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Wang N, Maharjan S, Tsai AP, Lin PB, Qi Y, Wallace A, Jewett M, Liu F, Landreth GE, Oblak AL. Integrating multimodality magnetic resonance imaging to the Allen Mouse Brain Common Coordinate Framework. NMR IN BIOMEDICINE 2023; 36:e4887. [PMID: 36454009 PMCID: PMC10106385 DOI: 10.1002/nbm.4887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 05/07/2023]
Abstract
High-resolution magnetic resonance imaging (MRI) affords unique image contrasts to nondestructively probe the tissue microstructure; validation of MRI findings with conventional histology is essential to better understand the MRI contrasts. However, the dramatic difference in the spatial resolution and image contrast of these two techniques impedes accurate comparison between MRI metrics and traditional histology. To better validate various MRI metrics, we acquired whole mouse brain multigradient recalled-echo and multishell diffusion MRI datasets at 25-μm isotropic resolution. The recently developed Allen Mouse Brain Common Coordinate Framework (CCFv3) provides opportunities to integrate multimodal and multiscale datasets of the whole mouse brain in a common three-dimensional (3D) space. The T2*, quantitative susceptibility mapping, diffusion tensor imaging, and neurite orientation dispersion and density imaging parameters were compared with both serial two-photon tomography images and 3D Nissl staining images in the CCFv3 at the same spatial resolution. The correlation between MRI and Nissl staining strongly depends on different metrics and different regions of the brain. Integrating different imaging modalities to the same space may substantially improve our understanding of the complexity of the brain at different scales.
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Affiliation(s)
- Nian Wang
- Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, Indiana, USA
| | - Surendra Maharjan
- Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, Indiana, USA
| | - Andy P. Tsai
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, Indiana, USA
| | - Peter B. Lin
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, Indiana, USA
| | - Yi Qi
- Center for In Vivo Microscopy, Department of Radiology, Duke University, Durham, North Carolina, USA
| | - Abigail Wallace
- Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, Indiana, USA
| | - Megan Jewett
- Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, Indiana, USA
| | - Fang Liu
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Gary E. Landreth
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, Indiana, USA
| | - Adrian L. Oblak
- Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University, Indianapolis, Indiana, USA
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Balcaen T, Piens C, Mwema A, Chourrout M, Vandebroek L, Des Rieux A, Chauveau F, De Borggraeve WM, Hoffmann D, Kerckhofs G. Revealing the three-dimensional murine brain microstructure by contrast-enhanced computed tomography. Front Neurosci 2023; 17:1141615. [PMID: 37034159 PMCID: PMC10076597 DOI: 10.3389/fnins.2023.1141615] [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: 01/10/2023] [Accepted: 03/08/2023] [Indexed: 04/11/2023] Open
Abstract
To improve our understanding of the brain microstructure, high-resolution 3D imaging is used to complement classical 2D histological assessment techniques. X-ray computed tomography allows high-resolution 3D imaging, but requires methods for enhancing contrast of soft tissues. Applying contrast-enhancing staining agents (CESAs) ameliorates the X-ray attenuating properties of soft tissue constituents and is referred to as contrast-enhanced computed tomography (CECT). Despite the large number of chemical compounds that have successfully been applied as CESAs for imaging brain, they are often toxic for the researcher, destructive for the tissue and without proper characterization of affinity mechanisms. We evaluated two sets of chemically related CESAs (organic, iodinated: Hexabrix and CA4+ and inorganic polyoxometalates: 1:2 hafnium-substituted Wells-Dawson phosphotungstate and Preyssler anion), for CECT imaging of healthy murine hemispheres. We then selected the CESA (Hexabrix) that provided the highest contrast between gray and white matter and applied it to a cuprizone-induced demyelination model. Differences in the penetration rate, effect on tissue integrity and affinity for tissue constituents have been observed for the evaluated CESAs. Cuprizone-induced demyelination could be visualized and quantified after Hexabrix staining. Four new non-toxic and non-destructive CESAs to the field of brain CECT imaging were introduced. The added value of CECT was shown by successfully applying it to a cuprizone-induced demyelination model. This research will prove to be crucial for further development of CESAs for ex vivo brain CECT and 3D histopathology.
