxley S, Ansorge O, Bangerter-Christensen S, Chiew M, Leonte A, Menke RA, Mollink J, Pallebage-Gamarallage M, Turner MR, Miller KL, Tendler BC. Methods for quantitative susceptibility and R2* mapping in whole post-mortem brains at 7T applied to amyotrophic lateral sclerosis. Neuroimage 2020; 222:117216. [PMID: 32745677 PMCID: PMC7775972 DOI: 10.1016/j.neuroimage.2020.117216] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/03/2020] [Accepted: 07/27/2020] [Indexed: 12/12/2022] Open
Abstract
Susceptibility weighted magnetic resonance imaging (MRI) is sensitive to the local concentration of iron and myelin. Here, we describe a robust image processing pipeline for quantitative susceptibility mapping (QSM) and R2* mapping of fixed post-mortem, whole-brain data. Using this pipeline, we compare the resulting quantitative maps in brains from patients with amyotrophic lateral sclerosis (ALS) and controls, with validation against iron and myelin histology. Twelve post-mortem brains were scanned with a multi-echo gradient echo sequence at 7T, from which susceptibility and R2* maps were generated. Semi-quantitative histological analysis for ferritin (the principal iron storage protein) and myelin proteolipid protein was performed in the primary motor, anterior cingulate and visual cortices. Magnetic susceptibility and R2* values in primary motor cortex were higher in ALS compared to control brains. Magnetic susceptibility and R2* showed positive correlations with both myelin and ferritin estimates from histology. Four out of nine ALS brains exhibited clearly visible hyperintense susceptibility and R2* values in the primary motor cortex. Our results demonstrate the potential for MRI-histology studies in whole, fixed post-mortem brains to investigate the biophysical source of susceptibility weighted MRI signals in neurodegenerative diseases like ALS.
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Affiliation(s)
- Chaoyue Wang
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom.
| | - Sean Foxley
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom; Department of Radiology, University of Chicago, United States
| | - Olaf Ansorge
- Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom
| | - Sarah Bangerter-Christensen
- Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom; Brigham Young University, Provo, United States
| | - Mark Chiew
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom
| | - Anna Leonte
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom; University of Groningen,the Netherlands
| | - Ricarda Al Menke
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom
| | - Jeroen Mollink
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom; Department of Anatomy, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, the Netherlands
| | | | - Martin R Turner
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom; Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom
| | - Karla L Miller
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom
| | - Benjamin C Tendler
- Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, FMRIB, University of Oxford, United Kingdom
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Kim S, Sakaie K, Blümcke I, Jones S, Lowe MJ. Whole-brain, ultra-high spatial resolution ex vivo MRI with off-the-shelf components. Magn Reson Imaging 2020; 76:39-48. [PMID: 33197550 DOI: 10.1016/j.mri.2020.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/09/2020] [Accepted: 11/09/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Ultra-high spatial resolution imaging of whole, ex vivo brains provides new opportunities to understand neurological disease. Recent work has demonstrated that 100 μm isotropic resolution can reveal anatomical details that are otherwise difficult to appreciate, but relied on fabrication facilities, fabrication expertise and programming expertise that is not available at clinical imaging sites that lack a dedicated research staff and resources. The purpose of this work is to describe a whole-brain, ultra-high spatial resolution imaging procedure for ex vivo specimens using equipment that can be purchased, assembled and implemented by most clinical sites. We provide enough detail so that other groups can readily reproduce the approach. METHODS A container and hardware for holding the brain fixed for long scan times was developed, along with a procedure for removing bubbles, which can cause artifact. Imaging was performed on a standard knee coil on a whole-body 7 T MRI at 170 μm isotropic spatial resolution. Five specimens were examined in Fomblin or formalin to evaluate consistency of image quality. RESULTS High quality images were acquired on all specimens. Anatomical features that are not readily observed at standard resolution, such as subthalamic nuclei, are readily observed. Disease-related features such as microscopic infarcts are also readily observed. CONCLUSIONS Ultra-high spatial resolution, whole-brain images can be readily achieved without specialized hardware and software development. The approach is expected to be valuable as a complement to histology and to discover relationships among pathology located at different places throughout the brain.
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Affiliation(s)
- Sanghoon Kim
- Imaging Institute, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-15, Cleveland, OH 44195, USA
| | - Ken Sakaie
- Imaging Institute, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-15, Cleveland, OH 44195, USA
| | - Ingmar Blümcke
- Institute of Neuropathology, Universitätsklinikum Erlangen, Schwabachanlage 6 (Kopfkliniken), 91054 Erlangen, Germany
| | - Stephen Jones
- Imaging Institute, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-15, Cleveland, OH 44195, USA
| | - Mark J Lowe
- Imaging Institute, The Cleveland Clinic, 9500 Euclid Ave, Mail code U-15, Cleveland, OH 44195, USA.
