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Yang L, Li M, Zhan Y, Feng X, Lu Y, Li M, Zhuang Y, Lei J, Zhao H. The Impact of Ischemic Stroke on Gray and White Matter Injury Correlated With Motor and Cognitive Impairments in Permanent MCAO Rats: A Multimodal MRI-Based Study. Front Neurol 2022; 13:834329. [PMID: 35309583 PMCID: PMC8924049 DOI: 10.3389/fneur.2022.834329] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/19/2022] [Indexed: 01/12/2023] Open
Abstract
Background Identifying the alterations of the cerebral gray and white matter is an important prerequisite for developing potential pharmacological therapy for stroke. This study aimed to assess the changes of gray and white matter after permanent middle cerebral artery occlusion (pMCAO) in rats using magnetic resonance imaging (MRI), and to correlate them with the behavior performance. Methods Rats were subjected to pMCAO or sham surgery and reared for 30 days. Motor and cognitive function of the rats were examined by gait and Morris water maze (MWM) tests, respectively. Multimodal MRI was conducted to examine the functional and structural changes of the gray and white matter followed with luxol fast blue (LFB) staining. Results The gait and MWM tests revealed significant motor and cognitive dysfunction in pMCAO rats, respectively. Magnetic resonance angiography presented abnormal intracranial arteries in pMCAO rats with reduced signal intensity of the anterior cerebral artery, anterior communicating cerebral artery, internal carotid artery, and increased basilar artery vessel signal compared with sham rats. Arterial spin labeling confirmed the decreased cerebral blood flow in the infarcted sensorimotor cortex and striatum. Structural T2-weighted imaging and T2 mapping showed brain atrophy and elevation of T2 value in the gray (sensorimotor cortex, striatum) and white (external capsule, internal capsule) matter of pMCAO rats. The results from diffusion tensor imaging (DTI) corresponded well with LFB staining showing reduced relative FA accompanied with increased relative AD and RD in the gray and white matter of pMCAO rats compared with sham rats. Fiber tracking derived from DTI further observed significantly reduced fiber density and length in the corresponding brain regions of pMCAO rats compared with sham rats. Specially, the DTI parameters (especially FA) in the relevant gray matter and white matter significantly correlated with the behavior performance in the gait and MWM tests. Conclusion Collectively, the gray and white matter damages could be non-invasively monitored in pMCAO rats by multimodal MRI. DTI-derived parameters, particularly the FA, might be a good imaging index to stage gray and white matter damages associated with post-stroke motor and cognitive impairments.
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Affiliation(s)
- Le Yang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Manzhong Li
- Department of Pharmacy, Beijing Shijitan Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Bio-characteristic Profiling for Evaluation of Rational Drug Use, Beijing, China
| | - Yu Zhan
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Xuefeng Feng
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Yun Lu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Mingcong Li
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Yuming Zhuang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Jianfeng Lei
- Medical Imaging Laboratory of Core Facility Center, Capital Medical University, Beijing, China
| | - Hui Zhao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
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2
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Kang M, Jin S, Cho H. MRI investigation of vascular remodeling for heterogeneous edema lesions in subacute ischemic stroke rat models: Correspondence between cerebral vessel structure and function. J Cereb Blood Flow Metab 2021; 41:3273-3287. [PMID: 34233533 PMCID: PMC8669276 DOI: 10.1177/0271678x211029197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The spatial heterogeneity in the temporal occurrence of pseudo-normalization of MR apparent diffusion coefficient values for ischemic lesions may be related to morphological and functional vascular remodeling. As the area of accelerated pseudo-normalization tends to expand faster and more extensively into the chronic stage, detailed vascular characterization of such areas is necessary. During the subacute stage of transient middle cerebral artery occlusion rat models, the morphological size of the macrovasculature, microvascular vessel size index (VSI), and microvessel density (MVD) were quantified along with functional perfusion measurements of the relative cerebral blood flow (rCBF) and mean transit time (rMTT) of the corresponding areas (33 cases for each parameter). When compared with typical pseudo-normalization lesions, early pseudo-normalization lesions exhibited larger VSI and rCBF (p < 0.001) at reperfusion days 4 and 7, along with reduced MVD and elongated rMTT (p < 0.001) at reperfusion days 1, 4, and 7. The group median VSI and rCBF exhibited a strong positive correlation (r = 0.92), and the corresponding MVD and rMTT showed a negative correlation (r = -0.48). Light sheet fluorescence microscopy images were used to quantitatively validate the corresponding MRI-derived microvascular size, density, and cerebral blood volume.
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Affiliation(s)
| | | | - HyungJoon Cho
- HyungJoon Cho, Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Unist-gil 50 (100 Banyeon-ri), Eonyang-eup, Uljugun, Ulsan Metropolitan City 689-798, South Korea.
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3
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Arnold SA, Platt SR, Gendron KP, West FD. Imaging Ischemic and Hemorrhagic Disease of the Brain in Dogs. Front Vet Sci 2020; 7:279. [PMID: 32528985 PMCID: PMC7266937 DOI: 10.3389/fvets.2020.00279] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/27/2020] [Indexed: 01/12/2023] Open
Abstract
Strokes, both ischemic and hemorrhagic, are the most common underlying cause of acute, non-progressive encephalopathy in dogs. In effect, substantial information detailing the underlying causes and predisposing factors, affected vessels, imaging features, and outcomes based on location and extent of injury is available. The features of canine strokes on both computed tomography (CT) and magnetic resonance imaging (MRI) have been described in numerous studies. This summary article serves as a compilation of these various descriptions. Drawing from the established and emerging stroke evaluation sequences used in the investigation of strokes in humans, this summary describes all theoretically available sequences. Particular detail is given to logistics of image acquisition, description of imaging findings, and each sequence's advantages and disadvantages. As the imaging features of both forms of strokes are highly representative of the underlying pathophysiologic stages in the hours to months following stroke onset, the descriptions of strokes at various stages are also discussed. It is unlikely that canine strokes can be diagnosed within the same rapid time frame as human strokes, and therefore the opportunity for thrombolytic intervention in ischemic strokes is unattainable. However, a thorough understanding of the appearance of strokes at various stages can aid the clinician when presented with a patient that has developed a stroke in the days or weeks prior to evaluation. Additionally, investigation into new imaging techniques may increase the sensitivity and specificity of stroke diagnosis, as well as provide new ways to monitor strokes over time.
