1
|
Ku MC, Kober F, Lai YC, Pohlmann A, Qadri F, Bader M, Carrier L, Niendorf T. Cardiovascular magnetic resonance detects microvascular dysfunction in a mouse model of hypertrophic cardiomyopathy. J Cardiovasc Magn Reson 2021; 23:63. [PMID: 34053450 PMCID: PMC8166121 DOI: 10.1186/s12968-021-00754-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/06/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) related myocardial vascular remodelling may lead to the reduction of myocardial blood supply and a subsequent progressive loss of cardiac function. This process has been difficult to observe and thus their connection remains unclear. Here we used non-invasive myocardial blood flow sensitive CMR to show an impairment of resting myocardial perfusion in a mouse model of naturally occurring HCM. METHODS We used a mouse model (DBA/2 J; D2 mouse strain) that spontaneously carries variants in the two most susceptible HCM genes-Mybpc3 and Myh7 and bears the key features of human HCM. The C57BL/6 J (B6) was used as a reference strain. Mice with either B6 or D2 backgrounds (male: n = 4, female: n = 4) underwent cine-CMR for functional assessment at 9.4 T. Left ventricular (LV) wall thickness was measured in end diastolic phase by cine-CMR. Quantitative myocardial perfusion maps (male: n = 5, female: n = 5 in each group) were acquired from arterial spin labelling (cine ASL-CMR) at rest. Myocardial perfusion values were measured by delineating different regions of interest based on the LV segmentation model in the mid ventricle of the LV myocardium. Directly after the CMR, the mouse hearts were removed for histological assessments to confirm the incidence of myocardial interstitial fibrosis (n = 8 in each group) and small vessel remodelling such as vessel density (n = 6 in each group) and perivascular fibrosis (n = 8 in each group). RESULTS LV hypertrophy was more pronounced in D2 than in B6 mice (male: D2 LV wall thickness = 1.3 ± 0.1 mm vs B6 LV wall thickness = 1.0 ± 0.0 mm, p < 0.001; female: D2 LV wall thickness = 1.0 ± 0.1 mm vs B6 LV wall thickness = 0.8 ± 0.1 mm, p < 0.01). The resting global myocardial perfusion (myocardial blood flow; MBF) was lower in D2 than in B6 mice (end-diastole: D2 MBFglobal = 7.5 ± 0.6 vs B6 MBFglobal = 9.3 ± 1.6 ml/g/min, p < 0.05; end-systole: D2 MBFglobal = 6.6 ± 0.8 vs B6 MBFglobal = 8.2 ± 2.6 ml/g/min, p < 0.01). This myocardial microvascular dysfunction was observed and associated with a reduction in regional MBF, mainly in the interventricular septal and inferior areas of the myocardium. Immunofluorescence revealed a lower number of vessel densities in D2 than in B6 (D2 capillary = 31.0 ± 3.8% vs B6 capillary = 40.7 ± 4.6%, p < 0.05). Myocardial collagen volume fraction (CVF) was significantly higher in D2 LV versus B6 LV mice (D2 CVF = 3.7 ± 1.4% vs B6 CVF = 1.7 ± 0.7%, p < 0.01). Furthermore, a higher ratio of perivascular fibrosis (PFR) was found in D2 than in B6 mice (D2 PFR = 2.3 ± 1.0%, B6 PFR = 0.8 ± 0.4%, p < 0.01). CONCLUSIONS Our work describes an imaging marker using cine ASL-CMR with a potential to monitor vascular and myocardial remodelling in HCM.
Collapse
Affiliation(s)
- Min-Chi Ku
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany.
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, Berlin, Germany.
| | - Frank Kober
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM), Aix-Marseille University, CNRS, Marseille, France
| | - Yi-Ching Lai
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany
| | - Andreas Pohlmann
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany
| | - Fatimunnisa Qadri
- Molecular Biology of Peptide Hormones, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Michael Bader
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, Berlin, Germany
- Molecular Biology of Peptide Hormones, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany
| | - Lucie Carrier
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner site Hamburg/Kiel/Lübeck, Berlin, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle Strasse 10, 13125, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner site Berlin, Berlin, Germany
- Experimental and Clinical Research Center (ECRC), A Joint Cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
| |
Collapse
|
2
|
Kwiatkowski G, Kozerke S. Extended quantitative dynamic contrast-enhanced cardiac perfusion imaging in mice using accelerated data acquisition and spatially distributed, two-compartment exchange modeling. NMR IN BIOMEDICINE 2019; 32:e4123. [PMID: 31209939 DOI: 10.1002/nbm.4123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/25/2019] [Accepted: 05/04/2019] [Indexed: 05/28/2023]
Abstract
The objective of the present work was to improve data acquisition and quantification of dynamic contrast-enhanced perfusion imaging in the in vivo murine heart. Four-fold undersampled data were acquired in 14 mice and reconstructed using k-t SPARSE. A two-compartment exchange model was employed to provide additional characterization of myocardial tissue based on compartment volumes and the permeability surface area product. The feasibility of the proposed method was tested using compartment-based analysis of contrast-enhanced perfusion data acquired with intravascular and extracellular contrast agents. A significantly different permeability surface area product was measured for the intravascular versus extracellular contrast agent (0.13-0.15 ml/g/min vs 0.86-0.88 ml/g/min). The reduced extravasation also resulted in significantly smaller interstitial volumes of the intravascular versus extracellular agent (9.8-11% vs 45-47%). No difference was found for myocardial blood flow (6.5-7.2 ml/g/min vs 6.0-7.0 ml/g/min). The results presented here show that two-compartment exchange modeling in the in vivo murine heart is feasible and gives access to tissue parameters beyond myocardial blood flow.
Collapse
Affiliation(s)
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH, Zurich, Switzerland
| |
Collapse
|
3
|
Wespi P, Steinhauser J, Kwiatkowski G, Kozerke S. Overestimation of cardiac lactate production caused by liver metabolism of hyperpolarized [1- 13 C]pyruvate. Magn Reson Med 2018; 80:1882-1890. [PMID: 29607535 DOI: 10.1002/mrm.27197] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/08/2018] [Accepted: 03/06/2018] [Indexed: 12/20/2022]
Abstract
PURPOSE The purpose of this work was to study the contribution of liver [1-13 C]lactate to the lactate signal detected in the heart following injection of hyperpolarized [1-13 C]pyruvate. METHODS A slice-selective saturation scheme was incorporated into a hybrid metabolic imaging and spectroscopy approach to selectively presaturate lactate in the liver. Imaging and slice-selective spectroscopy of [1-13 C]pyruvate and its downstream metabolites were sequentially interleaved in the same experiment with optional presaturation of liver [1-13 C]lactate. Six healthy rats were measured, and metabolic data in the heart acquired with and without presaturation of liver lactate were compared. RESULTS When using liver lactate presaturation, a statistically significant reduction of the lactate/pyruvate ratio was observed in the spectroscopic data of the left ventricle (0.18 ± 0.03 versus 0.24 ± 0.04; p < .05) as well as in the imaging data of the blood pool (0.05 ± 0.01 versus 0.11 ± 0.01; p < .05). No significant difference in myocardial lactate was observed when using myocardium only as the region of interest in the imaging data (0.08 ± 0.01 versus 0.11 ± 0.02; p = .2). CONCLUSION Liver metabolism leads to statistically significant overestimation of cardiac lactate production in slice-selective or nonselective spectroscopic experiments. Therefore, metabolic imaging is preferred over spectroscopy to separate left-ventricular compartments within the slice and hence avoid contamination of cardiac lactate signals. Alternatively, presaturation pulses should be used in combination with spectroscopy approaches.
Collapse
Affiliation(s)
- Patrick Wespi
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Jonas Steinhauser
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Grzegorz Kwiatkowski
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| |
Collapse
|
4
|
Nezafat M, Ramos IT, Henningsson M, Protti A, Basha T, Botnar RM. Improved segmented modified Look-Locker inversion recovery T1 mapping sequence in mice. PLoS One 2017; 12:e0187621. [PMID: 29121086 PMCID: PMC5679534 DOI: 10.1371/journal.pone.0187621] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 10/04/2017] [Indexed: 12/02/2022] Open
Abstract
Object To develop and evaluate a 2D modified Look-Locker (MOLLI) for high-resolution T1 mapping in mice using a 3T MRI scanner. Materials and methods To allow high-resolution T1 mapping in mice at high heart rates a multi-shot ECG-triggered 2D MOLLI sequence was developed. In the proposed T1 mapping sequence the optimal number of sampling points and pause cardiac cycles following an initial adiabatic inversion pulse was investigated in a phantom. Seven native control and eight mice, 3 days post myocardial infarction (MI) after administration of gadolinium were scanned. Two experienced readers graded the visual T1 map quality. Results In T1 phantoms, there were no significant differences (<0.4% error) between 12, 15 and 20 pause cardiac cycles (p = 0.1, 0.2 and 0.6 respectively) for 8 acquisition cardiac cycles for 600bpm in comparison to the conventional inversion recovery spin echo T1 mapping sequence for short T1’s (<600 ms). Subsequently, all in-vivo scans were performed with 8 data acquisitions and 12 pause cardiac cycles to minimize scan time. The mean native T1 value of myocardium in control animal was 820.5±52 ms. The post-contrast T1 measured 3 days after MI in scar was 264±59 ms and in healthy myocardium was 512±62 ms. The Bland-Altman analysis revealed mean difference of only -1.06% of infarct size percentage between T1 maps and LGE. Conclusions A multi-shot 2D MOLLI sequence has been presented that allows reliable measurement of high spatial resolution T1 maps in mice for heart rates up to 600bpm.