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Affiliation(s)
- Tim Balcaen
- MolDesignS, Sustainable Chemistry for Metals and Molecules, Department of Chemistry, KU Leuven, Leuven, Belgium
- ContrasT Team, Institute of Mechanics, Materials and Civil Engineering, Mechatronic, Electrical Energy and Dynamic Systems, UCLouvain, Louvain-la-Neuve, Belgium
- Pole of Morphology, Institute of Experimental and Clinical Research, UCLouvain, Brussels, Belgium
| | - Catherine Piens
- ContrasT Team, Institute of Mechanics, Materials and Civil Engineering, Mechatronic, Electrical Energy and Dynamic Systems, UCLouvain, Louvain-la-Neuve, Belgium
| | - Ariane Mwema
- Advanced Drug Delivery and Biomaterials, UCLouvain, Brussels, Belgium
- Bioanalysis and Pharmacology of Bioactive Lipids, UCLouvain, Brussels, Belgium
| | - Matthieu Chourrout
- Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Centre de Recherche en Neurosciences de Lyon U1028 UMR 5292, Bron, France
| | - Laurens Vandebroek
- Laboratory of Biomolecular Modelling and Design (LBMD), Biochemistry, Molecular and Structural Biology, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Anne Des Rieux
- Advanced Drug Delivery and Biomaterials, UCLouvain, Brussels, Belgium
| | - Fabien Chauveau
- Université Claude Bernard Lyon 1, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Centre de Recherche en Neurosciences de Lyon U1028 UMR 5292, Bron, France
| | - Wim M. De Borggraeve
- MolDesignS, Sustainable Chemistry for Metals and Molecules, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Delia Hoffmann
- Pole of Morphology, Institute of Experimental and Clinical Research, UCLouvain, Brussels, Belgium
- Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
- Skeletal Biology and Engineering Research Center, KU Leuven, Leuven, Belgium
| | - Greet Kerckhofs
- ContrasT Team, Institute of Mechanics, Materials and Civil Engineering, Mechatronic, Electrical Energy and Dynamic Systems, UCLouvain, Louvain-la-Neuve, Belgium
- Pole of Morphology, Institute of Experimental and Clinical Research, UCLouvain, Brussels, Belgium
- Department Materials Engineering, KU Leuven, Leuven, Belgium
- *Correspondence: Greet Kerckhofs,
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Censoni L, Halje P, Axelsson J, Skovgård K, Ramezani A, Malinina E, Petersson P. Verification of multi-structure targeting in chronic microelectrode brain recordings from CT scans. J Neurosci Methods 2022; 382:109719. [PMID: 36195238 DOI: 10.1016/j.jneumeth.2022.109719] [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: 03/23/2022] [Revised: 09/07/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022]
Abstract
BACKGROUND Large-scale microelectrode recordings offer a unique opportunity to study neurophysiological processes at the network level with single cell resolution. However, in the small brains of many experimental animals, it is often technically challenging to verify the correct targeting of the intended structures, which inherently limits the reproducibility of acquired data. NEW METHOD To mitigate this problem, we have developed a method to programmatically segment the trajectory of electrodes arranged in larger arrays from acquired CT-images and thereby determine the position of individual recording tips with high spatial resolution, while also allowing for coregistration with an anatomical atlas, without pre-processing of the animal samples or post-imaging histological analyses. RESULTS Testing the technical limitations of the developed method, we found that the choice of scanning angle influences the achievable spatial resolution due to shadowing effects caused by the electrodes. However, under optimal acquisition conditions, individual electrode tip locations within arrays with 250 µm inter-electrode spacing were possible to reliably determine. COMPARISON TO EXISTING METHODS Comparison to a histological verification method suggested that, under conditions where individual wires are possible to track in slices, a 90% correspondence could be achieved in terms of the number of electrodes groups that could be reliably assigned to the same anatomical structure. CONCLUSIONS The herein reported semi-automated procedure to verify anatomical targeting of brain structures in the rodent brain could help increasing the quality and reproducibility of acquired neurophysiological data by reducing the risk of assigning recorded brain activity to incorrectly identified anatomical locations. DATA AVAILABILITY The tools developed in this study are freely available as a software package at: https://github.com/NRC-Lund/ct-tools.