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Affiliation(s)
- Susan A Arnold
- Department of Veterinary Clinical Sciences, University of Minnesota Twin Cities, St. Paul, MN, United States
| | - Simon R Platt
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, United States
| | - Karine P Gendron
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, United States
| | - Franklin D West
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, United States
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4
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Kang M, Jin S, Lee D, Cho H. MRI Visualization of Whole Brain Macro- and Microvascular Remodeling in a Rat Model of Ischemic Stroke: A Pilot Study. Sci Rep 2020; 10:4989. [PMID: 32193454 PMCID: PMC7081185 DOI: 10.1038/s41598-020-61656-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 02/28/2020] [Indexed: 01/14/2023] Open
Abstract
Using superparamagnetic iron oxide nanoparticles (SPION) as a single contrast agent, we investigated dual contrast cerebrovascular magnetic resonance imaging (MRI) for simultaneously monitoring macro- and microvasculature and their association with ischemic edema status (via apparent diffusion coefficient [ADC]) in transient middle cerebral artery occlusion (tMCAO) rat models. High-resolution T1-contrast based ultra-short echo time MR angiography (UTE-MRA) visualized size remodeling of pial arteries and veins whose mutual association with cortical ischemic edema status is rarely reported. ΔR2-ΔR2*-MRI-derived vessel size index (VSI) and density indices (Q and MVD) mapped morphological changes of microvessels occurring in subcortical ischemic edema lesions. In cortical ischemic edema lesions, significantly dilated pial veins (p = 0.0051) and thinned pial arteries (p = 0.0096) of ipsilateral brains compared to those of contralateral brains were observed from UTE-MRAs. In subcortical regions, ischemic edema lesions had a significantly decreased Q and MVD values (p < 0.001), as well as increased VSI values (p < 0.001) than normal subcortical tissues in contralateral brains. This pilot study suggests that MR-based morphological vessel changes, including but not limited to venous blood vessels, are directly related to corresponding tissue edema status in ischemic stroke rat models.
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Affiliation(s)
- MungSoo Kang
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - SeokHa Jin
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - DongKyu Lee
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - HyungJoon Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
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5
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Lepore MG, Buscemi L, Hirt L, Lei H. Metabolic fingerprints discriminating severity of acute ischemia using in vivo high-field 1 H magnetic resonance spectroscopy. J Neurochem 2019; 152:252-262. [PMID: 31758862 DOI: 10.1111/jnc.14922] [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: 09/16/2019] [Revised: 11/17/2019] [Accepted: 11/19/2019] [Indexed: 11/28/2022]
Abstract
Despite the improving imaging techniques, it remains challenging to produce magnetic resonance (MR) imaging fingerprints depicting severity of acute ischemia. The aim of this study was to evaluate the potential of the overall high-field 1 H MR Spectroscopy (1 H-MRS) neurochemical profile as a metabolic signature for acute ischemia severity in rodent brains. We modeled global ischemia with one-stage 4-vessel-occlusion (4VO) in rats. Vascular structures were assessed immediately by magnetic resonance angiography. The neurochemical responses in the bilateral cortex were measured 1 h after stroke onset by 1 H-MRS. Then we used Partial-Least-Squares discriminant analysis on the overall neurochemical profiles to seek metabolic signatures for ischemic severity subgroups. This approach was further tested on neurochemical profiles of mouse striatum 1 h after permanent middle cerebral artery occlusion, where vascular blood flow was monitored by laser Doppler. Magnetic resonance angiography identified successful 4VO from controls and incomplete global ischemia (e.g., 3VO). 1 H-MR spectra of rat cortex after 4VO showed a specific metabolic pattern, distinct from that of respective controls and rats with 3VO. Partial-Least-Squares discriminant analysis on the overall neurochemical profiles revealed metabolic signatures of acute ischemia that may be extended to mice after permanent middle cerebral artery occlusion. Fingerprinting severity of acute ischemia using neurochemical information may improve MR diagnosis in stroke patients.
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Affiliation(s)
- Mario G Lepore
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Lara Buscemi
- Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Lorenz Hirt
- Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Hongxia Lei
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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6
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Zhan Y, Li MZ, Yang L, Feng XF, Zhang QX, Zhang N, Zhao YY, Zhao H. An MRI Study of Neurovascular Restorative After Combination Treatment With Xiaoshuan Enteric-Coated Capsule and Enriched Environment in Rats After Stroke. Front Neurosci 2019; 13:701. [PMID: 31354412 PMCID: PMC6630081 DOI: 10.3389/fnins.2019.00701] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 06/20/2019] [Indexed: 12/13/2022] Open
Abstract
Xiaoshuan enteric-coated capsule (XSEC) is a Chinese medicinal compound widely used for treatment of ischemic cerebrovascular diseases. Enriched environment (EE) is an effective rehabilitative protocol designed to enhance sensorimotor, cognitive and social stimulation. This study aimed to apply magnetic resonance imaging (MRI) to non-invasively assess whether EE could augment the therapeutic benefits of XSEC on post-ischemic neurovascular remodeling. Male Sprague–Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO) and treated with XSEC and EE alone or combination for 30 consecutive days. Beam walking test and Morris water maze (MWM) test were performed to evaluate motor and cognitive function, respectively. Multimodal MRI was applied to examine alterations to brain structures, intracranial vessels, and cerebral perfusion on the 31st day after MCAO. Double-immunofluorescent staining was used to evaluate neurogenesis and angiogenesis. Western blot and RT-PCR were used to detect the expressions of vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), and the axon guidance molecules. Combination therapy with XSEC and EE significantly reduced cystic volume compared with XSEC and EE monotherapies. In line with this, combination treated rats performed better in the beam walking test and exhibited improved spatial memory in the probe trial of the MWM. Moreover, XSEC and EE combination treatment improved cerebral blood flow (CBF), amplified angiogenesis and upregulated VEGF protein levels. This proangiogenic effect was consistent with the increased progenitor cell proliferation and neuronal differentiation in the peri-infarct cortex and striatum. Specifically, the combined therapy of XSEC and EE markedly increased the Netrin-1 and Robo-1 protein expression levels compared with vehicle group, while no difference was observed between XSEC or EE monotherapy and vehicle group. Together, these findings indicate that the combination of XSEC and EE benefits neurovascular reorganization. This correlates with restoration of CBF, promotion of neurogenesis and angiogenesis, and activation of the intrinsic axonal guidance molecules, thereby facilitating greater physical rehabilitation after ischemic stroke.