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Tendler BC, Foxley S, Hernandez-Fernandez M, Cottaar M, Scott C, Ansorge O, Miller KL, Jbabdi S. Use of multi-flip angle measurements to account for transmit inhomogeneity and non-Gaussian diffusion in DW-SSFP. Neuroimage 2020; 220:117113. [PMID: 32621975 PMCID: PMC7573656 DOI: 10.1016/j.neuroimage.2020.117113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 11/06/2022] Open
Abstract
Diffusion-weighted steady-state free precession (DW-SSFP) is an SNR-efficient diffusion imaging method. The improved SNR and resolution available at ultra-high field has motivated its use at 7T. However, these data tend to have severe B1 inhomogeneity, leading not only to spatially varying SNR, but also to spatially varying diffusivity estimates, confounding comparisons both between and within datasets. This study proposes the acquisition of DW-SSFP data at two-flip angles in combination with explicit modelling of non-Gaussian diffusion to address B1 inhomogeneity at 7T. Data were acquired from five fixed whole human post-mortem brains with a pair of flip angles that jointly optimize the diffusion contrast-to-noise (CNR) across the brain. We compared one- and two-flip angle DW-SSFP data using a tensor model that incorporates the full DW-SSFP Buxton signal, in addition to tractography performed over the cingulum bundle and pre-frontal cortex using a ball & sticks model. The two-flip angle DW-SSFP data produced angular uncertainty and tractography estimates close to the CNR optimal regions in the single-flip angle datasets. The two-flip angle tensor estimates were subsequently fitted using a modified DW-SSFP signal model that incorporates a gamma distribution of diffusivities. This allowed us to generate tensor maps at a single effective b-value yielding more consistent SNR across tissue, in addition to eliminating the B1 dependence on diffusion coefficients and orientation maps. Our proposed approach will allow the use of DW-SSFP at 7T to derive diffusivity estimates that have greater interpretability, both within a single dataset and between experiments.
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Affiliation(s)
- Benjamin C Tendler
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
| | - Sean Foxley
- Department of Radiology, University of Chicago, Chicago, IL, USA
| | | | - Michiel Cottaar
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Connor Scott
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Olaf Ansorge
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Karla L Miller
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Saad Jbabdi
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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35
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Alkemade A, Pine K, Kirilina E, Keuken MC, Mulder MJ, Balesar R, Groot JM, Bleys RLAW, Trampel R, Weiskopf N, Herrler A, Möller HE, Bazin PL, Forstmann BU. 7 Tesla MRI Followed by Histological 3D Reconstructions in Whole-Brain Specimens. Front Neuroanat 2020; 14:536838. [PMID: 33117133 PMCID: PMC7574789 DOI: 10.3389/fnana.2020.536838] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 09/14/2020] [Indexed: 11/24/2022] Open
Abstract
Post mortem magnetic resonance imaging (MRI) studies on the human brain are of great interest for the validation of in vivo MRI. It facilitates a link between functional and anatomical information available from MRI in vivo and neuroanatomical knowledge available from histology/immunocytochemistry. However, linking in vivo and post mortem MRI to microscopy techniques poses substantial challenges. Fixation artifacts and tissue deformation of extracted brains, as well as co registration of 2D histology to 3D MRI volumes complicate direct comparison between modalities. Moreover, post mortem brain tissue does not have the same physical properties as in vivo tissue, and therefore MRI approaches need to be adjusted accordingly. Here, we present a pipeline in which whole-brain human post mortem in situ MRI is combined with subsequent tissue processing of the whole human brain, providing a 3-dimensional reconstruction via blockface imaging. To this end, we adapted tissue processing procedures to allow both post mortem MRI and subsequent histological and immunocytochemical processing. For MRI, tissue was packed in a susceptibility matched solution, tailored to fit the dimensions of the MRI coil. Additionally, MRI sequence parameters were adjusted to accommodate T1 and T2∗ shortening, and scan time was extended, thereby benefiting the signal-to-noise-ratio that can be achieved using extensive averaging without motion artifacts. After MRI, the brain was extracted from the skull and subsequently cut while performing optimized blockface imaging, thereby allowing three-dimensional reconstructions. Tissues were processed for Nissl and silver staining, and co-registered with the blockface images. The combination of these techniques allows direct comparisons across modalities.
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Affiliation(s)
- Anneke Alkemade
- Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands
| | - Kerrin Pine
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Evgeniya Kirilina
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Neurocomputation and Neuroimaging Unit, Department of Psychology and Educational Science, Free University Berlin, Berlin, Germany
| | - Max C Keuken
- Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands
| | - Martijn J Mulder
- Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands.,Department of Experimental Psychology, Utrecht University, Utrecht, Netherlands
| | - Rawien Balesar
- Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands.,The Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Josephine M Groot
- Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands
| | - Ronald L A W Bleys
- Department of Anatomy, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Robert Trampel
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Andreas Herrler
- Department of Anatomy and Embryology, Maastricht University, Maastricht, Netherlands
| | - Harald E Möller
- NMR Methods & Development Group, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Pierre-Louis Bazin
- Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands.,Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Birte U Forstmann
- Integrative Model-Based Neuroscience Research Unit, University of Amsterdam, Amsterdam, Netherlands
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Stringer MS, Lee H, Huuskonen MT, MacIntosh BJ, Brown R, Montagne A, Atwi S, Ramirez J, Jansen MA, Marshall I, Black SE, Zlokovic BV, Benveniste H, Wardlaw JM. A Review of Translational Magnetic Resonance Imaging in Human and Rodent Experimental Models of Small Vessel Disease. Transl Stroke Res 2020; 12:15-30. [PMID: 32936435 PMCID: PMC7803876 DOI: 10.1007/s12975-020-00843-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/16/2020] [Accepted: 08/19/2020] [Indexed: 12/29/2022]
Abstract
Cerebral small vessel disease (SVD) is a major health burden, yet the pathophysiology remains poorly understood with no effective treatment. Since much of SVD develops silently and insidiously, non-invasive neuroimaging such as MRI is fundamental to detecting and understanding SVD in humans. Several relevant SVD rodent models are established for which MRI can monitor in vivo changes over time prior to histological examination. Here, we critically review the MRI methods pertaining to salient rodent models and evaluate synergies with human SVD MRI methods. We found few relevant publications, but argue there is considerable scope for greater use of MRI in rodent models, and opportunities for harmonisation of the rodent-human methods to increase the translational potential of models to understand SVD in humans. We summarise current MR techniques used in SVD research, provide recommendations and examples and highlight practicalities for use of MRI SVD imaging protocols in pre-selected, relevant rodent models.