Collapse
Affiliation(s)
- Maryam Nezafat
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, London, United Kingdom
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Isabel T. Ramos
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, London, United Kingdom
| | - Markus Henningsson
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, London, United Kingdom
| | - Andrea Protti
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, London, United Kingdom
| | - Tamer Basha
- Cairo University, Biomedical Engineering Department, Giza, Egypt
| | - René M. Botnar
- Division of Imaging Sciences & Biomedical Engineering, King’s College London, London, United Kingdom
- Pontificia Universidad Católica de Chile, Escuela de Ingeniería, Santiago, Chile
| |
Collapse
|
5
|
Yoon AJ, Do HP, Cen S, Fong MW, Saremi F, Barr ML, Nayak KS. Assessment of segmental myocardial blood flow and myocardial perfusion reserve by adenosine-stress myocardial arterial spin labeling perfusion imaging. J Magn Reson Imaging 2017; 46:413-420. [DOI: 10.1002/jmri.25604] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/05/2016] [Indexed: 01/19/2023] Open
Affiliation(s)
- Andrew J. Yoon
- Department of Medicine, Division of Cardiology, Keck School of Medicine of USC; University of Southern California; Los Angeles California USA
| | - Hung Phi Do
- Department of Physics and Astronomy; University of Southern California; Los Angeles California USA
| | - Steven Cen
- Department of Radiology, Keck School of Medicine of USC; University of Southern California; Los Angeles California USA
| | - Michael W. Fong
- Department of Medicine, Division of Cardiology, Keck School of Medicine of USC; University of Southern California; Los Angeles California USA
| | - Farhood Saremi
- Department of Radiology, Keck School of Medicine of USC; University of Southern California; Los Angeles California USA
| | - Mark L. Barr
- Department of Cardiothoracic Surgery, Keck School of Medicine of USC; University of Southern California; Los Angeles California USA
| | - Krishna S. Nayak
- Ming Hsieh Department of Electrical Engineering; University of Southern California; Los Angeles California USA
| |
Collapse
|
6
|
Vanhoutte L, Gerber BL, Gallez B, Po C, Magat J, Balligand JL, Feron O, Moniotte S. High field magnetic resonance imaging of rodents in cardiovascular research. Basic Res Cardiol 2016; 111:46. [PMID: 27287250 DOI: 10.1007/s00395-016-0565-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 06/01/2016] [Indexed: 02/07/2023]
Abstract
Transgenic and gene knockout rodent models are primordial to study pathophysiological processes in cardiovascular research. Over time, cardiac MRI has become a gold standard for in vivo evaluation of such models. Technical advances have led to the development of magnets with increasingly high field strength, allowing specific investigation of cardiac anatomy, global and regional function, viability, perfusion or vascular parameters. The aim of this report is to provide a review of the various sequences and techniques available to image mice on 7-11.7 T magnets and relevant to the clinical setting in humans. Specific technical aspects due to the rise of the magnetic field are also discussed.
Collapse
Affiliation(s)
- Laetitia Vanhoutte
- Department of Paediatric Cardiology, Cliniques universitaires Saint Luc, Université Catholique de Louvain (UCL), Brussels, Belgium. .,Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium.
| | - Bernhard L Gerber
- Division of Cardiology, Cliniques universitaires Saint Luc, Université Catholique de Louvain (UCL), Brussels, Belgium.,Pole of Cardiovascular Research (CARD), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Bernard Gallez
- Biomedical Magnetic Resonance Unit (REMA), Louvain Drug Research Institute (LDRI), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Chrystelle Po
- CNRS, ICube, FMTS, Institut de Physique Biologique, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Julie Magat
- L'Institut de RYthmologie et de Modélisation Cardiaque (LIRYC), Inserm U1045, Bordeaux, France
| | - Jean-Luc Balligand
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Olivier Feron
- Pole of Pharmacology and Therapeutics (FATH), Institute of Experimental and Clinical Research (IREC), Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Stéphane Moniotte
- Department of Paediatric Cardiology, Cliniques universitaires Saint Luc, Université Catholique de Louvain (UCL), Brussels, Belgium
| |
Collapse
|
7
|
Kober F, Jao T, Troalen T, Nayak KS. Myocardial arterial spin labeling. J Cardiovasc Magn Reson 2016; 18:22. [PMID: 27071861 PMCID: PMC4830031 DOI: 10.1186/s12968-016-0235-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/22/2016] [Indexed: 11/10/2022] Open
Abstract
Arterial spin labeling (ASL) is a cardiovascular magnetic resonance (CMR) technique for mapping regional myocardial blood flow. It does not require any contrast agents, is compatible with stress testing, and can be performed repeatedly or even continuously. ASL-CMR has been performed with great success in small-animals, but sensitivity to date has been poor in large animals and humans and remains an active area of research. This review paper summarizes the development of ASL-CMR techniques, current state-of-the-art imaging methods, the latest findings from pre-clinical and clinical studies, and future directions. We also explain how successful developments in brain ASL and small-animal ASL-CMR have helped to inform developments in large animal and human ASL-CMR.
Collapse
Affiliation(s)
- Frank Kober
- />Aix-Marseille Université, CNRS CRMBM UMR 7339, Centre de Résonance Magnétique Biologique et Médicale, Marseille, France
| | - Terrence Jao
- />Department of Biomedical Engineering, University of Southern California, Los Angeles, California USA
| | - Thomas Troalen
- />Aix-Marseille Université, CNRS CRMBM UMR 7339, Centre de Résonance Magnétique Biologique et Médicale, Marseille, France
| | - Krishna S. Nayak
- />Department of Biomedical Engineering, University of Southern California, Los Angeles, California USA
- />Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California USA
| |
Collapse
|
8
|
Winter P, Kampf T, Helluy X, Gutjahr FT, Meyer CB, Bauer WR, Jakob PM, Herold V. Self-navigation under non-steady-state conditions: Cardiac and respiratory self-gating of inversion recovery snapshot FLASH acquisitions in mice. Magn Reson Med 2016; 76:1887-1894. [PMID: 26743137 DOI: 10.1002/mrm.26068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 10/06/2015] [Accepted: 11/02/2015] [Indexed: 01/30/2023]
Abstract
PURPOSE An algorithm is presented to enable cardiac and respiratory self-gating in combination with Inversion Recovery Look-Locker read-outs. METHODS A radial inversion recovery snapshot FLASH sequence was adapted for retrospective cardiac T1 measurements in mice. Cardiac and respiratory data were extracted from the k-space center of radial projections and an adapted method for retrospective cardiac synchronization is introduced. Electrocardiogram (ECG) data was acquired concurrently for validation of the proposed self-gating technique. T1 maps generated by the proposed technique were compared with maps reconstructed with the ECG reference. RESULTS Respiratory gating and cardiac trigger points could be obtained for the whole time course of the relaxation dynamic and correlate very well to the ECG signal. T1 maps reconstructed with the self-gating technique are in very good agreement with maps reconstructed with the external reference. CONCLUSION The proposed method extends "wireless" cardiac MRI to non-steady-state inversion recovery measurements. T1 maps were generated with a quality comparable to ECG based reconstructions. As the method does not rely on an ECG trigger signal it provides easier animal handling. Magn Reson Med 76:1887-1894, 2016. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Patrick Winter
- Lehrstuhl Für Experimentelle Physik 5, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Thomas Kampf
- Lehrstuhl Für Experimentelle Physik 5, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Xavier Helluy
- Department of Neuroscience, Neuroimaging Research Centre, Ruhr-Universität, Bochum, Germany
| | - Fabian T Gutjahr
- Lehrstuhl Für Experimentelle Physik 5, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Cord B Meyer
- Lehrstuhl Für Experimentelle Physik 5, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Wolfgang R Bauer
- Universität Würzburg, Medizinische Klinik und Poliklinik I, Würzburg, Germany
| | - Peter M Jakob
- Lehrstuhl Für Experimentelle Physik 5, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Volker Herold
- Lehrstuhl Für Experimentelle Physik 5, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| |
Collapse
|
9
|
Abdesselam I, Pepino P, Troalen T, Macia M, Ancel P, Masi B, Fourny N, Gaborit B, Giannesini B, Kober F, Dutour A, Bernard M. Time course of cardiometabolic alterations in a high fat high sucrose diet mice model and improvement after GLP-1 analog treatment using multimodal cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2015; 17:95. [PMID: 26546347 PMCID: PMC4636800 DOI: 10.1186/s12968-015-0198-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/28/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Cardiovascular complications of obesity and diabetes are major health problems. Assessing their development, their link with ectopic fat deposition and their flexibility with therapeutic intervention is essential. The aim of this study was to longitudinally investigate cardiac alterations and ectopic fat accumulation associated with diet-induced obesity using multimodal cardiovascular magnetic resonance (CMR) in mice. The second objective was to monitor cardiac response to exendin-4 (GLP-1 receptor agonist). METHODS Male C57BL6R mice subjected to a high fat (35 %) high sucrose (34 %) (HFHSD) or a standard diet (SD) during 4 months were explored every month with multimodal CMR to determine hepatic and myocardial triglyceride content (HTGC, MTGC) using proton MR spectroscopy, cardiac function with cine cardiac MR (CMR) and myocardial perfusion with arterial spin labeling CMR. Furthermore, mice treated with exendin-4 (30 μg/kg SC BID) after 4 months of diet were explored before and 14 days post-treatment with multimodal CMR. RESULTS HFHSD mice became significantly heavier (+33 %) and displayed glucose homeostasis impairment (1-month) as compared to SD mice, and developed early increase in HTGC (1 month, +59 %) and MTGC (2-month, +63 %). After 3 months, HFHSD mice developed cardiac dysfunction with significantly higher diastolic septum wall thickness (sWtnD) (1.28 ± 0.03 mm vs. 1.12 ± 0.03 mm) and lower cardiac index (0.45 ± 0.06 mL/min/g vs. 0.68 ± 0.07 mL/min/g, p = 0.02) compared to SD mice. A significantly lower cardiac perfusion was also observed (4 months:7.5 ± 0.8 mL/g/min vs. 10.0 ± 0.7 mL/g/min, p = 0.03). Cardiac function at 4 months was negatively correlated to both HTGC and MTGC (p < 0.05). 14-day treatment with Exendin-4 (Ex-4) dramatically reversed all these alterations in comparison with placebo-treated HFHSD. Ex-4 diminished myocardial triglyceride content (-57.8 ± 4.1 %), improved cardiac index (+38.9 ± 10.9 %) and restored myocardial perfusion (+52.8 ± 16.4 %) under isoflurane anesthesia. Interestingly, increased wall thickness and hepatic steatosis reductions were independent of weight loss and glycemia decrease in multivariate analysis (p < 0.05). CONCLUSION CMR longitudinal follow-up of cardiac consequences of obesity and diabetes showed early accumulation of ectopic fat in mice before the occurrence of microvascular and contractile dysfunction. This study also supports a cardioprotective effect of glucagon-like peptide-1 receptor agonist.