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Affiliation(s)
- Luciano Censoni
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - Pär Halje
- The Group for Integrative Neurophysiology and Neurotechnology, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Jan Axelsson
- Department of Radiation Science, Umeå University, Umeå, Sweden
| | - Katrine Skovgård
- The Group for Integrative Neurophysiology and Neurotechnology, Department of Experimental Medical Science, Lund University, Lund, Sweden; Basal Ganglia Pathophysiology Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Arash Ramezani
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - Evgenya Malinina
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - Per Petersson
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden; The Group for Integrative Neurophysiology and Neurotechnology, Department of Experimental Medical Science, Lund University, Lund, Sweden.
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High-resolution micro-CT for 3D infarct characterization and segmentation in mice stroke models. Sci Rep 2022; 12:17471. [PMID: 36261475 PMCID: PMC9582034 DOI: 10.1038/s41598-022-21494-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 09/28/2022] [Indexed: 01/12/2023] Open
Abstract
Characterization of brain infarct lesions in rodent models of stroke is crucial to assess stroke pathophysiology and therapy outcome. Until recently, the analysis of brain lesions was performed using two techniques: (1) histological methods, such as TTC (Triphenyltetrazolium chloride), a time-consuming and inaccurate process; or (2) MRI imaging, a faster, 3D imaging method, that comes at a high cost. In the last decade, high-resolution micro-CT for 3D sample analysis turned into a simple, fast, and cheaper solution. Here, we successfully describe the application of brain contrasting agents (Osmium tetroxide and inorganic iodine) for high-resolution micro-CT imaging for fine location and quantification of ischemic lesion and edema in mouse preclinical stroke models. We used the intraluminal transient MCAO (Middle Cerebral Artery Occlusion) mouse stroke model to identify and quantify ischemic lesion and edema, and segment core and penumbra regions at different time points after ischemia, by manual and automatic methods. In the transient-ischemic-attack (TIA) mouse model, we can quantify striatal myelinated fibers degeneration. Of note, whole brain 3D reconstructions allow brain atlas co-registration, to identify the affected brain areas, and correlate them with functional impairment. This methodology proves to be a breakthrough in the field, by providing a precise and detailed assessment of stroke outcomes in preclinical animal studies.
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Simcock IC, Shelmerdine SC, Langan D, Anna G, Sebire NJ, Arthurs OJ. Micro-CT yields high image quality in human fetal post-mortem imaging despite maceration. BMC Med Imaging 2021; 21:128. [PMID: 34429085 PMCID: PMC8383392 DOI: 10.1186/s12880-021-00658-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 08/01/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Current clinical post-mortem imaging techniques do not provide sufficiently high-resolution imaging for smaller fetuses after pregnancy loss. Post-mortem micro-CT is a non-invasive technique that can deliver high diagnostic accuracy for these smaller fetuses. The purpose of the study is to identify the main predictors of image quality for human fetal post-mortem micro-CT imaging. METHODS Human fetuses were imaged using micro-CT following potassium tri-iodide tissue preparation, and axial head and chest views were assessed for image quality on a Likert scale by two blinded radiologists. Simple and multivariable linear regression models were performed with demographic details, iodination, tissue maceration score and imaging parameters as predictor variables. RESULTS 258 fetuses were assessed, with median weight 41.7 g (2.6-350 g) and mean gestational age 16 weeks (11-24 weeks). A high image quality score (> 6.5) was achieved in 95% of micro-CT studies, higher for the head (median = 9) than chest (median = 8.5) imaging. The strongest negative predictors of image quality were increasing maceration and body weight (p < 0.001), with number of projections being the best positive imaging predictor. CONCLUSIONS High micro-CT image quality score is achievable following early pregnancy loss despite fetal maceration, particularly in smaller fetuses where conventional autopsy may be particularly challenging. These findings will help establish clinical micro-CT imaging services, addressing the need for less invasive fetal autopsy methods.
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Affiliation(s)
- Ian Craig Simcock
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK.
- Great Ormond Street Hospital for Children, UCL Great Ormond Street Institute of Child Health, London, UK.