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Affiliation(s)
- Michael S Stringer
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Mikko T Huuskonen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Bradley J MacIntosh
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Rosalind Brown
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Axel Montagne
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Sarah Atwi
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Joel Ramirez
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Maurits A Jansen
- Edinburgh Preclinical Imaging, Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
| | - Ian Marshall
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Sandra E Black
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada.,Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, ON, Canada.,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - Berislav V Zlokovic
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Joanna M Wardlaw
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK. .,UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK.
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Lohr D, Terekhov M, Veit F, Schreiber LM. Longitudinal assessment of tissue properties and cardiac diffusion metrics of the ex vivo porcine heart at 7 T: Impact of continuous tissue fixation using formalin. NMR IN BIOMEDICINE 2020; 33:e4298. [PMID: 32207190 DOI: 10.1002/nbm.4298] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/18/2020] [Accepted: 03/05/2020] [Indexed: 05/12/2023]
Abstract
In this study we aimed to assess the effects of continuous formalin fixation on diffusion and relaxation metrics of the ex vivo porcine heart at 7 T. Magnetic resonance imaging was performed on eight piglet hearts using a 7 T whole body system. Hearts were measured fresh within 3 hours of cardiac arrest followed by immersion in 10% neutral buffered formalin. T2* and T2 were assessed using a gradient multi-echo and multi-echo spin echo sequence, respectively. A spin echo and a custom stimulated echo sequence were employed to assess diffusion time-dependent changes in metrics of cardiac diffusion tensor imaging. SNR was determined for b = 0 images. Scans were performed for 5 mm thick apical, midcavity and basal slices (in-plane resolution: 1 mm) and repeated 7, 15, 50, 100 and 200 days postfixation. Eigenvalues of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) decreased significantly (P < 0.05) following fixation. Relative to fresh hearts, FA values 7 and 200 days postfixation were 90% and 80%, while respective relative ADC values at those fixation stages were 78% and 92%. Statistical helix and sheetlet angle distributions as well as respective mean and median values showed no systematic influence of continuous formalin fixation. Similar to changes in the ADC, values for T2 , T2* and SNR dropped initially postfixation. Respective relative values compared with fresh hearts at day 7 were 64%, 79% and 68%, whereas continuous fixation restored T2 , T2* and SNR leading to relative values of 74%, 100%, and 81% at day 200, respectively. Relaxation parameters and diffusion metrics are significantly altered by continuous formalin fixation. The preservation of microstructure metrics following prolonged fixation is a key finding that may enable future studies of ventricular remodeling in cardiac pathologies.
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Affiliation(s)
- David Lohr
- Cellular and Molecular Imaging, Comprehensive Heart Failure Center (CHFC), University Hospital Wuerzburg, Wuerzburg, Germany
| | - Maxim Terekhov
- Cellular and Molecular Imaging, Comprehensive Heart Failure Center (CHFC), University Hospital Wuerzburg, Wuerzburg, Germany
| | - Franziska Veit
- Tissue Engineering and Regenerative Medicine (TERM), University Hospital Wuerzburg, Wuerzburg, Germany
| | - Laura Maria Schreiber
- Cellular and Molecular Imaging, Comprehensive Heart Failure Center (CHFC), University Hospital Wuerzburg, Wuerzburg, Germany
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38
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Shared proteomic effects of cerebral atherosclerosis and Alzheimer's disease on the human brain. Nat Neurosci 2020; 23:696-700. [PMID: 32424284 PMCID: PMC7269838 DOI: 10.1038/s41593-020-0635-5] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/01/2020] [Indexed: 01/07/2023]
Abstract
Cerebral atherosclerosis contributes to dementia via unclear processes. We performed proteomic sequencing of dorsolateral prefrontal cortex in 438 older individuals and found associations between cerebral atherosclerosis and reduced synaptic signaling and RNA splicing and increased oligodendrocyte development and myelination. Consistently, single-cell RNA sequencing showed cerebral atherosclerosis associated with higher oligodendrocyte abundance. A subset of proteins and modules associated with cerebral atherosclerosis was also associated with Alzheimer’s disease, suggesting shared mechanisms.