Collapse
Affiliation(s)
- Inès Abdesselam
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
| | - Pauline Pepino
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Thomas Troalen
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Michael Macia
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Patricia Ancel
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
| | - Brice Masi
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Natacha Fourny
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Bénédicte Gaborit
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
- Endocrinology, Metabolic diseases and nutrition, CHU Nord, Marseille, France
| | - Benoît Giannesini
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Frank Kober
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France
| | - Anne Dutour
- Aix-Marseille Université, NORT, Inserm U1062/Inra1260, 13385, Marseille, France
- Endocrinology, Metabolic diseases and nutrition, CHU Nord, Marseille, France
| | - Monique Bernard
- Aix-Marseille Université, CNRS, CRMBM, UMR7339, 27, Bd Jean Moulin, 13385, Marseille, France.
| |
Collapse
|
10
|
Santos A, Fernández-Friera L, Villalba M, López-Melgar B, España S, Mateo J, Mota RA, Jiménez-Borreguero J, Ruiz-Cabello J. Cardiovascular imaging: what have we learned from animal models? Front Pharmacol 2015; 6:227. [PMID: 26539113 PMCID: PMC4612690 DOI: 10.3389/fphar.2015.00227] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/22/2015] [Indexed: 12/17/2022] Open
Abstract
Cardiovascular imaging has become an indispensable tool for patient diagnosis and follow up. Probably the wide clinical applications of imaging are due to the possibility of a detailed and high quality description and quantification of cardiovascular system structure and function. Also phenomena that involve complex physiological mechanisms and biochemical pathways, such as inflammation and ischemia, can be visualized in a non-destructive way. The widespread use and evolution of imaging would not have been possible without animal studies. Animal models have allowed for instance, (i) the technical development of different imaging tools, (ii) to test hypothesis generated from human studies and finally, (iii) to evaluate the translational relevance assessment of in vitro and ex-vivo results. In this review, we will critically describe the contribution of animal models to the use of biomedical imaging in cardiovascular medicine. We will discuss the characteristics of the most frequent models used in/for imaging studies. We will cover the major findings of animal studies focused in the cardiovascular use of the repeatedly used imaging techniques in clinical practice and experimental studies. We will also describe the physiological findings and/or learning processes for imaging applications coming from models of the most common cardiovascular diseases. In these diseases, imaging research using animals has allowed the study of aspects such as: ventricular size, shape, global function, and wall thickening, local myocardial function, myocardial perfusion, metabolism and energetic assessment, infarct quantification, vascular lesion characterization, myocardial fiber structure, and myocardial calcium uptake. Finally we will discuss the limitations and future of imaging research with animal models.
Collapse
Affiliation(s)
- Arnoldo Santos
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain ; Madrid-MIT M+Visión Consortium Madrid, Spain ; Department of Anesthesia, Massachusetts General Hospital, Harvard Medical School Boston, MA, USA
| | - Leticia Fernández-Friera
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Hospital Universitario HM Monteprincipe Madrid, Spain
| | - María Villalba
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain
| | - Beatriz López-Melgar
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Hospital Universitario HM Monteprincipe Madrid, Spain
| | - Samuel España
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain ; Madrid-MIT M+Visión Consortium Madrid, Spain
| | - Jesús Mateo
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain
| | - Ruben A Mota
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Charles River Barcelona, Spain
| | - Jesús Jiménez-Borreguero
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; Cardiac Imaging Department, Hospital de La Princesa Madrid, Spain
| | - Jesús Ruiz-Cabello
- Centro Nacional de Investigaciones Cardiovasculares Carlos III Madrid, Spain ; CIBER de Enfermedades Respiratorias (CIBERES) Madrid, Spain ; Universidad Complutense de Madrid Madrid, Spain
| |
Collapse
|
11
|
Yeh JSM, Sennoga CA, McConnell E, Eckersley R, Tang MX, Nourshargh S, Seddon JM, Haskard DO, Nihoyannopoulos P. Quantitative ultrasound molecular imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2015; 41:2478-2496. [PMID: 26044707 DOI: 10.1016/j.ultrasmedbio.2015.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 03/10/2015] [Accepted: 04/21/2015] [Indexed: 06/04/2023]
Abstract
Ultrasound molecular imaging using targeting microbubbles is predominantly a semi-quantitative tool, thus limiting its potential diagnostic power and clinical applications. In the work described here, we developed a novel method for acoustic quantification of molecular expression. E-Selectin expression in the mouse heart was induced by lipopolysaccharide. Real-time ultrasound imaging of E-selectin expression in the heart was performed using E-selectin-targeting microbubbles and a clinical ultrasound scanner in contrast pulse sequencing mode at 14 MHz, with a mechanical index of 0.22-0.26. The level of E-selectin expression was quantified using a novel time-signal intensity curve analytical method based on bubble elimination, which consisted of curve-fitting the bi-exponential equation [Formula: see text] to the elimination phase of the myocardial time-signal intensity curve. Ar and Af represent the maximum signal intensities of the retained and freely circulating bubbles in the myocardium, respectively; λr and λf represent the elimination rate constants of the retained and freely circulating bubbles in the myocardium, respectively. Ar correlated strongly with the level of E-selectin expression (|r|>0.8), determined using reverse transcriptase real-time quantitative polymerase chain reaction, and the duration of post-lipopolysaccharide treatment-both linearly related to cell surface E-selectin protein (actual bubble target) concentration in the expression range imaged. Compared with a conventional acoustic quantification method (which used retained bubble signal intensity at 20 min post-bubble injection), this new approach exhibited greater dynamic range and sensitivity and was able to simultaneously quantify other useful characteristics (e.g., the microbubble half-life). In conclusion, quantitative determination of the level of molecular expression is feasible acoustically using a time-signal intensity curve analytical method based on bubble elimination.
Collapse
Affiliation(s)
- James Shue-Min Yeh
- National Heart and Lung Institute, Imperial College London, London, UK; Department of Cardiology, Hammersmith Hospital, London, UK; Imaging Sciences Department, Medical Research Council, Imperial College London, London, UK
| | - Charles A Sennoga
- Imaging Sciences Department, Medical Research Council, Imperial College London, London, UK; Department of Chemistry, Imperial College London, London, UK
| | - Ellen McConnell
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Robert Eckersley
- Imaging Sciences Department, Medical Research Council, Imperial College London, London, UK
| | - Meng-Xing Tang
- Department of Bioengineering, Imperial College London, London, UK
| | - Sussan Nourshargh
- National Heart and Lung Institute, Imperial College London, London, UK; William Harvey Research Institute, Queen Mary, University of London, London, UK
| | - John M Seddon
- Department of Chemistry, Imperial College London, London, UK
| | - Dorian O Haskard
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Petros Nihoyannopoulos
- National Heart and Lung Institute, Imperial College London, London, UK; Department of Cardiology, Hammersmith Hospital, London, UK.
| |
Collapse
|
12
|
Bakermans AJ, Abdurrachim D, Moonen RPM, Motaal AG, Prompers JJ, Strijkers GJ, Vandoorne K, Nicolay K. Small animal cardiovascular MR imaging and spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 88-89:1-47. [PMID: 26282195 DOI: 10.1016/j.pnmrs.2015.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
The use of MR imaging and spectroscopy for studying cardiovascular disease processes in small animals has increased tremendously over the past decade. This is the result of the remarkable advances in MR technologies and the increased availability of genetically modified mice. MR techniques provide a window on the entire timeline of cardiovascular disease development, ranging from subtle early changes in myocardial metabolism that often mark disease onset to severe myocardial dysfunction associated with end-stage heart failure. MR imaging and spectroscopy techniques play an important role in basic cardiovascular research and in cardiovascular disease diagnosis and therapy follow-up. This is due to the broad range of functional, structural and metabolic parameters that can be quantified by MR under in vivo conditions non-invasively. This review describes the spectrum of MR techniques that are employed in small animal cardiovascular disease research and how the technological challenges resulting from the small dimensions of heart and blood vessels as well as high heart and respiratory rates, particularly in mice, are tackled.
Collapse
Affiliation(s)
- Adrianus J Bakermans
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Desiree Abdurrachim
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Rik P M Moonen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Abdallah G Motaal
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Gustav J Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Katrien Vandoorne
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
| |
Collapse
|
13
|
Balestra GM, Aalders MCG, Specht PAC, Ince C, Mik EG. Oxygenation measurement by multi-wavelength oxygen-dependent phosphorescence and delayed fluorescence: catchment depth and application in intact heart. JOURNAL OF BIOPHOTONICS 2015; 8:615-628. [PMID: 25250821 DOI: 10.1002/jbio.201400054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/11/2014] [Accepted: 08/18/2014] [Indexed: 06/03/2023]
Abstract
Oxygen delivery and metabolism represent key factors for organ function in health and disease. We describe the optical key characteristics of a technique to comprehensively measure oxygen tension (PO(2)) in myocardium, using oxygen-dependent quenching of phosphorescence and delayed fluorescence of porphyrins, by means of Monte Carlo simulations and ex vivo experiments. Oxyphor G2 (microvascular PO(2)) was excited at 442 nm and 632 nm and protoporphyrin IX (mitochondrial PO(2)) at 510 nm. This resulted in catchment depths of 161 (86) µm, 350 (307) µm and 262 (255) µm respectively, as estimated by Monte Carlo simulations and ex vivo experiments (brackets). The feasibility to detect changes in oxygenation within separate anatomical compartments is demonstrated in rat heart in vivo. Schematic of ex vivo measurements.
Collapse
Affiliation(s)
- Gianmarco M Balestra
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Medical Intensive Care, University Hospital Basel, Switzerland
- Department of Translational Physiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Maurice C G Aalders
- Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, The Netherlands
| | - Patricia A C Specht
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Can Ince
- Department of Translational Physiology, Academic Medical Center, Amsterdam, The Netherlands
| | - Egbert G Mik
- Department of Anesthesiology, Laboratory of Experimental Anesthesiology, Erasmus MC - University Medical Center Rotterdam, Rotterdam, The Netherlands
| |
Collapse
|
14
|
Naresh NK, Chen X, Moran E, Tian Y, French BA, Epstein FH. Repeatability and variability of myocardial perfusion imaging techniques in mice: Comparison of arterial spin labeling and first-pass contrast-enhanced MRI. Magn Reson Med 2015; 75:2394-405. [PMID: 26190350 DOI: 10.1002/mrm.25769] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/14/2015] [Accepted: 04/20/2015] [Indexed: 11/08/2022]
Abstract
PURPOSE Preclinical imaging of myocardial blood flow (MBF) can elucidate molecular mechanisms underlying cardiovascular disease. We compared the repeatability and variability of two methods, first-pass MRI and arterial spin labeling (ASL), for imaging MBF in mice. METHODS Quantitative perfusion MRI in mice was performed using both methods at rest, with a vasodilator, and one day after myocardial infarction. Image quality (score of 1-5; 5 best), between-session coefficient of variability (CVbs ), intra-user coefficient of variability (CVintra-user ), and inter-user coefficient of variability (CVinter-user ) were assessed. Acquisition time was 1-2 min for first-pass MRI and approximately 40 min for ASL. RESULTS Image quality was higher for ASL (3.94 ± 0.09 versus 2.88 ± 0.10; P < 0.05). Infarct zone CVbs was lower with first-pass (17 ± 3% versus 46 ± 9%; P < 0.05). The stress perfusion CVintra-user was lower for ASL (3 ± 1% versus 14 ± 3%; P < 0.05). The stress perfusion CVinter-user was lower for ASL (4 ± 1% versus 17 ± 4%; P < 0.05). CONCLUSION For low MBF conditions such as infarct, first-pass MRI is preferred due to better repeatability and variability. At high MBF such as at vasodilation, ASL may be more suitable due to superior image quality and lower user variability. First-pass MRI has a substantial speed advantage. Magn Reson Med 75:2394-2405, 2016. © 2015 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Nivedita K Naresh
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Xiao Chen
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Eric Moran
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Yikui Tian
- Department of Surgery, University of Virginia, Charlottesville, Virginia, USA
| | - Brent A French
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Frederick H Epstein
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA.,Department of Radiology, University of Virginia, Charlottesville, Virginia, USA
| |
Collapse
|
15
|
Yeh JSM, Sennoga CA, McConnell E, Eckersley R, Tang MX, Nourshargh S, Seddon JM, Haskard DO, Nihoyannopoulos P. A Targeting Microbubble for Ultrasound Molecular Imaging. PLoS One 2015; 10:e0129681. [PMID: 26161541 PMCID: PMC4498921 DOI: 10.1371/journal.pone.0129681] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 05/12/2015] [Indexed: 11/30/2022] Open
Abstract
Rationale Microbubbles conjugated with targeting ligands are used as contrast agents for ultrasound molecular imaging. However, they often contain immunogenic (strept)avidin, which impedes application in humans. Although targeting bubbles not employing the biotin-(strept)avidin conjugation chemistry have been explored, only a few reached the stage of ultrasound imaging in vivo, none were reported/evaluated to show all three of the following properties desired for clinical applications: (i) low degree of non-specific bubble retention in more than one non-reticuloendothelial tissue; (ii) effective for real-time imaging; and (iii) effective for acoustic quantification of molecular targets to a high degree of quantification. Furthermore, disclosures of the compositions and methodologies enabling reproduction of the bubbles are often withheld. Objective To develop and evaluate a targeting microbubble based on maleimide-thiol conjugation chemistry for ultrasound molecular imaging. Methods and Results Microbubbles with a previously unreported generic (non-targeting components) composition were grafted with anti-E-selectin F(ab’)2 using maleimide-thiol conjugation, to produce E-selectin targeting microbubbles. The resulting targeting bubbles showed high specificity to E-selectin in vitro and in vivo. Non-specific bubble retention was minimal in at least three non-reticuloendothelial tissues with inflammation (mouse heart, kidneys, cremaster). The bubbles were effective for real-time ultrasound imaging of E-selectin expression in the inflamed mouse heart and kidneys, using a clinical ultrasound scanner. The acoustic signal intensity of the targeted bubbles retained in the heart correlated strongly with the level of E-selectin expression (|r|≥0.8), demonstrating a high degree of non-invasive molecular quantification. Conclusions Targeting microbubbles for ultrasound molecular imaging, based on maleimide-thiol conjugation chemistry and the generic composition described, may possess properties (i)–(iii) desired for clinical applications.