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Affiliation(s)
- Yu Zhan
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Man-Zhong Li
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Le Yang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Xue-Feng Feng
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Qiu-Xia Zhang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Nan Zhang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
| | - Yuan-Yuan Zhao
- Medical Imaging Laboratory of Core Facility Center, Capital Medical University, Beijing, China
| | - Hui Zhao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China.,Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing, China
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7
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Mahara A, Enmi JI, Hsu YI, Kobayashi N, Hirano Y, Iida H, Yamaoka T. Superfine Magnetic Resonance Imaging of the Cerebrovasculature Using Self-Assembled Branched Polyethylene Glycol-Gd Contrast Agent. Macromol Biosci 2018; 18:e1700391. [PMID: 29665311 DOI: 10.1002/mabi.201700391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/15/2018] [Indexed: 12/12/2022]
Abstract
Magnetic resonance angiography is an attractive method for the visualization of the cerebrovasculature, but small-sized vessels are hard to visualize with the current clinically approved agents. In this study, a polymeric contrast agent for the superfine imaging of the cerebrovasculature is presented. Eight-arm polyethylene glycol with a molecular weight of ≈17 000 Da conjugated with a Gd chelate and fluorescein (F-8-arm PEG-Gd) is used. The relaxivity rate is 9.3 × 10-3 m-1 s-1 , which is threefold higher than that of free Gd chelate. Light scattering analysis reveals that F-8-arm PEG-Gd is formed by self-assembly. When the F-8-arm PEG-Gd is intravenously injected, cerebrovasculature as small as 100 µm in diameter is clearly visualized. However, signals are not enhanced when Gd chelate and Gd chelate-conjugated 8-arm PEG are injected. Furthermore, small vasculature around infarct region in rat stroke model can be visualized. These results suggest that F-8-arm PEG-Gd enhances the MR imaging of cerebrovasculature.
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Affiliation(s)
- Atsushi Mahara
- Department of Biomedical Engineering, National Cerebral and Cardiovascular Center Research Institute, Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Jun-Ichiro Enmi
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Yu-I Hsu
- Department of Biomedical Engineering, National Cerebral and Cardiovascular Center Research Institute, Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Naoki Kobayashi
- Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamatecho, Suita, Osaka, 565-8680, Japan
| | - Yoshiaki Hirano
- Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamatecho, Suita, Osaka, 565-8680, Japan
| | - Hidehiro Iida
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Fujishiro-dai, Suita, Osaka, 565-8565, Japan
| | - Tetsuji Yamaoka
- Department of Biomedical Engineering, National Cerebral and Cardiovascular Center Research Institute, Fujishiro-dai, Suita, Osaka, 565-8565, Japan
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8
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Li M, Ouyang J, Zhang Y, Cheng BCY, Zhan Y, Yang L, Zou H, Zhao H. Effects of total saponins from Trillium tschonoskii rhizome on grey and white matter injury evaluated by quantitative multiparametric MRI in a rat model of ischemic stroke. JOURNAL OF ETHNOPHARMACOLOGY 2018; 215:199-209. [PMID: 29309860 DOI: 10.1016/j.jep.2018.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 12/30/2017] [Accepted: 01/04/2018] [Indexed: 06/07/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Trillium tschonoskii rhizome (TTR), a medicinal herb, has been traditionally used to treat traumatic brain injury and headache in China. Although the potential neuroprotective efficacy of TTR has gained increasing interest, the pharmacological mechanism remains unclear. Steroid saponins are the main bioactive components of the herb. AIM OF THE STUDY To investigate the protective and repair-promoting effects of the total saponins from TTR (TSTT) on grey and white matter damages in a rat model of middle cerebral artery occlusion (MCAO) using magnetic resonance imaging (MRI) assay. MATERIALS AND METHODS Ischemic stroke was induced by MCAO. TSTT and Ginaton (positive control) were administered orally to rats 6h after stroke and daily thereafter. After 15 days of treatment, the survival rate of each group was calculated. We then conducted neurological deficit scores and beam walking test to access the neurological function after ischemic stroke. Subsequently, T2-weighted imaging (T2WI) and T2 relaxometry mapping were performed to measure infarct volume and grey and white matter integrity, respectively. Moreover, diffusion tensor imaging (DTI) was carried out to evaluate the grey and white matter microstructural damage. Additionally, arterial spin labelling (ASL) - cerebral blood flow (CBF) and magnetic resonance angiography (MRA) images provided dynamic information about vascular hemodynamic dysfunction after ischemic stroke. Finally, haematoxylin and eosin (HE) staining was carried out to evaluate the stroke-induced pathological changes in the brain. RESULTS The survival rate and neurological behavioural outcomes (Bederson scores and beam walking tests) were markedly ameliorated by TSTT (65mg/kg) treatment within 15 days after ischemic stroke. Moreover, T2WI and T2 relaxometry mapping showed that TSTT (65mg/kg) significantly reduced infarct volume and attenuated grey and white matter injury, respectively, which was confirmed by histopathological evaluation of brain tissue. The results obtained from DTI showed that TSTT (65mg/kg) not only significantly alleviated axonal damage and demyelination, but also promoted axonal remodelling and re-myelination. In addition, TSTT treatment also enhanced vascular signal density and increased CBF in rats after MCAO. CONCLUSION Our results suggested the potential protective and repair-promoting effects of TSTT on grey and white matter from damage induced by ischemia. This study provides a modern pharmacological basis for the application of TSTT in managing ischemic stroke.
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Affiliation(s)
- Manzhong Li
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China; Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing 100069, China
| | - Junyao Ouyang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China; Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing 100069, China
| | - Yi Zhang
- Department of pharmacology, Beijing University of Chinese Medicine, Beijing 100102, China
| | - Brian Chi Yan Cheng
- College of Professional and Continuing Education, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Yu Zhan
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China; Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing 100069, China
| | - Le Yang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China; Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing 100069, China
| | - Haiyan Zou
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China; Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing 100069, China.
| | - Hui Zhao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China; Beijing Key Lab of TCM Collateral Disease Theory Research, Beijing 100069, China.