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Yates NJ, Feindel KW, Mehnert A, Beare R, Quick S, Blache D, Pillow JJ, Hunt RW. Ex Vivo MRI Analytical Methods and Brain Pathology in Preterm Lambs Treated with Postnatal Dexamethasone †. Brain Sci 2020; 10:brainsci10040211. [PMID: 32260193 PMCID: PMC7226431 DOI: 10.3390/brainsci10040211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/26/2020] [Accepted: 04/01/2020] [Indexed: 01/22/2023] Open
Abstract
Postnatal glucocorticoids such as dexamethasone are effective in promoting lung development in preterm infants, but are prescribed cautiously due to concerns of neurological harm. We developed an analysis pipeline for post-mortem magnetic resonance imaging (MRI) to assess brain development and hence the neurological safety profile of postnatal dexamethasone in preterm lambs. Lambs were delivered via caesarean section at 129 days’ (d) gestation (full term ≈ 150 d) with saline-vehicle control (Saline, n = 9), low-dose tapered dexamethasone (cumulative dose = 0.75 mg/kg, n = 8), or high-dose tapered dexamethasone (cumulative dose = 2.67 mg/kg, n = 8), for seven days. Naïve fetal lambs (136 d gestation) were used as end-point maturation controls. The left-brain hemispheres were immersion-fixed in 10 % formalin (24 h), followed by paraformaldehyde (>6 months). Image sequences were empirically optimized for T1- and T2-weighted MRI and analysed using accessible methods. Spontaneous lesions detected in the white matter of the frontal cortex, temporo-parietal cortex, occipital lobe, and deep to the parahippocampal gyrus were confirmed with histology. Neither postnatal dexamethasone treatment nor gestation showed any associations with lesion incidence, frontal cortex (total, white, or grey matter) or hippocampal volume (all p > 0.05). Postnatal dexamethasone did not appear to adversely affect neurodevelopment. Our post-mortem MRI analysis pipeline is suitable for other animal models of brain development.
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Affiliation(s)
- Nathanael J. Yates
- School of Human Sciences, University of Western Australia, Perth 6009, Australia;
- Queensland Brain Institute, University of Queensland, Brisbane 4072, Australia
- Correspondence: ; Tel.: +61-7-344-66361
| | - Kirk W. Feindel
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia; (K.W.F.); (A.M.); (S.Q.)
- School of Biomedical Sciences, University of Western Australia, Perth 6009, Australia
| | - Andrew Mehnert
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia; (K.W.F.); (A.M.); (S.Q.)
| | - Richard Beare
- Developmental Imaging, Murdoch Children’s Research Institute, Melbourne 3052, Australia;
- Department of Medicine, Monash University, Melbourne 3800, Australia
| | - Sophia Quick
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia; (K.W.F.); (A.M.); (S.Q.)
| | - Dominique Blache
- School of Agriculture and Environment, University of Western Australia, Perth 6009, Australia;
| | - J. Jane Pillow
- School of Human Sciences, University of Western Australia, Perth 6009, Australia;
| | - Rod W. Hunt
- Murdoch Children’s Research Institute, Melbourne 3052, Australia;
- Department of Paediatrics, University of Melbourne, Melbourne 3052, Australia
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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] [Grants] [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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El Kininy W, Roddy D, Davy S, Roman E, O'Keane V, O'Hanlon E, Barry D, Stassen LFA. Magnetic resonance diffusion weighted imaging using constrained spherical deconvolution-based tractography of the extracranial course of the facial nerve. Oral Surg Oral Med Oral Pathol Oral Radiol 2020; 130:e44-e56. [PMID: 32033932 DOI: 10.1016/j.oooo.2019.12.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 12/07/2019] [Accepted: 12/20/2019] [Indexed: 12/18/2022]
Abstract
OBJECTIVE To evaluate the accuracy of magnetic resonance diffusion weighted imaging (DWI) featuring constrained spherical deconvolution-based tractography in tracking the extracranial course of the facial nerve to provide a reliable facial nerve map to facilitate well-tolerated and effective tumor resection. STUDY DESIGN Magnetic resonance DWI was conducted on 2 parotid-healthy cadaveric patients with various protocols to identify the best representation of the extracranial facial nerve tract. This was subsequently correlated to dissection of the facial nerves to ascertain anatomic validation. These protocols were applied to 2 live, parotid-healthy patients to assess feasibility of in vivo facial nerve tract identification. RESULTS Correlations between imaged tracts and the anatomic course of the extracranial facial nerve were identified to an accuracy of 1 mm. The main trunk and bifurcation tracts were identified on imaging. Fractional anisometry values in cadaveric and live patients were within the range expected for the facial nerve within the parotid gland. CONCLUSIONS Our results indicated the potential for accurate 3-dimensional visualization of the extracranial course of the facial nerve, which could have diagnostic implications in differentiating benign from malignant tumors and, crucially, neural involvement. Preoperative planning applications of DWI could help in planning surgical approaches and providing focused counseling.
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Affiliation(s)
- Walid El Kininy
- Trinity College Dublin - M.D. post graduate doctorate and Specialist Registrar, Oral & Maxillofacial Surgery, Kent Surrey Sussex Deanery, UK.
| | - Darren Roddy
- Neuroscience Institute, Trinity College Dublin, Dublin, Ireland
| | - Shane Davy
- Department of Anatomy, Trinity College Dublin
| | | | | | - Erik O'Hanlon
- Senior postdoctoral research fellow, Neuroscience, Trinity College Dublin
| | - Denis Barry
- Assistant professor and M.D. supervisor, Department of Anatomy, Trinity College Dublin
| | - Leo F A Stassen
- Professor and chair of Oral/Maxillofacial Surgery and M.D. supervisor, Trinity College Dublin
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Gaiteri C, Dawe R, Mostafavi S, Blizinsky KD, Tasaki S, Komashko V, Yu L, Wang Y, Schneider JA, Arfanakis K, De Jager PL, Bennett DA. Gene expression and DNA methylation are extensively coordinated with MRI-based brain microstructural characteristics. Brain Imaging Behav 2020; 13:963-972. [PMID: 29934819 PMCID: PMC6309607 DOI: 10.1007/s11682-018-9910-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cognitive function relies on both molecular levels and cellular structures. However, systematic relationships between these two components of cognitive function, and their joint contribution to disease, are largely unknown. We utilize postmortem neuroimaging in tandem with gene expression and DNA methylation, from 222 deeply-phenotyped persons in a longitudinal aging cohort. Expression of hundreds of genes and methylation at thousands of loci are related to the microstructure of extensive regions of this same set of brains, as assessed by MRI. The genes linked to brain microstructure perform functions related to cell motility, transcriptional regulation and nuclear processes, and are selectively associated with Alzheimer’s phenotypes. Similar methodology can be applied to other diseases to identify their joint molecular and structural basis, or to infer molecular levels in the brain on the basis of neuroimaging for precision medicine applications.