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK.
| | - Susan Cheng Shelmerdine
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK
- Great Ormond Street Hospital for Children, UCL Great Ormond Street Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - Dean Langan
- Great Ormond Street Hospital for Children, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Guy Anna
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK
- Great Ormond Street Hospital for Children, UCL Great Ormond Street Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - Neil James Sebire
- Great Ormond Street Hospital for Children, UCL Great Ormond Street Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
- Department of Histopathology, Great Ormond Street Hospital for Children, London, UK
| | - Owen John Arthurs
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK
- Great Ormond Street Hospital for Children, UCL Great Ormond Street Institute of Child Health, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
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O. J, Kwon HJ, Cho TH, Woo SH, Rhee YH, Yang HM. Micro-computed tomography with contrast enhancement: An excellent technique for soft tissue examination in humans. PLoS One 2021; 16:e0254264. [PMID: 34242334 PMCID: PMC8270403 DOI: 10.1371/journal.pone.0254264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 06/23/2021] [Indexed: 11/19/2022] Open
Abstract
Manual dissection and histologic examination are commonly used to investigate human structures, but there are limitations in the damage caused to delicate structures or the provision of limited information. Micro-computed tomography (microCT) enables a three-dimensional volume-rendered observation of the sample without destruction and deformation, but it can only visualize hard tissues in general. Therefore, contrast-enhancing agents are needed to help in visualizing soft tissue. This study aimed to introduce microCT with phosphotungstic acid preparation (PTA-microCT) by applying the method to different types of human tissue. Specimens from human cadavers were used to examine the orbicularis retaining ligament (ORL), nasolabial fold (NLF), and the calcaneal tunnel of the sole. Using PTA-microCT, relevant information of human structures was identified. In the ORL study, tiny and delicate ligamentous fibers were visualized in detail with multidirectional continuity. In the NLF study, complex structural formation consisting of various types of soft tissue were investigated comprehensively. In the calcaneal tunnel study, the space surrounded by diverse features and its inner vulnerable structures were examined without damage. Consequently, we successfully applied the PTA-microCT technique to the analysis of specific human soft tissue structures that are challenging to analyze by conventional methods.
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Affiliation(s)
- Jehoon O.
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyun-Jin Kwon
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Tae-Hyeon Cho
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Seung Hoon Woo
- Beckman Laser Institute Korea, Dankook University College of Medicine, Cheonan, Republic of Korea
| | - Yun-Hee Rhee
- Beckman Laser Institute Korea, Dankook University College of Medicine, Cheonan, Republic of Korea
| | - Hun-Mu Yang
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
- Surgical Anatomy Education Centre at the Yonsei University College of Medicine, Seoul, Republic of Korea
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Chen KC, Song ZM, Croaker GD. Brain size reductions associated with endothelin B receptor mutation, a cause of Hirschsprung's disease. BMC Neurosci 2021; 22:42. [PMID: 34147087 PMCID: PMC8214790 DOI: 10.1186/s12868-021-00646-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 06/08/2021] [Indexed: 01/03/2023] Open
Abstract
Background ETB has been reported to regulate neurogenesis and vasoregulation in foetal development. Its dysfunction was known to cause HSCR, an aganglionic colonic disorder with syndromic forms reported to associate with both small heads and developmental delay. We therefore asked, "is CNS maldevelopment a more general feature of ETB mutation?" To investigate, we reviewed the micro-CT scans of an ETB−/− model animal, sl/sl rat, and quantitatively evaluated the structural changes of its brain constituents. Methods Eleven neonatal rats generated from ETB+/− cross breeding were sacrificed. Micro-CT scans were completed following 1.5% iodine-staining protocols. All scans were reviewed for morphological changes. Selected organs were segmented semi-automatically post-NLM filtering: TBr, T-CC, T-CP, OB, Med, Cer, Pit, and S&I Col. Volumetric measurements were made using Drishti rendering software. Rat genotyping was completed following analysis. Statistical comparisons on organ volume, organ growth rate, and organ volume/bodyweight ratios were made between sl/sl and the control groups based on autosomal recessive inheritance. One-way ANOVA was also performed to evaluate potential dose-dependent effect. Results sl/sl rat has 16.32% lower body weight with 3.53% lower growth rate than the control group. Gross intracranial morphology was preserved in sl/sl rats. However, significant volumetric reduction of 20.33% was detected in TBr; similar reductions were extended to the measurements of T-CC, T-CP, OB, Med, and Pit. Consistently, lower brain and selected constituent growth rates were detected in sl/sl rat, ranging from 6.21% to 11.51% reduction. Lower organ volume/bodyweight ratio was detected in sl/sl rats, reflecting disproportional neural changes with respect to body size. No consistent linear relationships exist between ETB copies and intracranial organ size or growth rates. Conclusion Although ETB−/− mutant has a normal CNS morphology, significant size reductions in brain and constituents were detected. These structural changes likely arise from a combination of factors secondary to dysfunctional ET-1/ET-3/ETB signalling, including global growth impairment from HSCR-induced malnutrition and dysregulations in the neurogenesis, angiogenesis, and cerebral vascular control. These changes have important clinical implications, such as autonomic dysfunction or intellectual delay. Although further human study is warranted, our study suggested comprehensive managements are required for HSCR patients, at least in ETB−/− subtype. Supplementary Information The online version contains supplementary material available at 10.1186/s12868-021-00646-z.
