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Molecular MR-Imaging in Thromboembolic Stroke Using a Fibrin-Specific Contrast Agent in Patients at 3 Tesla. Clin Neuroradiol 2021; 31:925-931. [PMID: 34236442 DOI: 10.1007/s00062-021-01052-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/05/2021] [Indexed: 10/20/2022]
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2
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Abstract
Molecular magnetic resonance (MR) imaging utilizes molecular probes to provide added biochemical or cellular information to what can already be achieved with anatomical and functional MR imaging. This review provides an overview of molecular MR and focuses specifically on molecular MR contrast agents that provide contrast by shortening the T1 time. We describe the requirements for a successful molecular MR contrast agent and the challenges for clinical translation. The review highlights work from the last 5 years and places an emphasis on new contrast agents that have been validated in multiple preclinical models. Applications of molecular MR include imaging of inflammation, fibrosis, fibrogenesis, thromboembolic disease, and cancers. Molecular MR is positioned to move beyond detection of disease to the quantitative staging of disease and measurement of treatment response.
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Affiliation(s)
| | | | - Peter Caravan
- The Institute for Innovation in Imaging, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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3
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Salarian M, Ibhagui OY, Yang JJ. Molecular imaging of extracellular matrix proteins with targeted probes using magnetic resonance imaging. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2020; 12:e1622. [PMID: 32126587 DOI: 10.1002/wnan.1622] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 01/04/2020] [Accepted: 02/04/2020] [Indexed: 12/14/2022]
Abstract
The extracellular matrix (ECM) consists of proteins and carbohydrates that supports different biological structures and processes such as tissue development, elasticity, and preservation of organ structure. Diseases involving inflammation, fibrosis, tumor invasion, and injury are all attributed to the transition of the ECM from homeostasis to remodeling, which can significantly change the biochemical and biomechanical features of ECM components. While contrast agents have played an indispensable role in facilitating clinical diagnosis of diseases using magnetic resonance imaging (MRI), there is a strong need to develop novel biomarker-targeted imaging probes for in vivo visualization of biological processes and pathological alterations at a cellular and molecular level, for both early diagnosis and monitoring drug treatment. Herein, we will first review the pathological accumulation and characterization of ECM proteins recognized as important molecular features of diseases. Developments in MRI probes targeting ECM proteins such as collagen, fibronectin, and elastin via conjugation of existing contrast agents to targeting moieties and their applications to various diseases, are also reviewed. We have also reviewed our progress in the development of collagen-targeted protein MRI contrast agent with significant improvement in relaxivity and metal binding specificity, and their applications in early detection of fibrosis and metastatic cancer. This article is categorized under: Diagnostic Tools > in vivo Nanodiagnostics and Imaging Biology-Inspired Nanomaterials > Peptide-Based Structures Biology-Inspired Nanomaterials > Protein and Virus-Based Structures.
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Affiliation(s)
- Mani Salarian
- Department of Chemistry, Georgia State University, Atlanta, Georgia
| | | | - Jenny J Yang
- Department of Chemistry, Georgia State University, Atlanta, Georgia.,Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia
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4
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Lanza GM, Cui G, Schmieder AH, Zhang H, Allen JS, Scott MJ, Williams T, Yang X. An unmet clinical need: The history of thrombus imaging. J Nucl Cardiol 2019; 26:986-997. [PMID: 28608182 PMCID: PMC5741521 DOI: 10.1007/s12350-017-0942-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 05/24/2017] [Indexed: 11/24/2022]
Abstract
Robust thrombus imaging is an unresolved clinical unmet need dating back to the mid 1970s. While early molecular imaging approaches began with nuclear SPECT imaging, contrast agents for virtually all biomedical imaging modalities have been demonstrated in vivo with unique strengths and common weaknesses. Two primary molecular imaging targets have been pursued for thrombus imaging: platelets and fibrin. Some common issues noted over 40 years ago persist today. Acute thrombus is readily imaged with all probes and modalities, but aged thrombus remains a challenge. Similarly, anti-coagulation continues to interfere with and often negate thrombus imaging efficacy, but heparin is clinically required in patients suspected of pulmonary embolism, deep venous thrombosis or coronary ruptured plaque prior to confirmatory diagnostic studies have been executed and interpreted. These fundamental issues can be overcome, but an innovative departure from the prior approaches will be needed.
