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Tessier A, Ruze AJ, Varlet I, Laïb EMH, Royer E, Bernard M, Viola A, Perles-Barbacaru TA. Quantitative MRI of Gd-DOTA Accumulation in the Mouse Brain After Intraperitoneal Administration: Validation by Mass Spectrometry. J Magn Reson Imaging 2024; 60:316-324. [PMID: 37811700 DOI: 10.1002/jmri.29034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/19/2023] [Accepted: 09/19/2023] [Indexed: 10/10/2023] Open
Abstract
BACKGROUND In mice, intraperitoneal (ip) contrast agent (CA) administration is convenient for mapping microvascular parameters over a long-time window. However, continuous quantitative MRI of CA accumulation in brain over hours is still missing. PURPOSE To validate a quantitative time-resolved MRI technique for mapping the CA kinetics in brain upon ip administration. STUDY TYPE Prospective, animal model. SPECIMEN 25 C57Bl/6JRj mice underwent MRI. FIELD STRENGTH/SEQUENCE 7-T, gradient echo sequence. ASSESSMENT Gd-DOTA concentration was monitored by MRI (25 s/repetition) over 135 minutes with (N = 15) and without (N = 10) ip mannitol challenge (5 g/kg). After the final repetition, the brains were sampled to quantify gadolinium by mass spectrometry (MS). Upon manual brain segmentation, the average gadolinium concentration was compared with the MS quantification in transcardially perfused (N = 20) and unperfused (N = 5) mice. Precontrast T1-maps were acquired in 8 of 25 mice. STATISTICAL TESTS One-tailed Spearman and Pearson correlation between gadolinium quantification by MRI and by MS, D'Agostino-Pearson test for normal distribution, Bland-Altman analysis to evaluate the agreement between MRI and MS. Significance was set at P-value <0.05. RESULTS MRI showed that ip administered CA reached the blood compartment (>5 mM) within 10 minutes and accumulated continuously for 2 hours in cerebrospinal fluid (>1 mM) and in brain tissue. The MRI-derived concentration maps showed interindividual differences in CA accumulation (from 0.47 to 0.81 mM at 2 hours) with a consistent distribution resembling the pathways of the glymphatic system. The average in-vivo brain concentration 2 hours post-CA administration correlated significantly (r = 0.8206) with the brain gadolinium quantification by MS for N = 21 paired observations available. DATA CONCLUSION The presented experimental and imaging protocol may be convenient for monitoring the spatiotemporal pattern of CA uptake and clearance in the mouse brain over 2 hours. The quantification of the CA from the MRI signal in brain is corroborated by MS. EVIDENCE LEVEL N/A TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Anthony Tessier
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
- Department of Medical Imaging, Sainte-Anne Military Teaching Hospital (Hôpital d'Instruction des Armées), Toulon, France
| | - Anthony J Ruze
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
| | - Isabelle Varlet
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
| | - Estelle M H Laïb
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
| | - Emilien Royer
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
| | - Monique Bernard
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
| | - Angèle Viola
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
| | - Teodora-Adriana Perles-Barbacaru
- CNRS, Center for Magnetic Resonance Imaging in Biology and Medicine (CRMBM, UMR CNRS 7339), Aix-Marseille University, Marseille, France
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Fernández-Rodicio S, Ferro-Costas G, Sampedro-Viana A, Bazarra-Barreiros M, Ferreirós A, López-Arias E, Pérez-Mato M, Ouro A, Pumar JM, Mosqueira AJ, Alonso-Alonso ML, Castillo J, Hervella P, Iglesias-Rey R. Perfusion-weighted software written in Python for DSC-MRI analysis. Front Neuroinform 2023; 17:1202156. [PMID: 37593674 PMCID: PMC10431979 DOI: 10.3389/fninf.2023.1202156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/27/2023] [Indexed: 08/19/2023] Open
Abstract