Collapse
Affiliation(s)
- James Shue-Min Yeh
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- Department of Cardiology, Hammersmith Hospital, London, United Kingdom
- Imaging Sciences Department, Medical Research Council, Imperial College London, London, United Kingdom
| | - Charles A. Sennoga
- Imaging Sciences Department, Medical Research Council, Imperial College London, London, United Kingdom
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Ellen McConnell
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Robert Eckersley
- Imaging Sciences Department, Medical Research Council, Imperial College London, London, United Kingdom
| | - Meng-Xing Tang
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Sussan Nourshargh
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- William Harvey Research Institute, Queen Mary, University of London, London, United Kingdom
| | - John M. Seddon
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Dorian O. Haskard
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Petros Nihoyannopoulos
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- Department of Cardiology, Hammersmith Hospital, London, United Kingdom
- * E-mail:
| |
Collapse
|
16
|
Lau AZ, Miller JJ, Robson MD, Tyler DJ. Cardiac perfusion imaging using hyperpolarized (13)C urea using flow sensitizing gradients. Magn Reson Med 2015; 75:1474-83. [PMID: 25991580 PMCID: PMC4556069 DOI: 10.1002/mrm.25713] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/25/2015] [Accepted: 03/05/2015] [Indexed: 01/18/2023]
Abstract
Purpose To demonstrate the feasibility of imaging the first passage of a bolus of hyperpolarized 13C urea through the rodent heart using flow‐sensitizing gradients to reduce signal from the blood pool. Methods A flow‐sensitizing bipolar gradient was optimized to reduce the bright signal within the cardiac chambers, enabling improved contrast of the agent within the tissue capillary bed. The gradient was incorporated into a dynamic golden angle spiral 13C imaging sequence. Healthy rats were scanned during rest (n = 3) and under adenosine stress‐induced hyperemia (n = 3). Results A two‐fold increase in myocardial perfusion relative to rest was detected during adenosine stress‐induced hyperemia, consistent with a myocardial perfusion reserve of two in rodents. Conclusion The new pulse sequence was used to obtain dynamic images of the first passage of hyperpolarized 13C urea in the rodent heart, without contamination from bright signal within the neighboring cardiac lumen. This probe of myocardial perfusion is expected to enable new hyperpolarized 13C studies in which the cardiac metabolism/perfusion mismatch can be identified. Magn Reson Med, 2015. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Magn Reson Med 75:1474–1483, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance.
Collapse
Affiliation(s)
- Angus Z Lau
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, United Kingdom.,Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom
| | - Jack J Miller
- Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom.,Department of Physics, Clarendon Laboratory, University of Oxford, United Kingdom
| | - Matthew D Robson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, United Kingdom
| | - Damian J Tyler
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, United Kingdom.,Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom
| |
Collapse
|
17
|
Gutjahr FT, Kampf T, Winter P, Meyer CB, Williams T, Jakob PM, Bauer WR, Ziener CH, Helluy X. Quantification of perfusion in murine myocardium: A retrospectively triggered T1 -based ASL method using model-based reconstruction. Magn Reson Med 2014; 74:1705-15. [PMID: 25446550 DOI: 10.1002/mrm.25526] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/06/2014] [Accepted: 10/20/2014] [Indexed: 11/12/2022]
Abstract
PURPOSE A method for the quantification of perfusion in murine myocardium is demonstrated. The method allows for the reconstruction of perfusion maps on arbitrary time points in the heart cycle while addressing problems that arise due to the irregular heart beat of mice. METHODS A flow-sensitive alternating inversion recovery arterial spin labeling method using an untriggered FLASH-read out with random sampling is used. Look-Locker conditions are strictly maintained. No dummy pulses or mechanism to reduce deviation from Look-Locker conditions are needed. Electrocardiogram and respiratory data are recorded for retrospective gating and triggering. A model-based technique is used to reconstruct missing k-space data to cope with the undersampling inherent in retrospectively gated methods. Acquisition and reconstruction were validated numerically and in phantom measurements before in vivo experimentation. RESULTS Quantitative perfusion maps were acquired within a single slice measurement time of 11 min. Perfusion values are in good accordance to literature values. Myocardial infarction could be clearly visualized and results were confirmed with histological results. CONCLUSION The proposed method is capable of producing quantitative perfusion maps on arbitrary positions in the heart cycle within a short measurement time. The method is robust against irregular breathing patterns and heart rate changes and can be implemented on all scanners.
Collapse
Affiliation(s)
- Fabian T Gutjahr
- Universität Würzburg, Lehrstuhl für Experimentelle Physik 5, Am Hubland, 97074, Würzburg, Germany.,Comprehensive Heart Failure Center, Core Facility Imaging, Straubmühlweg 2a, 97078, Würzburg, Germany
| | - Thomas Kampf
- Universität Würzburg, Lehrstuhl für Experimentelle Physik 5, Am Hubland, 97074, Würzburg, Germany
| | - Patrick Winter
- Universität Würzburg, Lehrstuhl für Experimentelle Physik 5, Am Hubland, 97074, Würzburg, Germany
| | - Cord B Meyer
- Universität Würzburg, Lehrstuhl für Experimentelle Physik 5, Am Hubland, 97074, Würzburg, Germany
| | - Tatjana Williams
- Universität Würzburg, Medizinische Klinik und Poliklinik I, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Peter M Jakob
- Universität Würzburg, Lehrstuhl für Experimentelle Physik 5, Am Hubland, 97074, Würzburg, Germany
| | - Wolfgang R Bauer
- Universität Würzburg, Medizinische Klinik und Poliklinik I, Oberdürrbacher Straße 6, 97080, Würzburg, Germany
| | - Christian H Ziener
- German Cancer Research Center DKFZ, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Xavier Helluy
- Universität Würzburg, Lehrstuhl für Experimentelle Physik 5, Am Hubland, 97074, Würzburg, Germany
| |
Collapse
|
18
|
Jiang K, Li W, Li W, Jiao S, Castel L, Van Wagoner DR, Yu X. Rapid multislice T1 mapping of mouse myocardium: Application to quantification of manganese uptake in α-Dystrobrevin knockout mice. Magn Reson Med 2014; 74:1370-9. [PMID: 25408542 DOI: 10.1002/mrm.25533] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 09/26/2014] [Accepted: 10/23/2014] [Indexed: 12/27/2022]
Abstract
PURPOSE The aim of this study was to develop a rapid, multislice cardiac T1 mapping method in mice and to apply the method to quantify manganese (Mn(2+)) uptake in a mouse model with altered Ca(2+) channel activity. METHODS An electrocardiography-triggered multislice saturation-recovery Look-Locker method was developed and validated both in vitro and in vivo. A two-dose study was performed to investigate the kinetics of T1 shortening, Mn(2+) relaxivity in myocardium, and the impact of Mn(2+) on cardiac function. The sensitivity of Mn(2+)-enhanced MRI in detecting subtle changes in altered Ca(2+) channel activity was evaluated in a mouse model with α-dystrobrevin knockout. RESULTS Validation studies showed strong agreement between the current method and an established method. High Mn(2+) dose led to significantly accelerated T1 shortening. Heart rate decreased during Mn(2+) infusion, while ejection ratio increased slightly at the end of imaging protocol. No statistical difference in cardiac function was detected between the two dose groups. Mice with α-dystrobrevin knockout showed enhanced Mn(2+) uptake in vivo. In vitro patch-clamp study showed increased Ca(2+) channel activity. CONCLUSION The saturation recovery method provides rapid T1 mapping in mouse hearts, which allowed sensitive detection of subtle changes in Mn(2+) uptake in α-dystrobrevin knockout mice.
Collapse
Affiliation(s)
- Kai Jiang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wen Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wei Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sen Jiao
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Laurie Castel
- Department of Molecular Cardiology, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
| |
Collapse
|
19
|
Meßner NM, Zöllner FG, Kalayciyan R, Schad LR. Pre-clinical functional Magnetic Resonance Imaging Part II: The heart. Z Med Phys 2014; 24:307-22. [PMID: 25023418 DOI: 10.1016/j.zemedi.2014.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 05/09/2014] [Accepted: 06/17/2014] [Indexed: 12/21/2022]
Abstract
One third of all deaths worldwide in 2008 were caused by cardiovascular diseases (CVD), and the incidence of CVD related deaths rises ever more. Thus, improved imaging techniques and modalities are needed for the evaluation of cardiac morphology and function. Cardiac magnetic resonance imaging (CMRI) is a minimally invasive technique that is increasingly important due to its high spatial and temporal resolution, its high soft tissue contrast and its ability of functional and quantitative imaging. It is widely accepted as the gold standard of cardiac functional analysis. In the short period of small animal MRI, remarkable progress has been achieved concerning new, fast imaging schemes as well as purpose-built equipment. Dedicated small animal scanners allow for tapping the full potential of recently developed animal models of cardiac disease. In this paper, we review state-of-the-art cardiac magnetic resonance imaging techniques and applications in small animals at ultra-high fields (UHF).