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A general protocol of ultra-high resolution MR angiography to image the cerebro-vasculature in 6 different rats strains at high field. J Neurosci Methods 2017; 289:75-84. [PMID: 28694213 DOI: 10.1016/j.jneumeth.2017.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 07/06/2017] [Accepted: 07/06/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND Differences in the cerebro-vasculature among strains as well as individual animals might explain variability in animal models and thus, a non-invasive method tailored to image cerebral vessel of interest with high signal to noise ratio is required. NEW METHOD Experimentally, we describe a new general protocol of three-dimensional time-of-flight magnetic resonance angiography to visualize non-invasively the cerebral vasculature in 6 different rat strains. Flow compensated angiograms of Sprague Dawley, Wistar Kyoto, Lister Hooded, Long Evans, Fisher 344 and Spontaneous Hypertensive Rat strains were obtained without the use of contrast agents. At 11.7T using a repetition time of 60ms, an isotropic resolution of up to 62μm was achieved; total imaging time was 98min for a 3D data set. RESULTS The visualization of the cerebral arteries was improved by removing extra-cranial vessels prior to the calculation of maximum intensity projection to obtain the angiograms. Ultimately, we demonstrate that the newly implemented method is also suitable to obtain angiograms following middle cerebral artery occlusion, despite the presence of intense vasogenic edema 24h after reperfusion. COMPARISON WITH EXISTING METHODS The careful selection of the excitation profile and repetition time at a higher static magnetic field allowed an increase in spatial resolution to reliably detect of the hypothalamic artery, the anterior choroidal artery as well as arterial branches of the peri-amygdoidal complex and the optical nerve in six different rat strains. CONCLUSIONS MR angiography without contrast agent can be utilized to study cerebro-vascular abnormalities in various animal models.
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10
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Zhang J, Zou H, Zhang Q, Wang L, Lei J, Wang Y, Ouyang J, Zhang Y, Zhao H. Effects of Xiaoshuan enteric-coated capsule on neurovascular functions assessed by quantitative multiparametric MRI in a rat model of permanent cerebral ischemia. Altern Ther Health Med 2016; 16:198. [PMID: 27391841 PMCID: PMC4938911 DOI: 10.1186/s12906-016-1184-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/14/2016] [Indexed: 02/06/2023]
Abstract
Background Buyang Huanwu Decoction (BYHWD) is a Traditional Chinese Medicine (TCM) formula for treating stroke-induced disability. Xiaoshuan enteric-coated capsule (XSECC), derived from the formula BYHWD, is a drug approved by the China Food and Drug Administration (CFDA) for stroke management. To further investigate the potential protective effects of XSECC on neurovascular functions, we endeavour to monitor the neurovascular functions using multimodal magnetic resonance imaging (MRI) and evaluated histopathological changes of neurovascular unit (NVU) after stroke. Methods Ischemic stroke was induced by permanent middle cerebral artery occlusion (pMCAO). XSECC (420 mg/kg) was orally administered 2 h after stroke and daily thereafter. T2-weighted imaging (T2WI), T2 relaxometry mapping and diffusion tensor imaging (DTI) were used to measure cerebral infarct volume, edema and white matter fiber integrity, respectively. Neurochemical metabolite levels were monitored by 1H-magnetic resonance spectroscopy (1H-MRS). Arterial spin labeling (ASL) – cerebral blood flow (CBF) measurements and structural magnetic resonance angiography (MRA) images provided real-time and dynamic information about vascular hemodynamic dysfunction on the 3rd, 7th and 14th days after pMCAO. At the last imaging time point, immunohistochemistry, immunofluorescence as well as transmission electron microscopy (TEM) were used to test the microscopic and ultrastructural changes of NVU. Results T2WI, T2 relaxometry mapping and Fractional anisotropy (FA) in DTI showed that XSECC significantly reduced cerebral infarct volume, relieved edema and alleviated nerve fiber injuries, respectively. 1H-MRS provided information about improvement of neuronal/glial metabolism after XSECC treatment. Moreover, ASL – CBF measurements combined with MRA showed that XSECC significantly increased CBF and vascular signal strength and alleviated ischemia-induced morphological changes of arteries in ischemic hemisphere within 14 days after stroke. In addition, neuron specific nuclear protein (NeuN), glial fibrillary acidic protein (GFAP), CD34 staining and TEM detection indicated that XSECC not only ameliorated neuronal injury, but also reduced endothelial damage and inhibited astrocyte proliferation. Conclusions Our results suggested that XSECC has multi-target neurovascular protective effects on ischemic stroke, which may be closely correlated with the improvement of cerebral blood supply and neuronal/glial metabolism.
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11
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Chronic cerebral hypoperfusion induces vascular plasticity and hemodynamics but also neuronal degeneration and cognitive impairment. J Cereb Blood Flow Metab 2015; 35:1249-59. [PMID: 25853908 PMCID: PMC4528009 DOI: 10.1038/jcbfm.2015.55] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 02/19/2015] [Accepted: 03/10/2015] [Indexed: 12/16/2022]
Abstract
Chronic cerebral hypoperfusion (CCH) induces cognitive impairment, but the compensative mechanism of cerebral blood flow (CBF) is not fully understood. The present study mainly investigated dynamic changes in CBF, angiogenesis, and cellular pathology in the cortex, the striatum, and the cerebellum, and also studied cognitive impairment of rats induced by bilateral common carotid artery occlusion (BCCAO). Magnetic resonance imaging (MRI) techniques, immunochemistry, and Morris water maze were employed to the study. The CBF of the cortex, striatum, and cerebellum dramatically decreased after right common carotid artery occlusion (RCCAO), and remained lower level at 2 weeks after BCCAO. It returned to the sham level from 3 to 6 weeks companied by the dilation of vertebral arteries after BCCAO. The number of microvessels declined at 2, 3, and 4 weeks but increased at 6 weeks after BCCAO. Neuronal degeneration occurred in the cortex and striatum from 2 to 6 weeks, but the number of glial cells dramatically increased at 4 weeks after BCCAO. Cognitive impairment of ischemic rats was directly related to ischemic duration. Our results suggest that CCH induces a compensative mechanism attempting to maintain optimal CBF to the brain. However, this limited compensation cannot prevent neuronal loss and cognitive impairment after permanent ischemia.