Introduction Dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion studies in magnetic resonance imaging (MRI) provide valuable data for studying vascular cerebral pathophysiology in different rodent models of brain diseases (stroke, tumor grading, and neurodegenerative models). The extraction of these hemodynamic parameters via DSC-MRI is based on tracer kinetic modeling, which can be solved using deconvolution-based methods, among others. Most of the post-processing software used in preclinical studies is home-built and custom-designed. Its use being, in most cases, limited to the institution responsible for the development. In this study, we designed a tool that performs the hemodynamic quantification process quickly and in a reliable way for research purposes. Methods The DSC-MRI quantification tool, developed as a Python project, performs the basic mathematical steps to generate the parametric maps: cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), signal recovery (SR), and percentage signal recovery (PSR). For the validation process, a data set composed of MRI rat brain scans was evaluated: i) healthy animals, ii) temporal blood-brain barrier (BBB) dysfunction, iii) cerebral chronic hypoperfusion (CCH), iv) ischemic stroke, and v) glioblastoma multiforme (GBM) models. The resulting perfusion parameters were then compared with data retrieved from the literature. Results A total of 30 animals were evaluated with our DSC-MRI quantification tool. In all the models, the hemodynamic parameters reported from the literature are reproduced and they are in the same range as our results. The Bland-Altman plot used to describe the agreement between our perfusion quantitative analyses and literature data regarding healthy rats, stroke, and GBM models, determined that the agreement for CBV and MTT is higher than for CBF. Conclusion An open-source, Python-based DSC post-processing software package that performs key quantitative perfusion parameters has been developed. Regarding the different animal models used, the results obtained are consistent and in good agreement with the physiological patterns and values reported in the literature. Our development has been built in a modular framework to allow code customization or the addition of alternative algorithms not yet implemented.
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Affiliation(s)
- Sabela Fernández-Rodicio
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | | | - Ana Sampedro-Viana
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Marcos Bazarra-Barreiros
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | | | - Esteban López-Arias
- Translational Stroke Laboratory (TREAT), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - María Pérez-Mato
- Neurological Sciences and Cerebrovascular Research Laboratory, Department of Neurology and Stroke Center, La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Universidad Autónoma de Madrid, Madrid, Spain
| | - Alberto Ouro
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - José M. Pumar
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- Department of Neuroradiology, Hospital Clínico Universitario, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Antonio J. Mosqueira
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
- Department of Neuroradiology, Hospital Clínico Universitario, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - María Luz Alonso-Alonso
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - José Castillo
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Pablo Hervella
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
| | - Ramón Iglesias-Rey
- Neuroimaging and Biotechnology Laboratory (NOBEL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela, Spain
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Poulain A, Riseth J, Vinje V. Multi-compartmental model of glymphatic clearance of solutes in brain tissue. PLoS One 2023; 18:e0280501. [PMID: 36881576 PMCID: PMC9990927 DOI: 10.1371/journal.pone.0280501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/02/2023] [Indexed: 03/08/2023] Open
Abstract
The glymphatic system is the subject of numerous pieces of research in biology. Mathematical modelling plays a considerable role in this field since it can indicate the possible physical effects of this system and validate the biologists' hypotheses. The available mathematical models that describe the system at the scale of the brain (i.e. the macroscopic scale) are often solely based on the diffusion equation and do not consider the fine structures formed by the perivascular spaces. We therefore propose a mathematical model representing the time and space evolution of a mixture flowing through multiple compartments of the brain. We adopt a macroscopic point of view in which the compartments are all present at any point in space. The equations system is composed of two coupled equations for each compartment: One equation for the pressure of a fluid and one for the mass concentration of a solute. The fluid and solute can move from one compartment to another according to certain membrane conditions modelled by transfer functions. We propose to apply this new modelling framework to the clearance of 14C-inulin from the rat brain.