Collapse
Affiliation(s)
- Nadja M Meßner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
| | - Raffi Kalayciyan
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| |
Collapse
|
20
|
Naresh NK, Chen X, Roy RJ, Antkowiak PF, Annex BH, Epstein FH. Accelerated dual-contrast first-pass perfusion MRI of the mouse heart: development and application to diet-induced obese mice. Magn Reson Med 2014; 73:1237-45. [PMID: 24760707 DOI: 10.1002/mrm.25238] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/19/2014] [Accepted: 03/11/2014] [Indexed: 12/23/2022]
Abstract
PURPOSE Gene-modified mice may be used to elucidate molecular mechanisms underlying abnormal myocardial blow flow (MBF). We sought to develop a quantitative myocardial perfusion imaging technique for mice and to test the hypothesis that myocardial perfusion reserve (MPR) is reduced in a mouse model of diet-induced obesity (DIO). METHODS A dual-contrast saturation-recovery sequence with ky -t undersampling and a motion-compensated compressed sensing reconstruction algorithm was developed for first-pass MRI on a small-bore 7 Tesla system. Control mice were imaged at rest and with the vasodilators ATL313 and Regadenoson (n = 6 each). In addition, we imaged mice fed a high-fat diet (HFD) for 24 weeks. RESULTS In control mice, MBF was 5.7 ± 0.8 mL/g/min at rest and it increased to 11.8 ± 0.6 mL/g/min with ATL313 and to 10.4 ± 0.3 mL/g/min with Regadenoson. In HFD mice, we detected normal resting MBF (5.6 ± 0.4 versus 5.0 ± 0.3 on control diet), low MBF at stress (7.7 ± 0.4 versus 10.4 ± 0.3 on control diet, P < 0.05), and reduced MPR (1.4 ± 0.2 versus 2.0 ± 0.3 on control diet, P < 0.05). CONCLUSION Accelerated dual-contrast first-pass MRI with motion-compensated compressed sensing provides spatiotemporal resolution suitable for measuring MBF in free-breathing mice, and detected reduced MPR in DIO mice. These techniques may be used to study molecular mechanisms that underlie abnormal myocardial perfusion.
Collapse
Affiliation(s)
- Nivedita K Naresh
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | | | | | | | | | | |
Collapse
|
21
|
Troalen T, Capron T, Bernard M, Kober F. In vivo characterization of rodent cyclic myocardial perfusion variation at rest and during adenosine-induced stress using cine-ASL cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2014; 16:18. [PMID: 24548535 PMCID: PMC3937054 DOI: 10.1186/1532-429x-16-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 02/10/2014] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Assessment of cyclic myocardial blood flow (MBF) variations can be an interesting addition to the characterization of microvascular function and its alterations. To date, totally non-invasive in vivo methods with this capability are still lacking. As an original technique, a cine arterial spin labeling (ASL) cardiovascular magnetic resonance approach is demonstrated to be able to produce dynamic MBF maps across the cardiac cycle in rats. METHOD High-resolution MBF maps in left ventricular myocardium were computed from steady-state perfusion-dependent gradient-echo cine images produced by the cine-ASL sequence. Cyclic changes of MBF over the entire cardiac cycle in seven normal rats were analyzed quantitatively every 6 ms at rest and during adenosine-induced stress. RESULTS The study showed a significant MBF increase from end-systole (ES) to end-diastole (ED) in both physiological states. Mean MBF over the cardiac cycle within the group was 5.5 ± 0.6 mL g(-1) min(-1) at rest (MBFMin = 4.7 ± 0.8 at ES and MBFMax = 6.5 ± 0.6 mL g(-1) min(-1) at ED, P = 0.0007). Mean MBF during adenosine-induced stress was 12.8 ± 0.7mL g(-1) min(-1) (MBFMin = 11.7±1.0 at ES and MBFMax = 14.2 ± 0.7 mL g(-1) min(-1) at ED, P = 0.0007). MBF percentage relative variations were significantly different with 27.2 ± 9.3% at rest and 17.8 ± 7.1% during adenosine stress (P = 0.014). The dynamic analysis also showed a time shift of peak MBF within the cardiac cycle during stress. CONCLUSION The cyclic change of myocardial perfusion was examined by mapping MBF with a steady-pulsed ASL approach. Dynamic MBF maps were obtained with high spatial and temporal resolution (6 ms) demonstrating the feasibility of non-invasively mapping cyclic myocardial perfusion variation at rest and during adenosine stress. In a pathological context, detailed assessment of coronary responses to infused vasodilators may give valuable complementary information on microvascular functional defects in disease models.
Collapse
Affiliation(s)
- Thomas Troalen
- Aix-Marseille Université, CNRS, CRMBM UMR 7339, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Thibaut Capron
- Aix-Marseille Université, CNRS, CRMBM UMR 7339, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Monique Bernard
- Aix-Marseille Université, CNRS, CRMBM UMR 7339, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Frank Kober
- Aix-Marseille Université, CNRS, CRMBM UMR 7339, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| |
Collapse
|
22
|
van Nierop BJ, Coolen BF, Bax NA, Dijk WJR, van Deel ED, Duncker DJ, Nicolay K, Strijkers GJ. Myocardial perfusion MRI shows impaired perfusion of the mouse hypertrophic left ventricle. Int J Cardiovasc Imaging 2014; 30:619-28. [DOI: 10.1007/s10554-014-0369-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 01/15/2014] [Indexed: 10/25/2022]
|
23
|
Do HP, Jao TR, Nayak KS. Myocardial arterial spin labeling perfusion imaging with improved sensitivity. J Cardiovasc Magn Reson 2014; 16:15. [PMID: 24467918 PMCID: PMC3913326 DOI: 10.1186/1532-429x-16-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 01/22/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Myocardial arterial spin labeling (ASL) is a noninvasive MRI based technique that is capable of measuring myocardial blood flow (MBF) in humans. It suffers from poor sensitivity to MBF due to high physiological noise (PN). This study aims to determine if the sensitivity of myocardial ASL to MBF can be improved by reducing image acquisition time, via parallel imaging. METHODS Myocardial ASL scans were performed in 7 healthy subjects at rest using flow-sensitive alternating inversion recovery (FAIR) tagging and balanced steady state free precession (SSFP) imaging. Sensitivity encoding (SENSE) with a reduction factor of 2 was used to shorten each image acquisition from roughly 300 ms per heartbeat to roughly 150 ms per heartbeat. A paired Student's t-test was performed to compare measurements of myocardial blood flow (MBF) and physiological noise (PN) from the reference and accelerated methods. RESULTS The measured PN (mean ± standard deviation) was 0.20 ± 0.08 ml/g/min for the reference method and 0.08 ± 0.05 ml/g/min for the accelerated method, corresponding to a 60% reduction. PN measured from the accelerated method was found to be significantly lower than that of the reference method (p=0.0059). There was no significant difference between MBF measured from the accelerated and reference ASL methods (p=0.7297). CONCLUSIONS In this study, significant PN reduction was achieved by shortening the acquisition window using parallel imaging with no significant impact on the measured MBF. This indicates an improvement in sensitivity to MBF and may also enable the imaging of subjects with higher heart rates and imaging during systole.
Collapse
Affiliation(s)
- Hung Phi Do
- Department of Physics and Astronomy, University of Southern California, 3740 McClintock Ave, EEB 400, Los Angeles, CA 90089-2564, USA
| | - Terrence R Jao
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Krishna S Nayak
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
24
|
Zhang H, Ye Q, Zheng J, Schelbert EB, Hitchens TK, Ho C. Improve myocardial T1 measurement in rats with a new regression model: application to myocardial infarction and beyond. Magn Reson Med 2013; 72:737-48. [PMID: 24142881 DOI: 10.1002/mrm.24988] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 08/13/2013] [Accepted: 09/15/2013] [Indexed: 11/09/2022]
Abstract
PURPOSE To improve myocardial and blood T1 measurements with a multi-variable T1 fitting model specifically modified for a segmented multi-shot FLASH sequence. METHODS The proposed method was first evaluated in a series of phantoms simulating realistic tissues, and then in healthy rats (n = 8) and rats with acute myocardial infarction (MI) induced by coronary artery ligation (n = 8). RESULTS By taking into account the saturation effect caused by sampling α-train pulses, and the longitudinal magnetization recovery between readouts, our model provided more accurate T1 estimate than the conventional three-parameter fit in phantoms under realistic gating procedures (error of -0.42 ± 1.73% versus -3.40 ± 1.46%, respectively, when using the measured inversion efficiency, β). The baseline myocardial T1 values in healthy rats was 1636.3 ± 23.4 ms at 7 Tesla. One day postligation, the T1 values in the remote and proximal myocardial areas were 1637.5 ± 62.6 ms and 1740.3 ± 70.5 ms, respectively. In rats with acute MI, regional differences in myocardial T1 values were observed both before and after the administration of gadolinium. CONCLUSION The proposed method has improved T1 estimate as validated in phantoms and could advance applications in rodents using quantitative myocardial T1 mapping.