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Affiliation(s)
- Chris Gaiteri
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.
| | - Robert Dawe
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.,Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Sara Mostafavi
- Department of Statistics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Katherine D Blizinsky
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.,National Institutes of Health, National Human Genome Research Institute, Bethesda, MD, USA
| | - Shinya Tasaki
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Vitalina Komashko
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Yanling Wang
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Konstantinos Arfanakis
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.,Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL, USA.,Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Philip L De Jager
- Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
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Dawe RJ, Yu L, Arfanakis K, Schneider JA, Bennett DA, Boyle PA. Late-life cognitive decline is associated with hippocampal volume, above and beyond its associations with traditional neuropathologic indices. Alzheimers Dement 2020; 16:209-218. [PMID: 31914231 PMCID: PMC6953608 DOI: 10.1002/alz.12009] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 07/12/2019] [Accepted: 11/01/2019] [Indexed: 01/18/2023]
Abstract
INTRODUCTION Reduced hippocampal volume is associated with late-life cognitive decline, but prior studies have not determined whether this association persists after accounting for Alzheimer's disease (AD) and other neuropathologies. METHODS Participants were 531 deceased older adults from community-based cohort studies of aging who had undergone annual cognitive evaluations. At death, brain tissue underwent neuropathologic examination and magnetic resonance imaging (MRI). Linear mixed models examined whether hippocampal volume measured via MRI accounted for variation in decline rate of global cognition and five cognitive domains, above and beyond neuropathologic indices. RESULTS Demographics and indices of AD, cerebrovascular disease, Lewy body disease, hippocampal sclerosis, TDP-43, and atherosclerosis accounted for 42.6% of the variation in global cognitive decline. Hippocampal volume accounted for an additional 5.4% of this variation and made similar contributions in four of the five cognitive domains. DISCUSSION Hippocampal volume is associated with late-life cognitive decline, above and beyond contributions from common neuropathologic indices.
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Affiliation(s)
- Robert J. Dawe
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Lei Yu
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Konstantinos Arfanakis
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL, USA
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Julie A. Schneider
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
- Department of Pathology, Rush University Medical Center, Chicago, IL, USA
| | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Patricia A. Boyle
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Behavioral Sciences, Rush University Medical Center, Chicago, IL, USA
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Vučković I, Nayfeh T, Mishra PK, Periyanan S, Sussman CR, Kline TL, Macura S. Influence of water based embedding media composition on the relaxation properties of fixed tissue. Magn Reson Imaging 2019; 67:7-17. [PMID: 31821849 DOI: 10.1016/j.mri.2019.11.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/30/2019] [Accepted: 11/21/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND In MRI of formalin-fixed tissue one of the problems is the dependence of tissue relaxation properties on formalin composition and composition of embedding medium (EM) used for scanning. In this study, we investigated molecular mechanisms by which the EM composition affects T2 relaxation directly and T1 relaxation indirectly. OBJECTIVE To identify principal components of formaldehyde based EM and the mechanism by which they affect relaxation properties of fixed tissue. METHODS We recorded high resolution 1H NMR spectra of common formalin fixatives at temperatures in the range of 5 °C to 45 °C. We also measured T1 and T2 relaxation times of various organs of formalin fixed (FF) zebrafish at 7 T at 21 °C and 31 °C in several EM with and without fixative or gadolinium contrast agents. RESULTS We showed that the major source of T2 variability is chemical exchange between protons from EM hydroxyls and water, mediated by the presence of phosphate ions. The exchange rate increases with temperature, formaldehyde concentration in EM and phosphate concentration in EM. Depending on which side of the coalescence the system resides, the temperature increase can lead to either shortening or prolongation of T2, or to no noticeable change at all when very close to the coalescence. Chemical exchange can be minimized by washing out from EM the fixative, the phosphate or both. CONCLUSION The dependence of T2 in fixed tissue on the fixative origin and composition described in prior literature could be attributed to the phosphate buffer accelerated chemical exchange among the fixative hydroxyls and the tissue water. More consistent results in the relaxation measurements could be obtained by stricter control of the fixative composition or by scanning fixed tissue in PBS without fixative.
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Affiliation(s)
- Ivan Vučković
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Tarek Nayfeh
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Prasanna K Mishra
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Caroline R Sussman
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
| | - Timothy L Kline
- Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Slobodan Macura
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA.