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Affiliation(s)
- Alexandre Poulain
- Laboratoire Paul Painlevé, UMR 8524 CNRS, Université de Lille, Lille, France
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
- * E-mail:
| | - Jørgen Riseth
- Department of Mathematics, University of Oslo, Oslo, Norway
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
| | - Vegard Vinje
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
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Gimenez U, Perles-Barbacaru AT, Millet A, Appaix F, El-Atifi M, Pernet-Gallay K, van der Sanden B, Berger F, Lahrech H. Microscopic DTI accurately identifies early glioma cell migration: correlation with multimodal imaging in a new glioma stem cell model. NMR IN BIOMEDICINE 2016; 29:1553-1562. [PMID: 27717043 DOI: 10.1002/nbm.3608] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 07/20/2016] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
Monitoring glioma cell infiltration in the brain is critical for diagnosis and therapy. Using a new glioma Glio6 mouse model derived from human stem cells we show how diffusion tensor imaging (DTI) may predict glioma cell migration/invasion. In vivo multiparametric MRI was performed at one, two and three months of Glio6 glioma growth (Glio6 (n = 6), sham (n = 3)). This longitudinal study reveals the existence of a time window to study glioma cell/migration/invasion selectively. Indeed, at two months only Glio6 cell invasion was detected, while tumor mass formation, edema, blood-brain barrier leakage and tumor angiogenesis were detected later, at three months. To robustly confirm the potential of DTI for detecting glioma cell migration/invasion, a microscopic 3D-DTI (80 μm isotropic spatial resolution) technique was developed and applied to fixed mouse brains (Glio6 (n = 6), sham (n = 3)). DTI changes were predominant in the corpus callosum (CC), a known path of cell migration. Fractional anisotropy (FA) and perpendicular diffusivity (D⊥ ) changes derived from ex vivo microscopic 3D-DTI were significant at two months of tumor growth. In the caudate putamen an FA increase of +38% (p < 0.001) was observed, while in the CC a - 28% decrease in FA (p < 0.005) and a + 95% increase in D⊥ (p < 0.005) were observed. In the CC, DTI changes and fluorescent Glio6 cell density obtained by two-photon microscopy in the same brains were correlated (p < 0.001, r = 0.69), validating FA and D⊥ as early quantitative biomarkers to detect glioma cell migration/invasion. The origin of DTI changes was assessed by electron microscopy of the same tract, showing axon bundle disorganization. During the first two months, Glio6 cells display a migratory phenotype without being associated with the constitution of a brain tumor mass. This offers a unique opportunity to apply microscopic 3D-DTI and to validate DTI parameters FA and D⊥ as biomarkers for glioma cell invasion.
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Affiliation(s)
| | | | | | - Florence Appaix
- Grenoble Institut des Neurosciences Inserm U836, Grenoble, France
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Perles-Barbacaru TA, Tropres I, Sarraf MG, Chechin D, Zaccaria A, Grand S, Le Bas JF, Berger F, Lahrech H. Technical Note: Clinical translation of the Rapid-Steady-State-T1 MRI method for direct cerebral blood volume quantification. Med Phys 2015; 42:6369-75. [PMID: 26520728 DOI: 10.1118/1.4932218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE In preclinical studies, the Rapid-Steady-State-T1 (RSST1) MRI method has advantages over conventional MRI methods for blood volume fraction (BVf) mapping, since after contrast agent administration, the BVf is directly quantifiable from the signal amplitude corresponding to the vascular equilibrium magnetization. This study focuses on its clinical implementation and feasibility. METHODS Following sequence implementation on clinical Philips Achieva scanners, the RSST1-method is assessed at 1.5 and 3 T in the follow-up examination of neurooncological patients receiving 0.1-0.2 mmol/kg Gd-DOTA to determine the threshold dose needed for cerebral BVf quantification. Confounding effects on BVf quantification such as transendothelial water exchange, transverse relaxation, and contrast agent extravasation are evaluated. RESULTS For a dose≥0.13 mmol/kg at 1.5 T and ≥0.16 mmol/kg at 3 T, the RSST1-signal time course in macrovessels and brain tissue with Gd-DOTA impermeable vasculature reaches a steady state at maximum amplitude for about 8 s. In macrovessels, a BVf of 100% was obtained validating cerebral microvascular BVf quantification (3.5%-4.5% in gray matter and 1.5%-2.0% in white matter). In tumor tissue, a continuously increasing signal is detected, necessitating signal modeling for tumor BVf calculation. CONCLUSIONS Using approved doses of Gd-DOTA, the steady state RSST1-signal in brain tissue is reached during the first pass and corresponds to the BVf. The first-pass duration is sufficient to allow accurate BVf quantification. The RSST1-method is appropriate for serial clinical studies since it allows fast and straightforward BVf quantification without arterial input function determination. This quantitative MRI method is particularly useful to assess the efficacy of antiangiogenic agents.