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Affiliation(s)
- Ko-Chin Chen
- Medical School, Australian National University, Canberra, ACT, 2601, Australia.
| | - Zan-Min Song
- Medical School, Australian National University, Canberra, ACT, 2601, Australia
| | - Geoffrey D Croaker
- Medical School, Australian National University, Canberra, ACT, 2601, Australia.,The Canberra Hospital, Yamba Drive, Garran, ACT, 2605, Australia
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8
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Simcock IC, Shelmerdine SC, Hutchinson JC, Sebire NJ, Arthurs OJ. Human fetal whole-body postmortem microfocus computed tomographic imaging. Nat Protoc 2021; 16:2594-2614. [PMID: 33854254 DOI: 10.1038/s41596-021-00512-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 01/05/2021] [Indexed: 02/02/2023]
Abstract
Perinatal autopsy is the standard method for investigating fetal death; however, it requires dissection of the fetus. Human fetal microfocus computed tomography (micro-CT) provides a generally more acceptable and less invasive imaging alternative for bereaved parents to determine the cause of early pregnancy loss compared with conventional autopsy techniques. In this protocol, we describe the four main stages required to image fetuses using micro-CT. Preparation of the fetus includes staining with the contrast agent potassium triiodide and takes 3-19 d, depending on the size of the fetus and the time taken to obtain consent for the procedure. Setup for imaging requires appropriate positioning of the fetus and takes 1 h. The actual imaging takes, on average, 2 h 40 min and involves initial test scans followed by high-definition diagnostic scans. Postimaging, 3 d are required to postprocess the fetus, including removal of the stain, and also to undertake artifact recognition and data transfer. This procedure produces high-resolution isotropic datasets, allowing for radio-pathological interpretations to be made and long-term digital archiving for re-review and data sharing, where required. The protocol can be undertaken following appropriate training, which includes both the use of micro-CT techniques and handling of postmortem tissue.
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Affiliation(s)
- Ian C Simcock
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK.,UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - Susan C Shelmerdine
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK.,UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - J Ciaran Hutchinson
- UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK.,Department of Histopathology, Great Ormond Street Hospital for Children, London, UK
| | - Neil J Sebire
- UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, London, UK.,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK.,Department of Histopathology, Great Ormond Street Hospital for Children, London, UK
| | - Owen J Arthurs
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK. .,UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, London, UK. .,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK.
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Doost A, Arnolda L. Iodine staining outperforms phosphotungstic acid in high-resolution micro-CT scanning of post-natal mice cardiac structures. J Med Imaging (Bellingham) 2021; 8:027001. [PMID: 33778096 DOI: 10.1117/1.jmi.8.2.027001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/12/2021] [Indexed: 01/21/2023] Open
Abstract
Purpose: Micro-computed tomography (micro-CT) scan provides high-resolution three-dimensional images of mineralized tissues in small animal models. Contrast enhancement is essential to visualize non-mineralized tissues with micro-CT scan. We attempted to compare the two most common contrast agents to stain and image mouse cardiac structures. Approach: Ex-vivo micro-CT scan images of the mouse hearts were obtained following staining by potassium iodide or phosphotungstic acid (PTA). PTA-stained samples were imaged after various durations following staining (14 days, 25 days, 187 days, and 780 days), whereas iodine-stained samples were imaged after 72 hours. We compared median staining intensity between PTA and iodine at 0.1-mm intervals from the edge using the Mann Whitney test with correction for multiple comparisons. Results: Sixty post-natal mice hearts were stained with either PTA or iodine and imaged using micro-CT scan. Iodine proved to be faster and more uniform in complete enhancement of cardiac tissue in as short as 72 h, whereas PTA required a significantly longer time period to penetrate mouse cardiac structure ( > 150 days ). Median staining intensity with iodine was strongly higher than that with PTA from 0.1- to 1.5-mm distance from the epicardial edge (2-tailed P value < 0.01 or lower throughout). Conclusions: Iodine-stained soft tissue imaging by micro-CT scan provides a non-destructive, efficient, and accurate visualization tool for anatomical analysis of animal heart models of human cardiovascular conditions. Iodine is more efficient compared to PTA to achieve complete murine myocardial staining in a significantly shorter time period.