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Wang N, Zhuang J, Wie H, Dibb R, Qi Y, Liu C. Probing demyelination and remyelination of the cuprizone mouse model using multimodality MRI. J Magn Reson Imaging 2019; 50:1852-1865. [PMID: 31012202 PMCID: PMC6810724 DOI: 10.1002/jmri.26758] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 04/07/2019] [Accepted: 04/08/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Various studies by MRI exhibit that the corpus callosum (CC) is the most vulnerable to cuprizone administration, detecting the demyelination and remyelination process using different MRI parameters are, however, lacking. PURPOSE To investigate the sensitivity of multiparametric MRI both in vivo and ex vivo for demyelination and remyelination. STUDY TYPE Prospective. ANIMAL MODEL A cuprizone mice model with an age-matched control group (n = 5), 4-week cuprizone exposure group followed by 9-week on a normal diet (n = 6), and a 13-week cuprizone exposure group (n = 6). FIELD STRENGTH/SEQUENCE 3D gradient recalled echo, T2 -weighted, and diffusion tensor imaging (DTI) at 7.0T and 9.4T. ASSESSMENT Quantification of DTI metrics, quantitative susceptibility mapping (QSM), and T2 -weighted imaging intensity in major white matter bundles. STATISTICAL TESTS Nonparametric permutation tests were used with a cluster-forming threshold as 3.09 (equivalent to P = 0.001), and the significant level as P = 0.05 with family-wise correction. RESULTS In vivo susceptibility values increased from -11.7 to -0.7 ppb (P < 0.001) in CC and from -13.7 to -5.1 ppb (P < 0.001) in the anterior commissure (AC) after the 13-week cuprizone exposure. Ex vivo susceptibility values increased from -25.4 to 7.4 ppb (P < 0.001) in CC and from -41.6 to -15.8 ppb (P < 0.001) in AC. Susceptibility values showed high variations to demyelination for in vivo studies (94.0% in CC, 62.8% in AC). Susceptibility values exhibited higher variations than radial diffusivity for ex vivo studies (129.1% vs. 28.3% in CC, 62.0% vs. 25.0% in AC). In addition to the differential susceptibility variations in different white matter tracts, intraregional demyelination variation was also present not only in CC but also in the AC area by voxel-based analysis. DATA CONCLUSION QSM is sensitive to the demyelination process of cuprizone exposure, which can be a complementary technique to conventional T2 -weighted images and DTI metrics. LEVEL OF EVIDENCE 2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;50:1852-1865.
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Affiliation(s)
- Nian Wang
- Center for In Vivo Microscopy, Duke University, Durham, North Carolina, USA
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
| | - Jie Zhuang
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
| | - Hongjiang Wie
- Brain Imaging and Analysis Center, Duke University, Durham, North Carolina, USA
| | - Russell Dibb
- Center for In Vivo Microscopy, Duke University, Durham, North Carolina, USA
| | - Yi Qi
- Center for In Vivo Microscopy, Duke University, Durham, North Carolina, USA
| | - Chunlei Liu
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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Yu L, Boyle PA, Dawe RJ, Bennett DA, Arfanakis K, Schneider JA. Contribution of TDP and hippocampal sclerosis to hippocampal volume loss in older-old persons. Neurology 2019; 94:e142-e152. [PMID: 31757868 DOI: 10.1212/wnl.0000000000008679] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/10/2019] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE To investigate the contribution of Alzheimer disease (AD) vs non-AD neuropathologies to hippocampal atrophy. METHODS The Religious Orders Study and Rush Memory and Aging Project are clinicopathologic cohort studies of aging. The current study included 547 participants who had undergone brain autopsy and postmortem hippocampal volume measurement by November 1, 2018. Hippocampal volume was measured with postmortem MRI via a 3D region of interest applied to the hippocampal formation. Neuropathologies were measured via uniform structured evaluations. Linear regression analyses estimated the proportion of variance of hippocampal volume attributable to AD and non-AD neuropathologies. RESULTS The average age at death was 90 years, and the average hippocampal volume was 2.1 mL. AD, transactive response DNA-binding protein 43 (TDP), hippocampal sclerosis (HS), and atherosclerosis were associated with hippocampal volume. After demographics and total hemisphere volume were controlled for, 7.0% of the variance (95% bootstrapped confidence interval [CI] 4.3%-10.5%) of hippocampal volume was attributable to AD pathology. TDP/HS explained an additional 4.5% (95% CI 2.2%-7.6%). Among individuals with Alzheimer dementia (n = 232), 3.1% (95% CI 0.6%-7.7%) of the variance was attributable to AD pathology, and TDP/HS explained an additional 6.1% (95% CI 2.2%-11.6%). Among those without Alzheimer dementia (n = 307), 3.2% (95% CI 0.9%-7.3%) of the variance was attributable to AD pathology, and TDP/HS explained an additional 1.1%, which did not reach statistical significance. Lewy bodies and vascular diseases had modest contribution to the variance of hippocampal volume. CONCLUSIONS Both AD and TDP/HS contribute to hippocampal volume loss in older-old persons, with TDP/HS more strongly associated with hippocampal volume than AD in Alzheimer dementia.