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Affiliation(s)
| | - Irene Tropres
- IRMaGe, Université Grenoble Alpes, Grenoble 38054, France; US 017 INSERM, Grenoble 38054, France; and UMS 3552, CNRS, Grenoble 38054, France
| | - Michel G Sarraf
- Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France
| | | | - Affif Zaccaria
- Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France
| | - Sylvie Grand
- Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble 38054, France
| | - Jean-François Le Bas
- Department of Neuroradiology and MRI, Grenoble University Hospital, Grenoble 38054, France
| | - François Berger
- Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France
| | - Hana Lahrech
- Clinatec INSERM UA01, Centre de Recherche Edmond J. Safra, CEA Grenoble, Grenoble 38054, France
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Sarraf M, Perles-Barbacaru AT, Nissou MF, van der Sanden B, Berger F, Lahrech H. Rapid-Steady-State-T1
signal modeling during contrast agent extravasation: Toward tumor blood volume quantification without requiring the arterial input function. Magn Reson Med 2014; 73:1005-14. [DOI: 10.1002/mrm.25218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 02/12/2014] [Accepted: 02/13/2014] [Indexed: 01/23/2023]
Affiliation(s)
- Michel Sarraf
- Université Joseph Fourier; Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale INSERM-U836, Bâtiment Edmond J. Safra, Chemin Fortuné Ferrini; Grenoble France
- CLINATEC; Commissariat à l'énergie atomique et aux énergies alternatives, MINATEC Campus; Grenoble France
- Université Saint Joseph-Faculté des sciences; Département de physique, campus des sciences et technologies, Mar Roukos; Mkallès Lebanon
| | - Adriana Teodora Perles-Barbacaru
- Université Joseph Fourier; Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale INSERM-U836, Bâtiment Edmond J. Safra, Chemin Fortuné Ferrini; Grenoble France
- CLINATEC; Commissariat à l'énergie atomique et aux énergies alternatives, MINATEC Campus; Grenoble France
- Aix Marseille Université; CRMBM UMR CNRS 7339; Marseille France
| | - Marie France Nissou
- Université Joseph Fourier; Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale INSERM-U836, Bâtiment Edmond J. Safra, Chemin Fortuné Ferrini; Grenoble France
- CLINATEC; Commissariat à l'énergie atomique et aux énergies alternatives, MINATEC Campus; Grenoble France
| | - Boudewijn van der Sanden
- Université Joseph Fourier; Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale INSERM-U836, Bâtiment Edmond J. Safra, Chemin Fortuné Ferrini; Grenoble France
- CLINATEC; Commissariat à l'énergie atomique et aux énergies alternatives, MINATEC Campus; Grenoble France
| | - François Berger
- Université Joseph Fourier; Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale INSERM-U836, Bâtiment Edmond J. Safra, Chemin Fortuné Ferrini; Grenoble France
- CLINATEC; Commissariat à l'énergie atomique et aux énergies alternatives, MINATEC Campus; Grenoble France
| | - Hana Lahrech
- Université Joseph Fourier; Grenoble Institut des Neurosciences, Institut National de la Santé et de la Recherche Médicale INSERM-U836, Bâtiment Edmond J. Safra, Chemin Fortuné Ferrini; Grenoble France
- CLINATEC; Commissariat à l'énergie atomique et aux énergies alternatives, MINATEC Campus; Grenoble France
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Perles-Barbacaru AT, Berger F, Lahrech H. Quantitative rapid steady state T1 magnetic resonance imaging for cerebral blood volume mapping in mice: Lengthened measurement time window with intraperitoneal Gd-DOTA injection. Magn Reson Med 2012; 69:1451-6. [PMID: 22760854 DOI: 10.1002/mrm.24365] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 04/20/2012] [Accepted: 05/13/2012] [Indexed: 11/09/2022]
Abstract
This work demonstrates how the rapid steady state T1 MRI technique for cerebral blood volume fraction (BVf) quantification can be used with intraperitoneal Gd-DOTA injections in mice at 4.7 T. The peak signal amplitude after intravenous administration (0.7 mmol/kg) and the steady state signal amplitude reached 15 min after intraperitoneal administration (6 mmol/kg) in the same mice lead to equivalent BVf measures in the order of 0.02 in the brain. The resulting time window for BVf quantification is ≈30 min and allows for cerebral BVf mapping with increased spatial resolution or signal-to-noise ratio, or for monitoring functional BVf changes. A cerebral BVf increase of up to 25% induced by the vasodilator acetazolamide was observed, validating the vascular origin of the signal. The noninvasive and quantitative rapid steady state T1 technique can be used in serial studies to evaluate new drugs or disease models, such as antiangiogenic therapies in tumors.