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12
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Krucker T, Schuler A, Meyer EP, Staufenbiel M, Beckmann N. Magnetic resonance angiography and vascular corrosion casting as tools in biomedical research: application to transgenic mice modeling Alzheimer's disease. Neurol Res 2013; 26:507-16. [PMID: 15265268 DOI: 10.1179/016164104225016281] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
In vivo imaging technologies are presently receiving considerable attention in the biomedical and pharmaceutical research areas. One of the principal imaging modalities is magnetic resonance imaging (MRI). The multiparametric nature of MRI enables anatomical, functional and even molecular information to be obtained non-invasively from intact organisms at high spatial resolution. Here we describe the use of one MRI modality, namely angiography (MRA), to non-invasively study the arterial vascular architecture of APP23 transgenic mice modeling Alzheimer's disease. Because the spatial resolution of the technique is limited, the in vivo studies are complemented by a powerful analysis of the vasculature using vascular corrosion casting. Both techniques revealed age-dependent blood flow alterations and cerebrovascular abnormalities in these mice. Our experience suggests that MRA complemented by cast analysis are important tools to describe vascular alterations and test new therapy concepts in animal models of AD. Furthermore, being non-invasive, MRA can also be applied to studies in patients suffering from this disease.
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Affiliation(s)
- Thomas Krucker
- Department of Neuropharmacology, Scripps Research Institute, La Jolla, CA, USA
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13
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Cai K, Shore A, Singh A, Haris M, Hiraki T, Waghray P, Reddy D, Greenberg JH, Reddy R. Blood oxygen level dependent angiography (BOLDangio) and its potential applications in cancer research. NMR IN BIOMEDICINE 2012; 25:1125-1132. [PMID: 22302557 PMCID: PMC3390450 DOI: 10.1002/nbm.2780] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 12/06/2011] [Accepted: 12/21/2011] [Indexed: 05/31/2023]
Abstract
Clinically, development of anti-angiogenic drugs for cancer therapy is pivotal. Longitudinal monitoring of tumour angiogenesis can help clinicians determine the effectiveness of anti-angiogenic therapy. Blood oxygen level dependent (BOLD) effect has been widely used for functional imaging and tumour oxygenation assessment. In this study, the BOLD effect is investigated under different levels of oxygen inhalation for the development of a novel angiographic MRI technique, blood oxygen level dependent angiography (BOLDangio). Under short-term (<10 min) generalized hypoxia induced by inhalation of 8% oxygen, we measure BOLD contrast as high as 25% from vessels at 9.4T using a simple gradient echo (GRE) pulse sequence. This produces high-resolution 2D and 3D maps of normal and tumour brain vasculature in less than 10 minutes. Additionally, this technique reliably detects metastatic tumours and tumour-induced intracranial hemorrhage. BOLDangio provides a sensitive research tool for MRI of vasculature under normal and pathological conditions. Thus, it may be applied as a simple monitoring technique for measuring the effectiveness of anti-angiogenic drugs in a preclinical environment.
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Affiliation(s)
- Kejia Cai
- Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
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14
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Ke Z, Ying M, Li L, Zhang S, Tong KY. Evaluation of transcranial Doppler flow velocity changes in intracerebral hemorrhage rats using ultrasonography. J Neurosci Methods 2012; 210:272-80. [PMID: 22967488 DOI: 10.1016/j.jneumeth.2012.07.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 07/12/2012] [Accepted: 07/30/2012] [Indexed: 11/28/2022]
Abstract
This study investigated the blood flow velocity changes in seven major arteries in rat brain before and after intracerebral hemorrhage (ICH) using high frequency transcranial Doppler (TCD) ultrasonography (13-4 MHz). Eighteen adult Sprague Dawley rats received either the collagenase-injection surgery (ICH, n=12) or the saline-injection surgery (control, n=6) after baseline TCD flow velocity values were recorded. The TCD flow velocity changes were measured at 0.5h after the surgery and daily for the following 8 days in seven major cerebral arteries, including bilateral internal carotid arteries, bilateral middle cerebral arteries (MCAs), bilateral posterior cerebral arteries (PCAs), and basilar artery. The results showed a significant decrease of TCD flow velocity in the right MCA at 0.5 h and 24 h after the collagenase-injection surgery, and in the right PCA at 0.5 h in the ICH group rats. The TCD flow velocities in these two arteries gradually increased and then returned to the baseline values in the following days. The control group rats did not show significant changes in TCD flow velocity in all monitored arteries. This study demonstrates the feasibility and reliability of monitoring TCD flow velocity in cerebral arteries using ultrasonography technique in a rat ICH model. The results of this study extend our knowledge in the cerebrovascular changes during intracranial hemorrhage and suggest a possibility of clinical application of TCD ultrasonography in studying the dynamic cerebral circulation after strokes. Moreover, this method could be extensively applied in further studies using potential neuroprotective treatments that affect the cerebral dynamics in the intracerebral hemorrhage.
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Affiliation(s)
- Zheng Ke
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
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15
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Botnar RM, Makowski MR. Cardiovascular magnetic resonance imaging in small animals. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 105:227-61. [PMID: 22137434 DOI: 10.1016/b978-0-12-394596-9.00008-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Noninvasive imaging studies involving small animals are becoming increasingly important in preclinical pharmacological, genetic, and biomedical cardiovascular research. Especially small animal magnetic resonance imaging (MRI) using high field and clinical MRI systems has gained significant importance in recent years. Compared to other imaging modalities, like computer tomography, MRI can provide an excellent soft tissue contrast, which enables the characterization of different kinds of tissues without the use of contrast agents. In addition, imaging can be performed with high spatial and temporal resolution. Small animal MRI cannot only provide anatomical information about the beating murine heart; it can also provide functional and molecular information, which makes it a unique imaging modality. Compared to clinical MRI examinations in humans, small animal MRI is associated with additional challenges. These included a smaller size of all cardiovascular structures and a up to ten times higher heart rate. Dedicated small animal monitoring devices make a reliable cardiac triggering and respiratory gating feasible. MRI in combination with molecular probes enables the noninvasive imaging of biological processes at a molecular level. Different kinds of iron oxide or gadolinium-based contrast agents can be used for this purpose. Compared to other molecular imaging modalities, like single photon emission computed tomography (SPECT) and positron emission tomography (PET), MRI can also provide imaging with high spatial resolution, which is of high importance for the assessment of the cardiovascular system. The sensitivity for detection of MRI contrast agents is however lower compared to sensitivity of radiation associated techniques like PET and SPECT. This chapter is divided into the following sections: (1) "Introduction," (2) "Principals of Magnetic Resonance Imaging," (3) "MRI Systems for Preclinical Imaging and Experimental Setup," and (4) "Cardiovascular Magnetic Resonance Imaging."