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Affiliation(s)
- Gregory M Lanza
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA.
| | - Grace Cui
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA
| | - Anne H Schmieder
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA
| | - Huiying Zhang
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA
| | - John S Allen
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA
| | - Michael J Scott
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA
| | - Todd Williams
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA
| | - Xiaoxia Yang
- Department of Medicine, Division of Cardiology, Washington University Medical School, St. Louis, MO, 63108, USA
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5
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Désogère P, Montesi SB, Caravan P. Molecular Probes for Imaging Fibrosis and Fibrogenesis. Chemistry 2019; 25:1128-1141. [PMID: 30014529 PMCID: PMC6542638 DOI: 10.1002/chem.201801578] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Indexed: 12/26/2022]
Abstract
Fibrosis, or the accumulation of extracellular matrix molecules that make up scar tissue, is a common result of chronic tissue injury. Advances in the clinical management of fibrotic diseases have been hampered by the low sensitivity and specificity of noninvasive early diagnostic options, lack of surrogate end points for use in clinical trials, and a paucity of noninvasive tools to assess fibrotic disease activity longitudinally. Hence, the development of new methods to image fibrosis and fibrogenesis is a large unmet clinical need. Herein, an overview of recent and selected molecular probes for imaging of fibrosis and fibrogenesis by magnetic resonance imaging, positron emission tomography, and single photon emission computed tomography is provided.
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Affiliation(s)
- Pauline Désogère
- The Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
- The Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, 02128, USA
| | - Sydney B Montesi
- Division of Pulmonary and Critical Care, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Peter Caravan
- The Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
- The Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, 02128, USA
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6
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Rahaghi FN, Minhas JK, Heresi GA. Diagnosis of Deep Venous Thrombosis and Pulmonary Embolism: New Imaging Tools and Modalities. Clin Chest Med 2018; 39:493-504. [PMID: 30122174 PMCID: PMC6317734 DOI: 10.1016/j.ccm.2018.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Imaging continues to be the modality of choice for the diagnosis of venous thromboembolic disease, particularly when incorporated into diagnostic algorithms. Improvement in imaging techniques as well as new imaging modalities and processing methods have improved diagnostic accuracy and additionally are being leveraged in prognostication and decision making for choice of intervention. In this article, we review the role of imaging in diagnosis and prognostication of venous thromboembolism. We also discuss emerging imaging approaches that may in the near future find clinical usefulness in improving diagnosis and prognostication as well as differentiating disease phenotypes.
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Affiliation(s)
- Farbod N. Rahaghi
- Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School. 15 Francis Street, Boston MA 02115, ; Phone: 617-632-6770
| | - Jasleen K. Minhas
- Department of Medicine, North Shore Medical Center, 81 highland Ave Salem MA 10970, Phone: 978-354-4801
| | - Gustavo A. Heresi
- Respiratory Institute, Cleveland Clinic, Mail code A90, 9500 Euclid Ave, OH 44195, Phone: 216-636-5327
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7
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Bode C, von zur Mühlen C. MRI, the technology for imaging of thrombi and inflammation. Hamostaseologie 2017; 35:252-62. [DOI: 10.5482/hamo-14-11-0061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/13/2015] [Indexed: 11/05/2022] Open
Abstract
SummaryAtherosclerosis and its sequelae have a major impact on morbidity and mortality. The rupture of an inflamed atherosclerotic plaque is a crucial event, since it can result in acute thrombotic closure of an arterial vessel, resulting e. g. in myocardial infarction or stroke. Not only detection of early plaque rupture with imminent closure is therefore of clinical interest, but also timely detection of vascular inflammation and atherosclerotic plaque progression. However, plaque inflammation or even plaque rupture without vessel occlusion is not reliably detectable by current imaging techniques. Coronary angiography is the gold standard for evaluation of the coronary vessels, but only allows visualization of the vessel lumen without characterizing the important pathophysiology of the vessel wall. Therefore, highly inflamed and rupture prone plaques can be missed, or appear as a minor vessel narrowing. Although currently available techniques such as intravascular ultrasound or optical coherence tomography allow a further characterization of atherosclerotic plaques, it would be desirable to detect plaque inflammation, early plaque rupture or vascular thrombosis by non-invasive techniques such as magnetic resonance imaging (MRI), since they could allow early identification of patients at risk or triage of symptomatic patients.In this manuscript, different strategies for detection of vascular inflammation, plaque-rupture and thrombosis by MRI will be discussed, with a special focus on molecular imaging contrast agents.