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Affiliation(s)
- Ata Doost
- Australian National University Medical School, Canberra, Australian Capital Territory, Australia.,Fiona Stanley Hospital, Cardiology Department, Murdoch, Western Australia, Australia
| | - Leonard Arnolda
- Australian National University Medical School, Canberra, Australian Capital Territory, Australia.,University of Wollongong, Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia
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10
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Llambrich S, Wouters J, Himmelreich U, Dierssen M, Sharpe J, Gsell W, Martínez-Abadías N, Vande Velde G. ViceCT and whiceCT for simultaneous high-resolution visualization of craniofacial, brain and ventricular anatomy from micro-computed tomography. Sci Rep 2020; 10:18772. [PMID: 33128010 PMCID: PMC7599226 DOI: 10.1038/s41598-020-75720-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
Up to 40% of congenital diseases present disturbances of brain and craniofacial development resulting in simultaneous alterations of both systems. Currently, the best available method to preclinically visualize the brain and the bones simultaneously is to co-register micro-magnetic resonance (µMR) and micro-computed tomography (µCT) scans of the same specimen. However, this requires expertise and access to both imaging techniques, dedicated software and post-processing knowhow. To provide a more affordable, reliable and accessible alternative, recent research has focused on optimizing a contrast-enhanced µCT protocol using iodine as contrast agent that delivers brain and bone images from a single scan. However, the available methods still cannot provide the complete visualization of both the brain and whole craniofacial complex. In this study, we have established an optimized protocol to diffuse the contrast into the brain that allows visualizing the brain parenchyma and the complete craniofacial structure in a single ex vivo µCT scan (whiceCT). In addition, we have developed a new technique that allows visualizing the brain ventricles using a bilateral stereotactic injection of iodine-based contrast (viceCT). Finally, we have tested both techniques in a mouse model of Down syndrome, as it is a neurodevelopmental disorder with craniofacial, brain and ventricle defects. The combined use of viceCT and whiceCT provides a complete visualization of the brain and bones with intact craniofacial structure of an adult mouse ex vivo using a single imaging modality.
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Affiliation(s)
- Sergi Llambrich
- Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Herestraat 49 O&N1 box 505, 3000, Leuven, Belgium.,Molecular Small Animal Imaging Centre (MoSAIC), KU Leuven, Leuven, Belgium
| | - Jens Wouters
- Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Herestraat 49 O&N1 box 505, 3000, Leuven, Belgium.,Molecular Small Animal Imaging Centre (MoSAIC), KU Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Herestraat 49 O&N1 box 505, 3000, Leuven, Belgium.,Molecular Small Animal Imaging Centre (MoSAIC), KU Leuven, Leuven, Belgium
| | - Mara Dierssen
- Centre for Genomic Regulation (CRG, The Barcelona Institute of Science and Technology, 08003, Barcelona, Spain.,Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain
| | - James Sharpe
- EMBL Barcelona, European Molecular Biology Laboratory, Barcelona, Spain Institució Catalana de Recerca I Estudis Avançats (ICREA), Barcelona, Spain
| | - Willy Gsell
- Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Herestraat 49 O&N1 box 505, 3000, Leuven, Belgium.,Molecular Small Animal Imaging Centre (MoSAIC), KU Leuven, Leuven, Belgium
| | - Neus Martínez-Abadías
- GREAB-Research Group in Biological Anthropology. Department of Evolutionary Biology, Ecology and Environmental Sciences, BEECA. Universitat de Barcelona, Barcelona, Spain
| | - Greetje Vande Velde
- Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Herestraat 49 O&N1 box 505, 3000, Leuven, Belgium. .,Molecular Small Animal Imaging Centre (MoSAIC), KU Leuven, Leuven, Belgium.