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Affiliation(s)
- Lei Yu
- From the Rush Alzheimer's Disease Center (L.Y., P.A.B., R.J.D., D.A.B., K.A., J.A.S.), Department of Neurological Sciences (L.Y., D.A.B., J.A.S.), Department of Behavioral Sciences (P.A.B.), Department of Diagnostic Radiology and Nuclear Medicine (R.J.D., K.A.), and Department of Pathology (J.A.S.), Rush University Medical Center; and Department of Biomedical Engineering (K.A.), Illinois Institute of Technology, Chicago.
| | - Patricia A Boyle
- From the Rush Alzheimer's Disease Center (L.Y., P.A.B., R.J.D., D.A.B., K.A., J.A.S.), Department of Neurological Sciences (L.Y., D.A.B., J.A.S.), Department of Behavioral Sciences (P.A.B.), Department of Diagnostic Radiology and Nuclear Medicine (R.J.D., K.A.), and Department of Pathology (J.A.S.), Rush University Medical Center; and Department of Biomedical Engineering (K.A.), Illinois Institute of Technology, Chicago
| | - Robert J Dawe
- From the Rush Alzheimer's Disease Center (L.Y., P.A.B., R.J.D., D.A.B., K.A., J.A.S.), Department of Neurological Sciences (L.Y., D.A.B., J.A.S.), Department of Behavioral Sciences (P.A.B.), Department of Diagnostic Radiology and Nuclear Medicine (R.J.D., K.A.), and Department of Pathology (J.A.S.), Rush University Medical Center; and Department of Biomedical Engineering (K.A.), Illinois Institute of Technology, Chicago
| | - David A Bennett
- From the Rush Alzheimer's Disease Center (L.Y., P.A.B., R.J.D., D.A.B., K.A., J.A.S.), Department of Neurological Sciences (L.Y., D.A.B., J.A.S.), Department of Behavioral Sciences (P.A.B.), Department of Diagnostic Radiology and Nuclear Medicine (R.J.D., K.A.), and Department of Pathology (J.A.S.), Rush University Medical Center; and Department of Biomedical Engineering (K.A.), Illinois Institute of Technology, Chicago
| | - Konstantinos Arfanakis
- From the Rush Alzheimer's Disease Center (L.Y., P.A.B., R.J.D., D.A.B., K.A., J.A.S.), Department of Neurological Sciences (L.Y., D.A.B., J.A.S.), Department of Behavioral Sciences (P.A.B.), Department of Diagnostic Radiology and Nuclear Medicine (R.J.D., K.A.), and Department of Pathology (J.A.S.), Rush University Medical Center; and Department of Biomedical Engineering (K.A.), Illinois Institute of Technology, Chicago
| | - Julie A Schneider
- From the Rush Alzheimer's Disease Center (L.Y., P.A.B., R.J.D., D.A.B., K.A., J.A.S.), Department of Neurological Sciences (L.Y., D.A.B., J.A.S.), Department of Behavioral Sciences (P.A.B.), Department of Diagnostic Radiology and Nuclear Medicine (R.J.D., K.A.), and Department of Pathology (J.A.S.), Rush University Medical Center; and Department of Biomedical Engineering (K.A.), Illinois Institute of Technology, Chicago
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McFadden WC, Walsh H, Richter F, Soudant C, Bryce CH, Hof PR, Fowkes M, Crary JF, McKenzie AT. Perfusion fixation in brain banking: a systematic review. Acta Neuropathol Commun 2019; 7:146. [PMID: 31488214 PMCID: PMC6728946 DOI: 10.1186/s40478-019-0799-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 08/26/2019] [Indexed: 01/12/2023] Open
Abstract
Background Perfusing fixatives through the cerebrovascular system is the gold standard approach in animals to prepare brain tissue for spatial biomolecular profiling, circuit tracing, and ultrastructural studies such as connectomics. Translating these discoveries to humans requires examination of postmortem autopsy brain tissue. Yet banked brain tissue is routinely prepared using immersion fixation, which is a significant barrier to optimal preservation of tissue architecture. The challenges involved in adopting perfusion fixation in brain banks and the extent to which it improves histology quality are not well defined. Methodology We searched four databases to identify studies that have performed perfusion fixation in human brain tissue and screened the references of the eligible studies to identify further studies. From the included studies, we extracted data about the methods that they used, as well as any data comparing perfusion fixation to immersion fixation. The protocol was preregistered at the Open Science Framework: https://osf.io/cv3ys/. Results We screened 4489 abstracts, 214 full-text publications, and identified 35 studies that met our inclusion criteria, which collectively reported on the perfusion fixation of 558 human brains. We identified a wide variety of approaches to perfusion fixation, including perfusion fixation of the brain in situ and ex situ, perfusion fixation through different sets of blood vessels, and perfusion fixation with different washout solutions, fixatives, perfusion pressures, and postfixation tissue processing methods. Through a qualitative synthesis of data comparing the outcomes of perfusion and immersion fixation, we found moderate confidence evidence showing that perfusion fixation results in equal or greater subjective histology quality compared to immersion fixation of relatively large volumes of brain tissue, in an equal or shorter amount of time. Conclusions This manuscript serves as a resource for investigators interested in building upon the methods and results of previous research in designing their own perfusion fixation studies in human brains or other large animal brains. We also suggest several future research directions, such as comparing the in situ and ex situ approaches to perfusion fixation, studying the efficacy of different washout solutions, and elucidating the types of brain donors in which perfusion fixation is likely to result in higher fixation quality than immersion fixation. Electronic supplementary material The online version of this article (10.1186/s40478-019-0799-y) contains supplementary material, which is available to authorized users.