Collapse
Affiliation(s)
- Haosen Zhang
- Pittsburgh NMR Center for Biomedical Research, Department of Biological Science, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | | | | | | | | | | |
Collapse
|
25
|
Kampf T, Helluy X, Gutjahr FT, Winter P, Meyer CB, Jakob PM, Bauer WR, Ziener CH. Myocardial perfusion quantification using the T
1
-based FAIR-ASL method: The influence of heart anatomy, cardiopulmonary blood flow and look-locker readout. Magn Reson Med 2013; 71:1784-97. [DOI: 10.1002/mrm.24843] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 05/07/2013] [Accepted: 05/22/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Thomas Kampf
- Universität Würzburg; Lehrstuhl für Experimentelle Physik 5 Am Hubland Würzburg Germany
| | - Xavier Helluy
- Universität Würzburg; Lehrstuhl für Experimentelle Physik 5 Am Hubland Würzburg Germany
| | - Fabian T. Gutjahr
- Universität Würzburg; Lehrstuhl für Experimentelle Physik 5 Am Hubland Würzburg Germany
| | - Patrick Winter
- Universität Würzburg; Lehrstuhl für Experimentelle Physik 5 Am Hubland Würzburg Germany
| | - Cord B. Meyer
- Universität Würzburg; Lehrstuhl für Experimentelle Physik 5 Am Hubland Würzburg Germany
| | - Peter M. Jakob
- Universität Würzburg; Lehrstuhl für Experimentelle Physik 5 Am Hubland Würzburg Germany
| | - Wolfgang R. Bauer
- Universität Würzburg, Medizinische Klinik und Poliklinik I; Oberdürrbacher Straße 6 Würzburg Germany
| | - Christian H. Ziener
- German Cancer Research Center DKFZ; Im Neuenheimer Feld 280 Heidelberg Germany
| |
Collapse
|
26
|
Blömer N, Pachel C, Hofmann U, Nordbeck P, Bauer W, Mathes D, Frey A, Bayer B, Vogel B, Ertl G, Bauersachs J, Frantz S. 5-Lipoxygenase facilitates healing after myocardial infarction. Basic Res Cardiol 2013; 108:367. [PMID: 23812248 PMCID: PMC3709074 DOI: 10.1007/s00395-013-0367-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 05/31/2013] [Accepted: 06/14/2013] [Indexed: 12/13/2022]
Abstract
Early healing after myocardial infarction (MI) is characterized by a strong inflammatory reaction. Most leukotrienes are pro-inflammatory and are therefore potential mediators of healing and remodeling after myocardial ischemia. The enzyme 5-lipoxygenase (5-LOX) has a key role in the transformation of arachidonic acid in leukotrienes. Thus, we tested the effect of 5-LOX on healing after MI. After chronic coronary artery ligation, early mortality was significantly increased in 5-LOX−/− when compared to matching wildtype (WT) mice due to left ventricular rupture. This effect could be reproduced in mice treated with the 5-LOX inhibitor Zileuton. A perfusion mismatch due to the vasoactive potential of leukotrienes is not responsible for left ventricular rupture since local blood flow assessed by magnetic resonance perfusion measurements was not different. However, after MI, there was an accentuation of the inflammatory reaction with an increase of pro-inflammatory macrophages. Yet, mortality was not changed in chimeric mice (WT vs. 5-LOX−/− bone marrow in 5-LOX−/− animals), indicating that an altered function of 5-LOX−/− inflammatory cells is not responsible for the phenotype. Collagen production and accumulation of fibroblasts were significantly reduced in 5-LOX−/− mice in vivo after MI. This might be due to an impaired migration of 5-LOX−/− fibroblasts, as shown in vitro to serum. In conclusion, a lack or inhibition of 5-LOX increases mortality after MI because of healing defects. This is not mediated by a change in local blood flow, but through an altered inflammation and/or fibroblast function.
Collapse
Affiliation(s)
- Nadja Blömer
- Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Abstract
RATIONALE The spatial distribution of blood flow in the hearts of genetically modified mice is a phenotype of interest because derangements in blood flow may precede detectable changes in organ function. However, quantifying the regional distribution of blood flow within organs of mice is challenging because of the small organ volume and the high resolution required to observe spatial differences in flow. Traditional microsphere methods in which the numbers of microspheres per region are indirectly estimated from radioactive counts or extracted fluorescence have been limited to larger organs for 2 reasons; to ensure statistical confidence in the measured flow per region and to be able to physically dissect the organ to acquire spatial information. OBJECTIVE To develop methods to quantify and statistically compare the spatial distribution of blood flow within organs of mice. METHODS AND RESULTS We developed and validated statistical methods to compare blood flow between regions and with the same regions over time using 15-µm fluorescent microspheres. We then tested this approach by injecting fluorescent microspheres into isolated perfused mice hearts, determining the spatial location of every microsphere in the hearts, and then visualizing regional flow patterns. We demonstrated application of these statistical and visualizing methods in a coronary artery ligation model in mice. CONCLUSIONS These new methods provide tools to investigate the spatial and temporal changes in blood flow within organs of mice at a much higher spatial resolution than currently available by other methods.
Collapse
Affiliation(s)
- Melissa A Krueger
- Division of Pulmonary and Critical Care Medicine, Box 356522, University of Washington School of Medicine, Seattle, WA 98195, USA.
| | | | | |
Collapse
|
28
|
Akki A, Gupta A, Weiss RG. Magnetic resonance imaging and spectroscopy of the murine cardiovascular system. Am J Physiol Heart Circ Physiol 2013; 304:H633-48. [PMID: 23292717 DOI: 10.1152/ajpheart.00771.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Magnetic resonance imaging (MRI) has emerged as a powerful and reliable tool to noninvasively study the cardiovascular system in clinical practice. Because transgenic mouse models have assumed a critical role in cardiovascular research, technological advances in MRI have been extended to mice over the last decade. These have provided critical insights into cardiac and vascular morphology, function, and physiology/pathophysiology in many murine models of heart disease. Furthermore, magnetic resonance spectroscopy (MRS) has allowed the nondestructive study of myocardial metabolism in both isolated hearts and in intact mice. This article reviews the current techniques and important pathophysiological insights from the application of MRI/MRS technology to murine models of cardiovascular disease.
Collapse
Affiliation(s)
- Ashwin Akki
- Division of Cardiology, Department of Medicine, and Division of Magnetic Resonance Research, Department of Radiology, The Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | | | | |
Collapse
|
29
|
Troalen T, Capron T, Cozzone PJ, Bernard M, Kober F. Cine-ASL: A steady-pulsed arterial spin labeling method for myocardial perfusion mapping in mice. Part I. Experimental study. Magn Reson Med 2013; 70:1389-98. [DOI: 10.1002/mrm.24565] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 10/17/2012] [Accepted: 11/02/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Thomas Troalen
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM); UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université; Marseille France
| | - Thibaut Capron
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM); UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université; Marseille France
| | - Patrick J. Cozzone
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM); UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université; Marseille France
| | - Monique Bernard
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM); UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université; Marseille France
| | - Frank Kober
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM); UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université; Marseille France
| |
Collapse
|
30
|
Capron T, Troalen T, Cozzone PJ, Bernard M, Kober F. Cine-ASL: a steady-pulsed arterial spin labeling method for myocardial perfusion mapping in mice. Part II. Theoretical model and sensitivity optimization. Magn Reson Med 2012; 70:1399-408. [PMID: 23281063 DOI: 10.1002/mrm.24588] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 10/17/2012] [Accepted: 11/14/2012] [Indexed: 12/21/2022]
Abstract
In small rodent myocardial perfusion studies, the most widely used method is based on Look-Locker measurements of the magnetization recovery after FAIR preparation, which bears limitations regarding acquisition efficiency due to the pulsed arterial spin labeling nature of the sequence. To improve efficiency, this two-article set proposes a new steady-pulsed arterial spin labeling scheme using a cine readout incorporating one tagging pulse per heart cycle. In this part, we derive a theoretical description of the magnetization time evolution in such a scheme. The combination of steady-pulsed labeling and cine readout drives tissue magnetization into a stationary regime that explicitly depends on perfusion. In comparison with dedicated experiments on the mouse heart, the model is discussed and validated for perfusion quantification. The model predicts that in this regime, signal is independent of irregular dynamics occurring during acquisition, such as heart rate variations or arterial input function. Optimization of the sequence offers the possibility to increase the signal to noise ratio by efficient signal averaging. The sensitivity of this new method is shown to be more than three times larger than previously used techniques.
Collapse
Affiliation(s)
- Thibaut Capron
- Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université, Marseille, France
| | | | | | | | | |
Collapse
|
31
|
Campbell‐Washburn AE, Zhang H, Siow BM, Price AN, Lythgoe MF, Ordidge RJ, Thomas DL. Multislice cardiac arterial spin labeling using improved myocardial perfusion quantification with simultaneously measured blood pool input function. Magn Reson Med 2012; 70:1125-36. [DOI: 10.1002/mrm.24545] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/17/2012] [Accepted: 10/06/2012] [Indexed: 12/20/2022]
Affiliation(s)
- Adrienne E. Campbell‐Washburn
- Centre for Advanced Biomedical ImagingDivision of Medicine and Institute of Child HealthUniversity College LondonUK
- Department of Medical Physics and BioengineeringUniversity College LondonUK
| | - Hui Zhang
- Centre for Medical Image ComputingDepartment of Computer ScienceUniversity College LondonUK
| | - Bernard M. Siow
- Centre for Advanced Biomedical ImagingDivision of Medicine and Institute of Child HealthUniversity College LondonUK
- Centre for Medical Image ComputingDepartment of Computer ScienceUniversity College LondonUK
| | - Anthony N. Price
- Division of Imaging Sciences and Biomedical EngineeringKing's College LondonKing's Health PartnersSt. Thomas' HospitalLondonUK
| | - Mark F. Lythgoe
- Centre for Advanced Biomedical ImagingDivision of Medicine and Institute of Child HealthUniversity College LondonUK
| | - Roger J. Ordidge
- Centre for NeuroscienceUniversity of MelbourneMelbourneAustralia
| | - David L. Thomas
- Department of Brain Repair and RehabilitationUniversity College LondonInstitute of NeurologyQueen SquareLondonUK
| |
Collapse
|
32
|
Abeykoon S, Sargent M, Wansapura JP. Quantitative myocardial perfusion in mice based on the signal intensity of flow sensitized CMR. J Cardiovasc Magn Reson 2012; 14:73. [PMID: 23095212 PMCID: PMC3519741 DOI: 10.1186/1532-429x-14-73] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 10/11/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND In the conventional approach to arterial spin labeling in the rodent heart, the relative difference in the apparent T(1) relaxation times corresponding to selective and non-selective inversion is related to perfusion via a two compartment model of tissue. But accurate determination of T(1) in small animal hearts is difficult and prone to errors due to long scan times and high heart rates. In this study we introduce the theoretical frame work for an alternative method (SI-method) based purely on the signal intensity of slice-select and non-select inversion recovery images at a single inversion time at short repetition time. METHODS A modified Bloch equation was solved to derive perfusion as a function of signal intensity of flow sensitized segmented gradient echo acquisitions. A two compartment fast exchanging model of tissue was assumed. To test the new technique first it was implemented on a flow phantom and then it was compared with the conventional T(1) method in an in vivo study of healthy C57BL/6 mice (n=12). Finally the SI-method was used in comparison to a Late Gadolinium Enhanced (LGE) method to qualitatively and quantitatively assess perfusion deficits in an ischemia-reperfusion mouse model (n=4). RESULTS The myocardial perfusion of healthy mice obtained by the SI-method, 5.6 ± 0.5 ml/g/min, (mean ± standard deviation) was similar (p=0.38) to that obtained by the conventional method, 5.6 ± 0.3 ml/g/min. The variance in perfusion within the left ventricle was less for the SI-method than that for the conventional method (p<0.0001). The mean percentage standard deviation among repeated measures was 3.6%. The LGE regions of the ischemia reperfusion model were matched with regions of hypo-perfusion in the perfusion map. The average perfusion in the hypo perfused region among all four IR mice was 1.2 ± 0.9 ml/g/min and that of the remote region was 4.4 ± 1.2 ml/g/min. CONCLUSIONS The proposed signal intensity based ASL method with a segmented acquisition scheme allows accurate high resolution perfusion mapping in small animals. It's short scan time, high reproducibility and ease of post process makes it a robust alternative to the conventional ASL technique that relies on T(1) measurements.