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Affiliation(s)
- René M Botnar
- Division of Imaging Sciences, King's College London, London, United Kingdom
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16
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Wilson MH, Edsell MEG, Davagnanam I, Hirani SP, Martin DS, Levett DZH, Thornton JS, Golay X, Strycharczuk L, Newman SP, Montgomery HE, Grocott MPW, Imray CHE. Cerebral artery dilatation maintains cerebral oxygenation at extreme altitude and in acute hypoxia--an ultrasound and MRI study. J Cereb Blood Flow Metab 2011; 31:2019-29. [PMID: 21654697 PMCID: PMC3208157 DOI: 10.1038/jcbfm.2011.81] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Transcranial Doppler is a widely used noninvasive technique for assessing cerebral artery blood flow. All previous high altitude studies assessing cerebral blood flow (CBF) in the field that have used Doppler to measure arterial blood velocity have assumed vessel diameter to not alter. Here, we report two studies that demonstrate this is not the case. First, we report the highest recorded study of CBF (7,950 m on Everest) and demonstrate that above 5,300 m, middle cerebral artery (MCA) diameter increases (n=24 at 5,300 m, 14 at 6,400 m, and 5 at 7,950 m). Mean MCA diameter at sea level was 5.30 mm, at 5,300 m was 5.23 mm, at 6,400 m was 6.66 mm, and at 7,950 m was 9.34 mm (P<0.001 for change between 5,300 and 7,950 m). The dilatation at 7,950 m reversed with oxygen. Second, we confirm this dilatation by demonstrating the same effect (and correlating it with ultrasound) during hypoxia (FiO(2)=12% for 3 hours) in a 3-T magnetic resonance imaging study at sea level (n=7). From these results, we conclude that it cannot be assumed that cerebral artery diameter is constant, especially during alterations of inspired oxygen partial pressure, and that transcranial 2D ultrasound is a technique that can be used at the bedside or in the remote setting to assess MCA caliber.
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Affiliation(s)
- Mark H Wilson
- Centre for Altitude, Space and Extreme Environment Medicine, Institute of Human Health and Performance, Charterhouse Building, UCL Archway Campus, University College London, London, UK.
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17
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Kallur T, Hoehn M. Experimental stroke research: the contributions of in vivo MRI. Methods Mol Biol 2011; 771:255-275. [PMID: 21874483 DOI: 10.1007/978-1-61779-219-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Stroke is a disease that develops from the very acute time point of first symptoms during the next several hours and further to a chronic time period of days or even weeks. During this evolution process, a whole series of pathophysiological events takes place. Therefore, the disease is characterized by a continuously changing pathophysiological pattern. In consequence, as the disease develops over time, different imaging modalities must be chosen to accurately describe the status of stroke. In the present chapter, we have divided the evolution of stroke into various dominant steps of the cascade of events, with corresponding time windows. Choice of MRI variables for depiction of the most important aspects during these time windows are presented and their information content is discussed for diagnosis and for investigations into a better understanding of the underlying mechanisms for the disease as well as the relevance of these imaging tools in success assessments for therapeutic strategies.
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Affiliation(s)
- Therése Kallur
- In-vivo-NMR-Laboratory, Max Planck Institute for Neurological Research, D-50931 Köln, Germany.
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18
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Li L, Ke Z, Tong KY, Ying M. Evaluation of cerebral blood flow changes in focal cerebral ischemia rats by using transcranial Doppler ultrasonography. ULTRASOUND IN MEDICINE & BIOLOGY 2010; 36:595-603. [PMID: 20350686 DOI: 10.1016/j.ultrasmedbio.2010.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 12/31/2009] [Accepted: 01/15/2010] [Indexed: 05/17/2023]
Abstract
Ischemic stroke is typically characterized by the disruption of cerebral blood flow. This study aimed to consecutively evaluate the cerebral blood flow changes in a focal ischemia rat model during the occlusion-reperfusion procedure and along the recovery stage after stroke. In 12 Sprague Dawley (SD) rats, a middle cerebral artery occlusion/reperfusion (MCAo/r) surgery was conducted, which combines a permanent occlusion of the right common carotid artery (CCA), external carotid artery (ECA) and a transient occlusion of the right internal carotid artery (ICA) and middle cerebral artery (MCA) with a monofilament introduced from the proximal ICA towards the distal right ICA then removed after 90 min. Blood flow velocity (BFV) from the concerned arteries were measured using ultrasonography (13-4 MHz) at the basal stage before the surgery, after the reperfusion stage and during the post-stroke status. At reperfusion stage and after, BFV increased significantly in the left ICA and in the basilar artery (BA) (starting from post-24 h, p < 0.05 vs. basal). Moreover, BFV were reversed in the distal right ICA and reflow was recorded in the right MCA. Time-average maximum BFV in the right MCA at reperfusion and post-stroke 24-96 h was decreased significantly (p < 0.05 vs. basal). The reversed flow in the right ICA was enabled by the settlement of the collateral supply through the circle of Willis which consisted in higher BFV in the opposite ICA and in the BA still 24 h, although the proximal right ICA remain occluded. Ultrasound measurement of BFV helps to provide information on the redistribution of the blood flow supply after the onset of stroke.
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Affiliation(s)
- Le Li
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR, China
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19
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Makowski MR, Wiethoff AJ, Jansen CHP, Botnar RM. Cardiovascular MRI in small animals. Expert Rev Cardiovasc Ther 2010; 8:35-47. [PMID: 20014933 DOI: 10.1586/erc.09.126] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Imaging studies of cardiovascular disease in small rodents have become a prerequisite in preclinical cardiovascular research. Transgenic and gene-knockout models of cardiovascular diseases enables the investigation of the influence of single genes or groups of genes on disease pathogenesis. In addition, experimental and genetically altered models provide valuable in vivo platforms to investigate the efficacy of novel drugs and contrast agents. Owing to the excellent soft tissue contrast, high spatial and temporal resolution, as well as the tomographic nature of MRI, anatomy and function can be assessed with unique accuracy and reproducibility. Furthermore, using novel targeted MRI contrast agents, molecular changes associated with cardiovascular disease can be investigated in the same imaging session. This review focuses on recent advances in hardware, imaging sequences and probe design.
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Affiliation(s)
- Marcus R Makowski
- Division of Imaging Sciences, King's College London, 4th Floor, Lambeth Wing, St Thomas' Hospital, London SE1 7EH, UK.