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Thiebaut de Schotten M, Croxson PL, Mars RB. Large-scale comparative neuroimaging: Where are we and what do we need? Cortex 2019; 118:188-202. [PMID: 30661736 PMCID: PMC6699599 DOI: 10.1016/j.cortex.2018.11.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/26/2018] [Accepted: 11/29/2018] [Indexed: 01/26/2023]
Abstract
Neuroimaging has a lot to offer comparative neuroscience. Although invasive "gold standard" techniques have a better spatial resolution, neuroimaging allows fast, whole-brain, repeatable, and multi-modal measurements of structure and function in living animals and post-mortem tissue. In the past years, comparative neuroimaging has increased in popularity. However, we argue that its most significant potential lies in its ability to collect large-scale datasets of many species to investigate principles of variability in brain organisation across whole orders of species-an ambition that is presently unfulfilled but achievable. We briefly review the current state of the field and explore what the current obstacles to such an approach are. We propose some calls to action.
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Affiliation(s)
- Michel Thiebaut de Schotten
- Brain Connectivity and Behaviour Group, Sorbonne Universities, Paris France; Frontlab, Institut du Cerveau et de la Moelle épinière (ICM), UPMC UMRS 1127, Inserm U 1127, CNRS UMR, Paris, France; Groupe d'Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives-UMR 5293, CNRS, CEA University of Bordeaux, Bordeaux, France.
| | - Paula L Croxson
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA.
| | - Rogier B Mars
- Wellcome Centre for Integrative Neuroimaging, Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom; Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands.
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Kim N, Yu L, Dawe R, Petyuk VA, Gaiteri C, De Jager PL, Schneider JA, Arfanakis K, Bennett DA. Microstructural changes in the brain mediate the association of AK4, IGFBP5, HSPB2, and ITPK1 with cognitive decline. Neurobiol Aging 2019; 84:17-25. [PMID: 31479860 DOI: 10.1016/j.neurobiolaging.2019.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/18/2019] [Accepted: 07/19/2019] [Indexed: 12/13/2022]
Abstract
The associations of 4 proteins-AK4, ITPK1, HSPB2, and IGFBP5-with cognitive function in older adults were largely unexplained by known brain pathologies. We examined the extent to which individual protein associations with cognitive decline were attributable to microstructural changes in the brain. This study included 521 participants (mean age 90.3, 65.9-108.3) with the postmortem reciprocal of transverse relaxation time (R2) magnetic resonance image. All participants came from one of the 2 ongoing longitudinal cohorts of aging and dementia, the Religious Orders Study and Rush Memory and Aging Project. Higher abundance of AK4, HSPB2, and IGFBP5 was associated with faster cognitive decline and mediated through lower postmortem R2 in the frontal and temporal white matter regions. In contrast, higher abundance of ITPK1 was associated with slower cognitive decline and mediated through higher postmortem R2 in the frontal and temporal white matter regions. The associations of 4 proteins-AK4, ITPK1, IGFBP5, and HSPB2-with cognition in late life were explained via microstructural changes in the brain.
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Affiliation(s)
- Namhee Kim
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA.
| | - Lei Yu
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Robert Dawe
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Vladislav A Petyuk
- Biological Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Chris Gaiteri
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Philip L De Jager
- Center for Translational and Computational Neuroimmunology, Columbia University Medical Center, New York, NY, USA; Cell Circuits Program, Broad Institute, Cambridge, MA, USA
| | - Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA; Department of Pathology, Rush University Medical Center, Chicago, IL, USA
| | - Konstantinos Arfanakis
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Diagnostic Radiology and Nuclear Medicine, Rush University Medical Center, Chicago, IL, USA; Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
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De Barros A, Arribarat G, Combis J, Chaynes P, Péran P. Matching ex vivo MRI With Iron Histology: Pearls and Pitfalls. Front Neuroanat 2019; 13:68. [PMID: 31333421 PMCID: PMC6616088 DOI: 10.3389/fnana.2019.00068] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 06/19/2019] [Indexed: 12/12/2022] Open
Abstract
Iron levels in the brain can be estimated using newly developed specific magnetic resonance imaging (MRI) sequences. This technique has several applications, especially in neurodegenerative disorders like Alzheimer's disease or Parkinson's disease. Coupling ex vivo MRI with histology allows neuroscientists to better understand what they see in the images. Iron is one of the most extensively studied elements, both by MRI and using histological or physical techniques. Researchers were initially only able to make visual comparisons between MRI images and different types of iron staining, but the emergence of specific MRI sequences like R2* or quantitative susceptibility mapping meant that quantification became possible, requiring correlations with physical techniques. Today, with advances in MRI and image post-processing, it is possible to look for MRI/histology correlations by matching the two sorts of images. For the result to be acceptable, the choice of methodology is crucial, as there are hidden pitfalls every step of the way. In order to review the advantages and limitations of ex vivo MRI correlation with iron-based histology, we reviewed all the relevant articles dealing with the topic in humans. We provide separate assessments of qualitative and quantitative studies, and after summarizing the significant results, we emphasize all the pitfalls that may be encountered.
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Affiliation(s)
- Amaury De Barros
- Toulouse NeuroImaging Center, University of Toulouse Paul Sabatier-INSERM, Toulouse, France
- Department of Anatomy, Toulouse Faculty of Medicine, Toulouse, France
| | - Germain Arribarat
- Toulouse NeuroImaging Center, University of Toulouse Paul Sabatier-INSERM, Toulouse, France
| | - Jeanne Combis
- Toulouse NeuroImaging Center, University of Toulouse Paul Sabatier-INSERM, Toulouse, France
| | - Patrick Chaynes
- Department of Anatomy, Toulouse Faculty of Medicine, Toulouse, France
| | - Patrice Péran
- Toulouse NeuroImaging Center, University of Toulouse Paul Sabatier-INSERM, Toulouse, France
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