Collapse
Affiliation(s)
- Sumeda Abeykoon
- Department of Physics, University of Cincinnati, Cincinnati, OH, USA
- Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital, 3333 Burnet Ave, MLC 5033, Cincinnati, OH, 45229, USA
| | - Michelle Sargent
- Howard Hughes Medical Institute, Molecular Cardiovascular Biology, Cincinnati Children Hospital, Cincinnati, OH, USA
| | - Janaka P Wansapura
- Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital, 3333 Burnet Ave, MLC 5033, Cincinnati, OH, 45229, USA
| |
Collapse
|
33
|
van Nierop BJ, Coolen BF, Dijk WJ, Hendriks AD, de Graaf L, Nicolay K, Strijkers GJ. Quantitative first-pass perfusion MRI of the mouse myocardium. Magn Reson Med 2012; 69:1735-44. [DOI: 10.1002/mrm.24424] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 06/11/2012] [Accepted: 06/27/2012] [Indexed: 01/05/2023]
|
34
|
Coolen BF, Paulis LEM, Geelen T, Nicolay K, Strijkers GJ. Contrast-enhanced MRI of murine myocardial infarction - part II. NMR IN BIOMEDICINE 2012; 25:969-984. [PMID: 22311260 DOI: 10.1002/nbm.2767] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/07/2011] [Accepted: 11/29/2011] [Indexed: 05/31/2023]
Abstract
Mouse models are increasingly used to study the pathophysiology of myocardial infarction in vivo. In this area, MRI has become the gold standard imaging modality, because it combines high spatial and temporal resolution functional imaging with a large variety of methods to generate soft tissue contrast. In addition, (target-specific) MRI contrast agents can be employed to visualize different processes in the cascade of events following myocardial infarction. Here, the MRI sequence has a decisive role in the detection sensitivity of a contrast agent. However, a straightforward translation of clinically available protocols for human cardiac imaging to mice is not feasible, because of the small size of the mouse heart and its extremely high heart rate. This has stimulated intense research in the development of cardiac MRI protocols specifically tuned to the mouse with regard to timing parameters, acquisition strategies, and ECG- and respiratory-triggering methods to find an optimal trade-off between sensitivity, scan time, and image quality. In this review, a detailed analysis is given of the pros and cons of different mouse cardiac MR imaging methodologies and their application in contrast-enhanced MRI of myocardial infarction.
Collapse
Affiliation(s)
- Bram F Coolen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, the Netherlands
| | | | | | | | | |
Collapse
|
35
|
Quantification of Myocardial Perfusion: MRI. CURRENT CARDIOVASCULAR IMAGING REPORTS 2012. [DOI: 10.1007/s12410-012-9135-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
36
|
Campbell-Washburn AE, Price AN, Wells JA, Thomas DL, Ordidge RJ, Lythgoe MF. Cardiac arterial spin labeling using segmented ECG-gated Look-Locker FAIR: Variability and repeatability in preclinical studies. Magn Reson Med 2012; 69:238-47. [DOI: 10.1002/mrm.24243] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 01/16/2012] [Accepted: 02/13/2012] [Indexed: 11/06/2022]
|
37
|
Zhang H, Qiao H, Frank RS, Huang B, Propert KJ, Margulies S, Ferrari VA, Epstein JA, Zhou R. Spin-labeling magnetic resonance imaging detects increased myocardial blood flow after endothelial cell transplantation in the infarcted heart. Circ Cardiovasc Imaging 2012; 5:210-7. [PMID: 22311739 DOI: 10.1161/circimaging.111.966317] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND We quantified absolute myocardial blood flow (MBF) using a spin-labeling MRI (SL-MRI) method after transplantation of endothelial cells (ECs) into the infarcted heart. Our aims were to study the temporal changes in MBF in response to EC transplantation and to compare regional MBF with contractile function (wall motion) and microvascular density. METHODS AND RESULTS We first validated the SL-MRI method with the standard microsphere technique in normal rats. We then induced myocardial infarction in athymic rats and injected 5 million ECs (human umbilical vein endothelial cells) suspended in Matrigel or Matrigel alone (vehicle) along the border of the blanched infarcted area. At 2 weeks after myocardial infarction, MBF averaged over the entire slice (P=0.038) and in the infarcted region (P=0.0086) was significantly higher in EC versus vehicle group; the greater MBF was accompanied by an increase of microvasculature density in the infarcted region (P=0.0105 versus vehicle). At 4 weeks after myocardial infarction, MBF in the remote region was significantly elevated in EC-treated hearts (P=0.0277); this was accompanied by increased wall motion in this region assessed by circumferential strains (P=0.0075). Intraclass correlation coefficients and Bland-Altman plot revealed a good reproducibility of the SL-MRI method. CONCLUSIONS MBF in free-breathing rats measured by SL-MRI is validated by the standard color microsphere technique. SL-MRI allows quantification of temporal changes of regional MBF in response to EC treatment. The proof-of-principle study indicates that MBF is a unique and sensitive index to evaluate EC-mediated therapy for the infarcted heart.
Collapse
Affiliation(s)
- Hualei Zhang
- Laboratories of Molecular Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
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."
Collapse
Affiliation(s)
- René M Botnar
- Division of Imaging Sciences, King's College London, London, United Kingdom
| | | |
Collapse
|
39
|
Wech T, Lemke A, Medway D, Stork LA, Lygate CA, Neubauer S, Köstler H, Schneider JE. Accelerating cine-MR imaging in mouse hearts using compressed sensing. J Magn Reson Imaging 2011; 34:1072-9. [PMID: 21932360 PMCID: PMC3261377 DOI: 10.1002/jmri.22718] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 06/20/2011] [Indexed: 12/23/2022] Open
Abstract
Purpose To combine global cardiac function imaging with compressed sensing (CS) in order to reduce scan time and to validate this technique in normal mouse hearts and in a murine model of chronic myocardial infarction. Materials and Methods To determine the maximally achievable acceleration factor, fully acquired cine data, obtained in sham and chronically infarcted (MI) mouse hearts were 2–4-fold undersampled retrospectively, followed by CS reconstruction and blinded image segmentation. Subsequently, dedicated CS sampling schemes were implemented at a preclinical 9.4 T magnetic resonance imaging (MRI) system, and 2- and 3-fold undersampled cine data were acquired in normal mouse hearts with high temporal and spatial resolution. Results The retrospective analysis demonstrated that an undersampling factor of three is feasible without impairing accuracy of cardiac functional parameters. Dedicated CS sampling schemes applied prospectively to normal mouse hearts yielded comparable left-ventricular functional parameters, and intra- and interobserver variability between fully and 3-fold undersampled data. Conclusion This study introduces and validates an alternative means to speed up experimental cine-MRI without the need for expensive hardware. J. Magn. Reson. Imaging 2011. © 2011 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Tobias Wech
- Institute of Radiology, University of Würzburg, Würzburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Schneider JE, Lanz T, Barnes H, Stork LA, Bohl S, Lygate CA, Ordidge RJ, Neubauer S. Accelerated cardiac magnetic resonance imaging in the mouse using an eight-channel array at 9.4 Tesla. Magn Reson Med 2011; 65:60-70. [PMID: 20740650 PMCID: PMC3021721 DOI: 10.1002/mrm.22605] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
MRI has become an important tool to noninvasively assess global and regional cardiac function, infarct size, or myocardial blood flow in surgically or genetically modified mouse models of human heart disease. Constraints on scan time due to sensitivity to general anesthesia in hemodynamically compromised mice frequently limit the number of parameters available in one imaging session. Parallel imaging techniques to reduce acquisition times require coil arrays, which are technically challenging to design at ultrahigh magnetic field strengths. This work validates the use of an eight-channel volume phased-array coil for cardiac MRI in mice at 9.4 T. Two- and three-dimensional sequences were combined with parallel imaging techniques and used to quantify global cardiac function, T(1)-relaxation times and infarct sizes. Furthermore, the rapid acquisition of functional cine-data allowed for the first time in mice measurement of left-ventricular peak filling and ejection rates under intravenous infusion of dobutamine. The results demonstrate that a threefold accelerated data acquisition is generally feasible without compromising the accuracy of the results. This strategy may eventually pave the way for routine, multiparametric phenotyping of mouse hearts in vivo within one imaging session of tolerable duration.
Collapse
Affiliation(s)
- Jürgen E Schneider
- British Heart Foundation Experimental MR Unit (BMRU), Department of Cardiovascular Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom.
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Vandsburger MH, Epstein FH. Emerging MRI methods in translational cardiovascular research. J Cardiovasc Transl Res 2011; 4:477-92. [PMID: 21452060 DOI: 10.1007/s12265-011-9275-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 03/15/2011] [Indexed: 12/11/2022]
Abstract
Cardiac magnetic resonance imaging (CMR) has become a reference standard modality for imaging of left ventricular (LV) structure and function and, using late gadolinium enhancement, for imaging myocardial infarction. Emerging CMR techniques enable a more comprehensive examination of the heart, making CMR an excellent tool for use in translational cardiovascular research. Specifically, emerging CMR methods have been developed to measure the extent of myocardial edema, changes in ventricular mechanics, changes in tissue composition as a result of fibrosis, and changes in myocardial perfusion as a function of both disease and infarct healing. New CMR techniques also enable the tracking of labeled cells, molecular imaging of biomarkers of disease, and changes in calcium flux in cardiomyocytes. In addition, MRI can quantify blood flow velocity and wall shear stress in large blood vessels. Almost all of these techniques can be applied in both pre-clinical and clinical settings, enabling both the techniques themselves and the knowledge gained using such techniques in pre-clinical research to be translated from the lab bench to the patient bedside.