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8
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Abstract
The development of new methods to image the onset and progression of thrombosis is an unmet need. Non-invasive molecular imaging techniques targeting specific key structures involved in the formation of thrombosis have demonstrated the ability to detect thrombus in different disease state models and in patients. Due to its high concentration in the thrombus and its essential role in thrombus formation, the detection of fibrin is an attractive strategy for identification of thrombosis. Herein we provide an overview of recent and selected fibrin-targeted probes for molecular imaging of thrombosis by magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), and optical techniques. Emphasis is placed on work that our lab has explored over the last 15 years that has resulted in the progression of the fibrin-binding PET probe [64Cu]FBP8 from preclinical studies into human trials.
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Affiliation(s)
- Bruno L Oliveira
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK.
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9
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van Mourik TR, Claesener M, Nicolay K, Grüll H. Development of a novel, fibrin-specific PET tracer. J Labelled Comp Radiopharm 2017; 60:286-293. [DOI: 10.1002/jlcr.3501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 02/02/2017] [Accepted: 03/15/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Tiemen R. van Mourik
- Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven The Netherlands
| | - Michael Claesener
- Department of Nuclear Medicine; University of Münster; Münster Germany
| | - Klaas Nicolay
- Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven The Netherlands
| | - Holger Grüll
- Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven The Netherlands
- Department of Oncology Solutions; Philips Research; Eindhoven The Netherlands
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10
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Shea BS, Probst CK, Brazee PL, Rotile NJ, Blasi F, Weinreb PH, Black KE, Sosnovik DE, Van Cott EM, Violette SM, Caravan P, Tager AM. Uncoupling of the profibrotic and hemostatic effects of thrombin in lung fibrosis. JCI Insight 2017; 2:86608. [PMID: 28469072 PMCID: PMC5414562 DOI: 10.1172/jci.insight.86608] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 03/21/2017] [Indexed: 02/06/2023] Open
Abstract
Fibrotic lung disease, most notably idiopathic pulmonary fibrosis (IPF), is thought to result from aberrant wound-healing responses to repetitive lung injury. Increased vascular permeability is a cardinal response to tissue injury, but whether it is mechanistically linked to lung fibrosis is unknown. We previously described a model in which exaggeration of vascular leak after lung injury shifts the outcome of wound-healing responses from normal repair to pathological fibrosis. Here we report that the fibrosis produced in this model is highly dependent on thrombin activity and its downstream signaling pathways. Direct thrombin inhibition with dabigatran significantly inhibited protease-activated receptor-1 (PAR1) activation, integrin αvβ6 induction, TGF-β activation, and the development of pulmonary fibrosis in this vascular leak-dependent model. We used a potentially novel imaging method - ultashort echo time (UTE) lung magnetic resonance imaging (MRI) with the gadolinium-based, fibrin-specific probe EP-2104R - to directly visualize fibrin accumulation in injured mouse lungs, and to correlate the antifibrotic effects of dabigatran with attenuation of fibrin deposition. We found that inhibition of the profibrotic effects of thrombin can be uncoupled from inhibition of hemostasis, as therapeutic anticoagulation with warfarin failed to downregulate the PAR1/αvβ6/TGF-β axis or significantly protect against fibrosis. These findings have direct and important clinical implications, given recent findings that warfarin treatment is not beneficial in IPF, and the clinical availability of direct thrombin inhibitors that our data suggest could benefit these patients.