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Acute administration of diazepam or midazolam minimally alters long-term neuropathological effects in the rat brain following acute intoxication with diisopropylfluorophosphate. Eur J Pharmacol 2020; 886:173538. [PMID: 32898549 DOI: 10.1016/j.ejphar.2020.173538] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 12/30/2022]
Abstract
Acute intoxication with organophosphorus cholinesterase inhibitors (OPs) can trigger seizures that rapidly progress to life-threatening status epilepticus. Diazepam, long considered the standard of care for treating OP-induced seizures, is being replaced by midazolam. Whether midazolam is more effective than diazepam in mitigating the persistent effects of acute OP intoxication has not been rigorously evaluated. We compared the efficacy of diazepam vs. midazolam in preventing persistent neuropathology in adult male Sprague-Dawley rats acutely intoxicated with the OP diisopropylfluorophosphate (DFP). Subjects were administered pyridostigmine bromide (0.1 mg/kg, i.p.) 30 min prior to injection with DFP (4 mg/kg, s.c.) or vehicle (saline) followed 1 min later by atropine sulfate (2 mg/kg, i.m.) and pralidoxime (25 mg/kg, i.m.), and 40 min later by diazepam (5 mg/kg, i.p.), midazolam (0.73 mg/kg, i.m.), or vehicle. At 3 and 6 months post-exposure, neurodegeneration, reactive astrogliosis, microglial activation, and oxidative stress were assessed in multiple brain regions using quantitative immunohistochemistry. Brain mineralization was evaluated by in vivo micro-computed tomography (micro-CT). Acute DFP intoxication caused persistent neurodegeneration, neuroinflammation, and brain mineralization. Midazolam transiently mitigated neurodegeneration, and both benzodiazepines partially protected against reactive astrogliosis in a brain region-specific manner. Neither benzodiazepine attenuated microglial activation or brain mineralization. These findings indicate that neither benzodiazepine effectively protects against persistent neuropathological changes, and suggest that midazolam is not significantly better than diazepam. Overall, this study highlights the need for improved neuroprotective strategies for treating humans in the event of a chemical emergency involving OPs.
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Simcock IC, Hutchinson JC, Shelmerdine SC, Matos JN, Sebire NJ, Fuentes VL, Arthurs OJ. Investigation of optimal sample preparation conditions with potassium triiodide and optimal imaging settings for microfocus computed tomography of excised cat hearts. Am J Vet Res 2020; 81:326-333. [PMID: 32228254 DOI: 10.2460/ajvr.81.4.326] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine optimal sample preparation conditions with potassium triiodide (I2KI) and optimal imaging settings for microfocus CT (micro-CT) of excised cat hearts. SAMPLE 7 excised hearts (weight range, 10 to 17.6 g) obtained from healthy adult cats after euthanasia by IV injection of pentobarbital sodium. PROCEDURES Following excision, the hearts were preserved in 10% formaldehyde solution. Six hearts were immersed in 1.25% I2KI solution (n = 3) or 2.5% I2KI solution (3) for a 12-day period. Micro-CT images were acquired at time 0 (prior to iodination) then approximately every 24 and 48 hours thereafter to determine optimal sample preparation conditions (ie, immersion time and concentration of I2KI solution). Identified optimal conditions were then used to prepare the seventh heart for imaging; changes in voltage, current, exposure time, and gain on image quality were evaluated to determine optimal settings (ie, maximal signal-to-noise and contrast-to-noise ratios). Images were obtained at a voxel resolution of 30 μm. A detailed morphological assessment of the main cardiac structures of the seventh heart was then performed. RESULTS Immersion in 2.5% I2KI solution for 48 hours was optimal for sample preparation. The optimal imaging conditions included a tube voltage of 100 kV, current of 150 μA, and exposure time of 354 milliseconds; scan duration was 12 minutes. CONCLUSIONS AND CLINICAL RELEVANCE Results provided an optimal micro-CT imaging protocol for excised cat hearts prepared with I2KI solution that could serve as a basis for future studies of micro-CT for high resolution 3-D imaging of cat hearts.
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Barbone GE, Bravin A, Mittone A, Kraiger MJ, Hrabě de Angelis M, Bossi M, Ballarini E, Rodriguez-Menendez V, Ceresa C, Cavaletti G, Coan P. Establishing sample-preparation protocols for X-ray phase-contrast CT of rodent spinal cords: Aldehyde fixations and osmium impregnation. J Neurosci Methods 2020; 339:108744. [DOI: 10.1016/j.jneumeth.2020.108744] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 12/14/2022]
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