Collapse
Affiliation(s)
- Moriel H Vandsburger
- Department of Biological Regulation, Weizmann Institute of Science, 76100, Rehovot, Israel.
| | | |
Collapse
|
42
|
Campbell AE, Price AN, Wells JA, Lythgoe MF, Ordidge RJ. Improved cardiac arterial spin labelling in the mouse heart by optimisation of acquisition and analysis. J Cardiovasc Magn Reson 2011. [PMCID: PMC3106453 DOI: 10.1186/1532-429x-13-s1-p56] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
43
|
Coolen BF, Geelen T, Paulis LEM, Nauerth A, Nicolay K, Strijkers GJ. Three-dimensional T1 mapping of the mouse heart using variable flip angle steady-state MR imaging. NMR IN BIOMEDICINE 2011; 24:154-162. [PMID: 20960583 DOI: 10.1002/nbm.1566] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 04/20/2010] [Accepted: 04/20/2010] [Indexed: 05/28/2023]
Abstract
Cardiac MR T(1) mapping is a promising quantitative imaging tool for the diagnosis and evaluation of cardiomyopathy. Here, we present a new preclinical cardiac MRI method enabling three-dimensional T(1) mapping of the mouse heart. The method is based on a variable flip angle analysis of steady-state MR imaging data. A retrospectively triggered three-dimensional FLASH (fast low-angle shot) sequence (3D IntraGate) enables a constant repetition time and maintains steady-state conditions. 3D T(1) mapping of the complete mouse heart could be achieved in 20 min. High-quality, bright-blood T(1) maps were obtained with homogeneous T(1) values (1764 ± 172 ms) throughout the myocardium. The repeatability coefficient of R(1) (1/T(1) ) in a specific region of the mouse heart was between 0.14 and 0.20 s(-1) , depending on the number of flip angles. The feasibility for detecting regional differences in ΔR(1) was shown with pre- and post-contrast T(1) mapping in mice with surgically induced myocardial infarction, for which ΔR(1) values up to 0.83 s(-1) were found in the infarct zone. The sequence was also investigated in black-blood mode, which, interestingly, showed a strong decrease in the apparent mean T(1) of healthy myocardium (905 ± 110 ms). This study shows that 3D T(1) mapping in the mouse heart is feasible and can be used to monitor regional changes in myocardial T(1), particularly in relation to pathology and in contrast-enhanced experiments to estimate local concentrations of (targeted) contrast agent.
Collapse
Affiliation(s)
- Bram F Coolen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
| | | | | | | | | | | |
Collapse
|
44
|
Price AN, Cheung KK, Cleary JO, Campbell AE, Riegler J, Lythgoe MF. Cardiovascular magnetic resonance imaging in experimental models. Open Cardiovasc Med J 2010; 4:278-92. [PMID: 21331311 PMCID: PMC3040459 DOI: 10.2174/1874192401004010278] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 09/27/2010] [Accepted: 10/04/2010] [Indexed: 12/19/2022] Open
Abstract
Cardiovascular magnetic resonance (CMR) imaging is the modality of choice for clinical studies of the heart and vasculature, offering detailed images of both structure and function with high temporal resolution. Small animals are increasingly used for genetic and translational research, in conjunction with models of common pathologies such as myocardial infarction. In all cases, effective methods for characterising a wide range of functional and anatomical parameters are crucial for robust studies. CMR is the gold-standard for the non-invasive examination of these models, although physiological differences, such as rapid heart rate, make this a greater challenge than conventional clinical imaging. However, with the help of specialised magnetic resonance (MR) systems, novel gating strategies and optimised pulse sequences, high-quality images can be obtained in these animals despite their small size. In this review, we provide an overview of the principal CMR techniques for small animals for example cine, angiography and perfusion imaging, which can provide measures such as ejection fraction, vessel anatomy and local blood flow, respectively. In combination with MR contrast agents, regional dysfunction in the heart can also be identified and assessed. We also discuss optimal methods for analysing CMR data, particularly the use of semi-automated tools for parameter measurement to reduce analysis time. Finally, we describe current and emerging methods for imaging the developing heart, aiding characterisation of congenital cardiovascular defects. Advanced small animal CMR now offers an unparalleled range of cardiovascular assessments. Employing these methods should allow new insights into the structural, functional and molecular basis of the cardiovascular system.
Collapse
Affiliation(s)
- Anthony N Price
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, UK
| | | | | | | | | | | |
Collapse
|
45
|
Coolen BF, Moonen RPM, Paulis LEM, Geelen T, Nicolay K, Strijkers GJ. Mouse myocardial first-pass perfusion MR imaging. Magn Reson Med 2010; 64:1658-63. [DOI: 10.1002/mrm.22588] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
46
|
Vandsburger MH, Janiczek RL, Xu Y, French BA, Meyer CH, Kramer CM, Epstein FH. Improved arterial spin labeling after myocardial infarction in mice using cardiac and respiratory gated look-locker imaging with fuzzy C-means clustering. Magn Reson Med 2010; 63:648-57. [PMID: 20187175 DOI: 10.1002/mrm.22280] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Experimental myocardial infarction (MI) in mice is an important disease model, in part due to the ability to study genetic manipulations. MRI has been used to assess cardiac structural and functional changes after MI in mice, but changes in myocardial perfusion after acute MI have not previously been examined. Arterial spin labeling noninvasively measures perfusion but is sensitive to respiratory motion and heart rate variability and is difficult to apply after acute MI in mice. To account for these factors, a cardiorespiratory-gated arterial spin labeling sequence using a fuzzy C-means algorithm to retrospectively reconstruct images was developed. Using this method, myocardial perfusion was measured in remote and infarcted regions at 1, 7, 14, and 28 days post-MI. Baseline perfusion was 4.9 +/- 0.5 mL/g min and 1 day post-MI decreased to 0.9 +/- 0.8 mL/g min in infarcted myocardium (P < 0.05 versus baseline) while remaining at 5.2 +/- 0.8 mL/g min in remote myocardium. During the subsequent 28 days, perfusion in the remote zone remained unchanged, while a partial recovery of perfusion in the infarct zone was seen. This technique, when applied to genetically engineered mice, will allow for the investigation of the roles of specific genes in myocardial perfusion during infarct healing.
Collapse
Affiliation(s)
- Moriel H Vandsburger
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA
| | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
UNLABELLED The ability to trace or identify specific molecules within a specific anatomic location provides insight into metabolic pathways, tissue components, and tracing of solute transport mechanisms. With the increasing use of small animals for research, such imaging must have sufficiently high spatial resolution to allow anatomic localization as well as sufficient specificity and sensitivity to provide an accurate description of the molecular distribution and concentration. METHODS Imaging methods based on electromagnetic radiation, such as PET, SPECT, MRI, and CT, are increasingly applicable because of recent advances in novel scanner hardware and image reconstruction software and the availability of novel molecules that have enhanced sensitivity in these methodologies. RESULTS Small-animal PET has been advanced by the development of detector arrays that provide higher resolution and positron-emitting elements that allow new molecular tracers to be labeled. Micro-MRI has been improved in terms of spatial resolution and sensitivity through increased magnet field strength and the development of special-purpose coils and associated scan protocols. Of particular interest is the associated ability to image local mechanical function and solute transport processes, which can be directly related to the molecular information. This ability is further strengthened by the synergistic integration of PET with MRI. Micro-SPECT has been improved through the use of coded aperture imaging approaches as well as image reconstruction algorithms that can better deal with the photon-limited scan data. The limited spatial resolution can be partially overcome by integrating SPECT with CT. Micro-CT by itself provides exquisite spatial resolution of anatomy, but recent developments in high-spatial-resolution photon counting and spectrally sensitive imaging arrays, combined with x-ray optical devices, hold promise for actual molecular identification by virtue of the chemical bond lengths of molecules, especially biopolymers. CONCLUSION Given the increasing use of small animals for evaluating new clinical imaging techniques and providing more insight into pathophysiologic phenomena as well as the availability of improved detection systems, scanning protocols, and associated software, the sensitivity and specificity of molecular imaging are increasing.
Collapse
Affiliation(s)
| | | | - Ciprian Catana
- Massachusetts General Hospital and Harvard Medical School, Charlestown MA, U.S.A
| | | | - Erik L. Ritman
- Mayo Clinic College of Medicine, Dept. Physiology and Biomedical Engineering 200 First Street SW Rochester, MN 55905 U.S.A. Phone: 507.2551.1939 Fax: 507.255.1935
| |
Collapse
|
48
|
Kramer CM, Sinusas AJ, Sosnovik DE, French BA, Bengel FM. Multimodality imaging of myocardial injury and remodeling. J Nucl Med 2010; 51 Suppl 1:107S-121S. [PMID: 20395347 DOI: 10.2967/jnumed.109.068221] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Advances in cardiovascular molecular imaging have come at a rapid pace over the last several years. Multiple approaches have been taken to better understand the structural, molecular, and cellular events that underlie the progression from myocardial injury to myocardial infarction (MI) and, ultimately, to congestive heart failure. Multimodality molecular imaging including SPECT, PET, cardiac MRI, and optical approaches is offering new insights into the pathophysiology of MI and left ventricular remodeling in small-animal models. Targets that are being probed include, among others, angiotensin receptors, matrix metalloproteinases, integrins, apoptosis, macrophages, and sympathetic innervation. It is only a matter of time before these advances are applied in the clinical setting to improve post-MI prognostication and identify appropriate therapies in patients to prevent the onset of congestive heart failure.
Collapse
Affiliation(s)
- Christopher M Kramer
- Departments of Medicine and Radiology, University of Virginia Health System, 1215 Lee St., Box 800170, Charlottesville, VA 22908, USA.
| | | | | | | | | |
Collapse
|
49
|
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.
Collapse
Affiliation(s)
- Marcus R Makowski
- Division of Imaging Sciences, King's College London, 4th Floor, Lambeth Wing, St Thomas' Hospital, London SE1 7EH, UK.
| | | | | | | |
Collapse
|
50
|
McCommis KS, Goldstein TA, Abendschein DR, Misselwitz B, Pilgram T, Gropler RJ, Zheng J. Roles of myocardial blood volume and flow in coronary artery disease: an experimental MRI study at rest and during hyperemia. Eur Radiol 2010; 20:2005-12. [PMID: 20182731 DOI: 10.1007/s00330-010-1740-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 12/22/2009] [Accepted: 01/07/2010] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To validate fast perfusion mapping techniques in a setting of coronary artery stenosis, and to further assess the relationship of absolute myocardial blood volume (MBV) and blood flow (MBF) to global myocardial oxygen demand. METHODS A group of 27 mongrel dogs were divided into 10 controls and 17 with acute coronary stenosis. On 1.5-T MRI, first-pass perfusion imaging with a bolus injection of a blood-pool contrast agent was performed to determine myocardial perfusion both at rest and during either dipyridamole-induced vasodilation or dobutamine-induced stress. Regional values of MBF and MBV were quantified by using a fast mapping technique. Color microspheres and (99m)Tc-labeled red blood cells were injected to obtain respective gold standards. RESULTS Microsphere-measured MBF and (99m)Tc-measured MBV reference values correlated well with the MR results. Given the same changes in MBF, changes in MBV are twofold greater with dobutamine than with dipyridamole. Under dobutamine stress, MBV shows better association with total myocardial oxygen demand than MBF. Coronary stenosis progressively reduced this association in the presence of increased stenosis severity. CONCLUSIONS MR first-pass perfusion can rapidly estimate regional MBF and MBV. Absolute quantification of MBV may add additional information on stenosis severity and myocardial viability compared with standard qualitative clinical evaluations of myocardial perfusion.
Collapse
Affiliation(s)
- Kyle S McCommis
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA.
| | | | | | | | | | | | | |
Collapse
|