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20
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Lin CY, Lin MH, Cheung WM, Lin TN, Chen JH, Chang C. In vivo cerebromicrovasculatural visualization using 3D ΔR2-based microscopy of magnetic resonance angiography (3DΔR2-mMRA). Neuroimage 2009; 45:824-31. [DOI: 10.1016/j.neuroimage.2008.12.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/13/2008] [Accepted: 12/08/2008] [Indexed: 11/16/2022] Open
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21
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Use of a clinical MRI scanner for preclinical research on rats. Radiol Phys Technol 2009; 2:13-21. [DOI: 10.1007/s12194-008-0038-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 08/22/2008] [Accepted: 08/27/2008] [Indexed: 10/21/2022]
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22
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Yang YM, Feng X, Yao ZW, Tang WJ, Liu HQ, Zhang L. Magnetic resonance angiography of carotid and cerebral arterial occlusion in rats using a clinical scanner. J Neurosci Methods 2007; 167:176-83. [PMID: 17889370 DOI: 10.1016/j.jneumeth.2007.08.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 08/02/2007] [Accepted: 08/07/2007] [Indexed: 11/30/2022]
Abstract
In rat models to induce both focal cerebral ischemia and chronic cerebral hypoperfusion, it is highly desirable to verify the success of vessel occlusion and reopening with non-invasive method. The contrast-agent free 3D time-of-flight magnetic resonance angiography (TOF-MRA), diffusion-weighted imaging (DWI) and T2-weighted imaging by 3.0-T MR clinical scanner were applied when unilateral middle cerebral artery (MCA) was occluded and reopened, and after bilateral common carotid arteries were in ligation. The arterial angiograms of the rat brain and neck were achieved successfully in all chosen directions by the 3D TOF-MRA. It was shown that MCA in occlusion presented no signal in MRA, and the parenchyma of the ipsilateral MCA territory hypointensity signal in maps of apparent diffusion coefficient (ADC). After reperfusion, the signal intensity of ipsilateral MCA was resumed in MRA, and the decreased ADC was restored simultaneously. However, after 5h of reperfusion, it was found that the value of ADC deteriorated second time with high T2 value. In bilateral common carotid artery occlusion (BCCAO) rats, it can be confirmed by MRA that the effectively occluded BCCA presented the absent signal and the basilar artery became tortuous. As a result, MRA by clinical scanner was proved of a valuable method to validate transient middle cerebral artery occlusion (MCAO) and permanent BCCAO rat model.
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Affiliation(s)
- Yan Mei Yang
- Department of Radiology, HuaShan Hospital of FuDan University, 12 Wulumuqi Zhong Road, ShangHai 200040, China
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23
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Bolan PJ, Yacoub E, Garwood M, Ugurbil K, Harel N. In vivo micro-MRI of intracortical neurovasculature. Neuroimage 2006; 32:62-9. [PMID: 16675271 DOI: 10.1016/j.neuroimage.2006.03.027] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Revised: 03/08/2006] [Accepted: 03/14/2006] [Indexed: 11/20/2022] Open
Abstract
This work describes a methodology for in vivo MR imaging of arteries and veins within the visual cortex of the cat brain. Very high magnetic fields (9.4 T) and small field-of-view 3D acquisitions were used to image the neurovasculature at resolutions approaching the microscopic scale. A combination of time-of-flight MR angiography and T*(2)-weighted imaging, using both endogenous BOLD contrast and an exogenous iron-oxide contrast agent, provided high specificity for distinguishing between arteries and veins within the cortex. These acquisition techniques, combined with 3D image processing and display methods, were used to detect and visualize intracortical arteries and veins with diameters smaller than 100 microm. This methodology can be used for visualizing the neurovasculature or building models of the vascular network and may benefit a variety of research applications including fMRI, cerebrovascular disease and cancer angiogenesis.
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Affiliation(s)
- Patrick J Bolan
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota School of Medicine, 2021 Sixth Street SE, Minneapolis, MN 55455, USA.
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Choy M, Ganesan V, Thomas DL, Thornton JS, Proctor E, King MD, van der Weerd L, Gadian DG, Lythgoe MF. The chronic vascular and haemodynamic response after permanent bilateral common carotid occlusion in newborn and adult rats. J Cereb Blood Flow Metab 2006; 26:1066-75. [PMID: 16395291 DOI: 10.1038/sj.jcbfm.9600259] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vascular growth and redistribution of flow can compensate for arterial occlusion and possibly reduce the effects of hypoperfusion. As yet there is limited information on the age-dependent nature of vasculature remodelling. In this study, we have monitored the vascular and morphologic changes using magnetic resonance imaging and histology in a chronic bilateral common carotid artery occlusion (BCCAO) model in both newborn and adult rats. Acutely, cerebral blood flow (CBF) decreased immediately after BCCAO, producing a state of oligemic hypoperfusion. At 6 months after BCCAO in both adult and neonatal rats, the CBF had normalised at control values. To investigate the underlying mechanism for the return of CBF to control values, intra- and extracerebral magnetic resonance angiograms (MRAs) were acquired. As expected, signal from the common carotid arteries was present in the sham-operated rats, but was absent in the BCCAO animals. India ink angiograms demonstrated more tortuous basilar arteries in the adult rats post-BCCAO and MRAs demonstrated more extracerebral midline collaterals in the neonatal rats post-BCCAO, indicating different modes of vascular adaptation dependent on the age at onset of the insult. Both groups had collateral vessels arising from the vertebral arteries, and BCCAO was also associated with increased diameter of basilar, posterior cerebral, posterior communicating, internal carotid, middle cerebral and anterior cerebral arteries. Our study suggests that the developing and mature animals exhibit different patterns of vascular remodelling and that the BCCAO hypoperfusion model will be useful for investigating age-dependent vascular events in response to vaso-occlusive disease.
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Affiliation(s)
- Mankin Choy
- RCS Unit of Biophysics, Institute of Child Health, University College London, London, UK
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25
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Weber R, Ramos-Cabrer P, Hoehn M. Present status of magnetic resonance imaging and spectroscopy in animal stroke models. J Cereb Blood Flow Metab 2006; 26:591-604. [PMID: 16292254 DOI: 10.1038/sj.jcbfm.9600241] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Magnetic resonance imaging (MRI) is based on a wide variety of physical parameters, which, in principle, can all influence the image contrast conditions. As these diverse variables are validated by independent physiological, metabolic, hemodynamic, and histological techniques, a physiological MRI evolves. This imaging modality has been successfully applied to experimental stroke studies, covering a broad range of raised questions. In the present review, we present an overview of possible physiological criteria to be studied by in vivo MRI and magnetic resonance spectroscopy, and critically analyze the present limits and future potential of the imaging technique for experimental stroke investigations. The documented applications cover the spectrum from morphological-structural details of the lesion to hemodynamic and metabolic alterations, inflammatory reaction, evaluation of thrombolytic treatment, studies on recovery of functional brain activation by functional MRI, and, finally, the most recent applications of exploring stem cells for regenerative therapy.