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How stereological analysis of vascular morphology can quantify the blood volume fraction as a marker for tumor vasculature: comparison with magnetic resonance imaging. J Cereb Blood Flow Metab 2012; 32:489-501. [PMID: 22068227 PMCID: PMC3293112 DOI: 10.1038/jcbfm.2011.151] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To assess angiogenesis noninvasively in a C6 rat brain tumor model, the rapid-steady-state-T(1) (RSST(1)) magnetic resonance imaging (MRI) method was used for microvascular blood volume fraction (BVf) quantification with a novel contrast agent gadolinium per (3,6 anhydro) α-cyclodextrin (Gd-ACX). In brain tissue contralateral to the tumor, equal BVfs were obtained with Gd-ACX and the clinically approved gadoterate meglumine (Gd-DOTA). Contrary to Gd-DOTA, which leaks out of the tumor vasculature, Gd-ACX was shown to remain vascular in the tumor tissue allowing quantification of the tumor BVf. We sought to confirm the obtained tumor BVf using an independent method: instead of using a 'standard' two-dimensional histologic method, we study here how vascular morphometry combined with a stereological technique can be used for three-dimensional assessment of the vascular volume fraction (V(V)). The V(V) is calculated from the vascular diameter and length density. First, the technique is evaluated on simulated data and the healthy rat brain vasculature and is then applied to the same C6 tumor vasculature previously quantified by RSST(1)-MRI with Gd-ACX. The mean perfused V(V) and the BVf obtained by MRI in tumor regions are practically equal and the technique confirms the spatial heterogeneity revealed by MRI.
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Abstract
Perfusion MRI is a tool to assess the spatial distribution of microvascular blood flow. Arterial spin labeling (ASL) is shown here to be advantageous for quantification of cerebral microvascular blood flow (CBF) in rodents. This technique is today ready for assessment of a variety of murine models of human pathology including those associated with diffuse microvascular dysfunction. This chapter provides an introduction to the principles of CBF measurements by MRI along with a short overview over applications in which these measurements were found useful. The basics of commonly employed specific arterial spin-labeling techniques are described and theory is outlined in order to give the reader the ability to set up adequate post-processing tools. Three typical MR protocols for pulsed ASL on two different MRI systems are described in detail along with all necessary sequence parameters and technical requirements. The importance of the different parameters entering theory is discussed. Particular steps for animal preparation and maintenance during the experiment are given, since CBF regulation is sensitive to a number of experimental physiological parameters and influenced mainly by anesthesia and body temperature.