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Affiliation(s)
- Ralph Weber
- In-vivo-NMR-Laboratory, Max-Planck-Institute for Neurological Research, Cologne, Germany
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26
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Fehm NP, Vatankhah B, Dittmar MS, Retzl G, Schuierer G, Horn M, Schlachetzki F. Application of Clinical Scanners in Rats: Experimental Carotid Imaging Using Magnetic Resonance Imaging, Spiral Computed Tomography, and Color Duplex Ultrasound. J Neuroimaging 2005. [DOI: 10.1111/j.1552-6569.2005.tb00330.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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27
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Chen F, Suzuki Y, Nagai N, Peeters R, Coenegrachts K, Coudyzer W, Marchal G, Ni Y. Visualization of stroke with clinical MR imagers in rats: a feasibility study. Radiology 2004; 233:905-11. [PMID: 15498899 DOI: 10.1148/radiol.2333031658] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This experiment was conducted in compliance with the guidelines of the International Committee on Thrombosis and Hemostasis and the current institutional regulations for use and care of laboratory animals. The purpose of the present study was to report the feasibility of using clinical magnetic resonance (MR) imaging devices for depiction of stroke in a rat model. Twenty-four rats with photochemically induced thrombosis of the middle cerebral artery were examined at superacute (1 hour, n = 24), acute (12 hours, n = 12), and subacute (24 hours, n = 12) phases with 1.5-T MR imaging weighted for T1, T2, diffusion, and gadopentetate dimeglumine-enhanced perfusion. With reasonable signal-to-noise ratio and imaging times, ischemic lesions were well distinguished on MR images as validated qualitatively and quantitatively with postmortem standard-of-reference techniques, including volume-rendered computed tomography, microangiography, and histochemistry. In the superacute phase, the perfusion defect at perfusion-weighted MR imaging was well matched with microangiographic and pathologic findings (P > .05). There was no difference in lesion size at perfusion-weighted MR imaging between superacute and subacute phases (P > .05). Performance of certain stroke-related research in rats is feasible with clinical MR imagers.
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Affiliation(s)
- Feng Chen
- Department of Radiology, University Hospitals, K. U. Leuven, Herestraat 49, B-3000 Leuven, Belgium
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28
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Gerriets T, Stolz E, Walberer M, Müller C, Rottger C, Kluge A, Kaps M, Fisher M, Bachmann G. Complications and pitfalls in rat stroke models for middle cerebral artery occlusion: a comparison between the suture and the macrosphere model using magnetic resonance angiography. Stroke 2004; 35:2372-7. [PMID: 15345802 DOI: 10.1161/01.str.0000142134.37512.a7] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Investigating focal cerebral ischemia requires animal models that are relevant to human stroke. Complications and side effects are common among these models. The present study describes potential pitfalls in 3 techniques for middle cerebral artery occlusion (MCAO) in rats using magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA). METHODS Rats were subjected to temporary MCAO for 90 minutes using the suture technique (group I; n=10) or to permanent MCAO using the suture technique (group II; n=10) or the macrosphere technique (group III; n=10). Clinical evaluation was performed after 3 hours and 24 hours. After 24 hours, animals underwent MRI and MRA to determine lesion size and the intracranial vascular status. RESULTS Hemispheric lesion volume was significantly smaller in group I (14.6%) compared with groups II (35.2%; P<0.01) and III (21.3%; P<0.05). Two animals (1 each in group II and III) did not demonstrate neurological deficits and had no lesion on MRI and a patent MCA main stem on MRA. Subarachnoid hemorrhage was detected in 2 animals (1 each in group I and II). MRA indicated a patent MCA main stem in 2 animals (group II), although both rats displayed neurological deficits. Hypothalamic infarction with subsequent pathological hyperthermia was detected in all animals in group II and in 1 rat in group III. CONCLUSIONS Model failures occurred frequently in all groups. MRI and MRA helps to identify animals that need to be excluded from experimental stroke studies.
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Affiliation(s)
- Tibo Gerriets
- Department of Radiology, Experimental Neurology Research Group, Kerckhoff-Klinik Bad Nauheim, Germany
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29
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Hilger T, Niessen F, Diedenhofen M, Hossmann KA, Hoehn M. Magnetic resonance angiography of thromboembolic stroke in rats: indicator of recanalization probability and tissue survival after recombinant tissue plasminogen activator treatment. J Cereb Blood Flow Metab 2002; 22:652-62. [PMID: 12045663 DOI: 10.1097/00004647-200206000-00003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Magnetic resonance angiography (MRA) was performed in a thromboembolic stroke model of the rat to characterize intracranial vessel occlusion patterns and to test its predictive power for tissue recovery after recombinant tissue plasminogen activator (rt-PA) treatment. After rt-PA-treated selective middle cerebral artery (MCA) occlusion, full recanalization was observed in two of three animals, whereas additional occlusion of the circle of Willis (CW) resulted in full vascular flow restitution in only one of six rats. Tissue reperfusion markedly lagged the onset of treatment, and the delay correlated with the pattern of vessel occlusion (20 to 23 minutes for selective MCA occlusion vs. 71 to 79 minutes for combined MCA/CW occlusion). In lateral cortex and striatum the apparent diffusion coefficient decreased to 78 +/- 15% of control after embolization, recovered to 80% to 85% after rt-PA treatment of selective MCA occlusion, but further declined to 66% to 69% after combined MCA/CW occlusion. Correspondingly, T2 relaxation time increased to 107% to 118% of control after selective MCA occlusion and to 112% to 124% after combined MCA/CW occlusion in these regions. The present investigation shows that MRA provides valuable information on the severity of thromboembolic stroke and has the power to predict, before the initiation of treatment, the functional tissue outcome after rt-PA-induced thrombolysis.
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Affiliation(s)
- Thomas Hilger
- Department of Experimental Neurology, Max-Planck-Institute for Neurological Research, Köln, Germany.
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