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Abstract
To develop a less-stressful and simple method for measurement of the cerebral metabolic rate of oxygen (CMRO(2)) in small animals, the steady-state method was applied to injectable (15)O(2)-PET ((15)O(2)-positron emission tomography) using hemoglobin-containing vesicles ((15)O(2)-HbV). Ten normal rats and 10 with middle cerebral arterial occlusion (MCAO) were studied using a small animal PET scanner. A series of (15)O-PET scans with C(15)O-labeled HbV, H(2)(15)O, and (15)O(2)-HbV were performed with 10 to 15 minutes intervals to measure cerebral blood volume (CBV), cerebral blood flow (CBF), and CMRO(2). Positron emission tomography scans were started with a tracer injection using a multiprogramming syringe pump, which provides a slowly increasing injection volume to achieve steady-state radioactivity for H(2)(15)O and (15)O(2)-HbV scans. The radioactivity concentration of (15)O rapidly achieved equilibrium in the blood and whole brain at about 2 minutes after H(2)(15)O and (15)O(2)-HbV administration, which was stable during the scans. The whole brain mean values of CBF, CBV, and CMRO(2) were 54.3±2.0 mL per 100 g per minute, 4.9±0.4 mL/100 g, and 2.8±0.2 μmoL per g per minute (6.2±0.4 mL per 100 g per minute) in the normal rats, respectively. In the MCAO model rats, all hemodynamic parameters of the infarction area on the occlusion side significantly decreased. The steady-state method with (15)O-labeled HbV is simple and useful to analyze hemodynamic changes in studies with model animals.
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Hurd RE, Yen YF, Tropp J, Pfefferbaum A, Spielman DM, Mayer D. Cerebral dynamics and metabolism of hyperpolarized [1-(13)C]pyruvate using time-resolved MR spectroscopic imaging. J Cereb Blood Flow Metab 2010; 30:1734-41. [PMID: 20588318 PMCID: PMC2975615 DOI: 10.1038/jcbfm.2010.93] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 04/28/2010] [Accepted: 06/02/2010] [Indexed: 01/17/2023]
Abstract
Dynamic hyperpolarized [1-(13)C]pyruvate metabolic imaging in the normal anesthetized rat brain is demonstrated on a clinical 3-T magnetic resonance imaging scanner. A 12-second bolus injection of hyperpolarized [1-(13)C]pyruvate is imaged at a 3-second temporal resolution. The observed dynamics are evaluated with regard to cerebral blood volume (CBV), flow, transport, and metabolic exchange with the cerebral lactate pool. A model for brain [1-(13)C]lactate, based on blood-brain transport kinetics, CBV, and the observed pyruvate dynamics is described.
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Affiliation(s)
- Ralph E Hurd
- Global Applied Science Laboratory, GE Healthcare, Menlo Park, California 94025, USA.
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12
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Knutsson L, Ståhlberg F, Wirestam R. Absolute quantification of perfusion using dynamic susceptibility contrast MRI: pitfalls and possibilities. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2009; 23:1-21. [DOI: 10.1007/s10334-009-0190-2] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 11/11/2009] [Accepted: 11/12/2009] [Indexed: 10/20/2022]
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Cerebral blood volume quantification in a C6 tumor model using gadolinium per (3,6-anhydro) alpha-cyclodextrin as a new magnetic resonance imaging preclinical contrast agent. J Cereb Blood Flow Metab 2008; 28:1017-29. [PMID: 18183033 DOI: 10.1038/sj.jcbfm.9600602] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In magnetic resonance imaging (MRI), cerebral blood volume (CBV) quantification is dependent on the MRI sequence and on the properties of the contrast agents (CAs). By using the rapid steady-state T(1) method, we show the potential of gadolinium per (3,6-anhydro) alpha-cyclodextrin (Gd-ACX), a new MRI paramagnetic CA (inclusion complex of Gd(3+) with per (3,6-anhydro)-alpha-cyclodextrin), for the CBV quantification in the presence of blood-brain barrier lesions. After biocompatibility and relaxivity experiments, in vivo experiments on rats were performed on a C6 tumor model with 0.05 mmol Gd-ACX/kg (<1/10 of the median lethal dose) injected at a 25 mmol/L concentration, inducing neither nephrotoxicity nor hemolysis. On T(1)-weighted images, a signal enhancement of 170% appeared in vessels after injection, but not in the tumor (during the 1 h of observation), in contrast to the 90% signal enhancement obtained with Gd-DOTA (a clinical MRI CA) injected at a T(1) isoefficient dose. This result shows the absence of Gd-ACX extravasation into the tumor tissue and its confinement to the vascular space. Fractional CBV values were found similar to Gd-ACX and Gd-DOTA in healthy brain tissue and in the contralateral hemisphere of tumor-bearing rats, whereas only Gd-ACX was appropriate for CBV quantification in tumor regions.
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