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Affiliation(s)
- Barry S. Shea
- Division of Pulmonary, Critical Care and Sleep Medicine, Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island, USA
- Division of Pulmonary and Critical Care Medicine and Center for Immunology and Inflammatory Diseases
| | - Clemens K. Probst
- Division of Pulmonary and Critical Care Medicine and Center for Immunology and Inflammatory Diseases
| | - Patricia L. Brazee
- Division of Pulmonary and Critical Care Medicine and Center for Immunology and Inflammatory Diseases
| | | | - Francesco Blasi
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology
| | | | - Katharine E. Black
- Division of Pulmonary and Critical Care Medicine and Center for Immunology and Inflammatory Diseases
| | - David E. Sosnovik
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology
| | - Elizabeth M. Van Cott
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | | | - Peter Caravan
- A. A. Martinos Center for Biomedical Imaging, Department of Radiology
| | - Andrew M. Tager
- Division of Pulmonary and Critical Care Medicine and Center for Immunology and Inflammatory Diseases
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11
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Molecular Imaging of Activated Platelets Allows the Detection of Pulmonary Embolism with Magnetic Resonance Imaging. Sci Rep 2016; 6:25044. [PMID: 27138487 PMCID: PMC4853725 DOI: 10.1038/srep25044] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 04/08/2016] [Indexed: 01/04/2023] Open
Abstract
Early and reliable detection of pulmonary embolism (PE) is critical for improving patient morbidity and mortality. The desire for low-threshold screening for pulmonary embolism is contradicted by unfavorable radiation of currently used computed tomography or nuclear techniques, while standard magnetic resonance imaging still struggles to provide sufficient diagnostic sensitivity in the lung. In this study we evaluate a molecular-targeted contrast agent against activated platelets for non-invasive detection of murine pulmonary thromboembolism using magnetic resonance imaging. By intravenous injection of human thrombin, pulmonary thromboembolism were consistently induced as confirmed by immunohistochemistry of the lung. Magnetic resonance imaging after thrombin injection showed local tissue edema in weighted images which co-localized with the histological presence of pulmonary thromboembolism. Furthermore, injection of a functionalized contrast agent targeting activated platelets provided sensitive evidence of focal accumulation of activated platelets within the edematous area, which, ex vivo, correlated well with the size of the pulmonary embolism. In summary, we here show delivery and specific binding of a functionalized molecular contrast agent against activated platelets for targeting pulmonary thromboembolism. Going forward, molecular imaging may provide new opportunities to increase sensitivity of magnetic resonance imaging for detection of pulmonary embolism.
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12
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Vidmar J, Serša I, Kralj E, Popovič P. Unsuccessful percutaneous mechanical thrombectomy in fibrin-rich high-risk pulmonary thromboembolism. Thromb J 2015; 13:30. [PMID: 26379477 PMCID: PMC4571107 DOI: 10.1186/s12959-015-0060-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/09/2015] [Indexed: 12/02/2022] Open
Abstract
Background We report a case of unsuccessful percutaneous mechanical thrombectomy in treatment of a high-risk pulmonary embolism (PE). Pulmonary thromboemboli are commonly expected as a homogenous mass, rich with red blood cell content, which respond well to percutaneous mechanical thrombectomy (PMT). Catheter-based approach or surgical embolectomy are two treatment options that are usually considered for treatment of high-risk PE when the thrombolytic therapy fails or it is contraindicated due to a patient’s persisting hemodynamic compromise. Currently, selection criteria for PE treatment options are based mostly on the assessment of patient’s history. The aim of this report is to highlight a possible treatment complication in PMT of structurally heterogeneous thrombotic mass due to PMT inadequacy. Case presentation A 32 year-old male with polytrauma was admitted to an intensive care unit after a right-sided nephrectomy and evacuation of retroperitoneal hematoma. The patient initial haemostatic disorder was improved by administration of blood preparations, an anti-fibrinolytic agent and concentrates of fibrinogen. On the third day he presented sudden onset of hemodynamic instability and was incapable of standard CTA diagnostic procedure. Urgent and relevant investigations including transthoracic and transesophageal echocardiogram confirmed a high-risk PE. PMT was performed due to contraindications for systemic thrombolysis. Long-term PMT was attempted using aspiration with several devices. No major improvement was achieved in any of the treatments and the patient died. Autopsy confirmed a large heterogeneous thrombotic mass in the pulmonary trunk folding to the right main artery. Additional histological analysis revealed a high fibrin-rich content in the peripheral surroundings of the thrombus. Conclusion In the case, it was confirmed that the outcome of PMT was directly influenced by mechanical and histological features of the thromboembolus in high-risk PE. Formation of a rather complex thromboembolus in high-risk PE favors surgical embolectomy as the only life-saving treatment option. Current diagnostic imaging techniques do not enable precise assessment of thrombi structure and are therefore unable to identify patients who might benefit from PMT or open surgical embolectomy. Surgical backup treatment should be considered if there are no contraindications in the event of a failed catheter intervention.
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Affiliation(s)
- Jernej Vidmar
- Institute of Physiology, Medical Faculty, University of Ljubljana, Zaloska cesta 4, 1000 Ljubljana, Slovenia ; Jožef Stefan Institute, Ljubljana, Slovenia
| | - Igor Serša
- Jožef Stefan Institute, Ljubljana, Slovenia
| | - Eduard Kralj
- Institute of Forensic Medicine, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Peter Popovič
- Institue of Radiology, University Medical Centre Ljubljana, Ljubljana, Slovenia
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13
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Starmans LWE, van Mourik T, Rossin R, Verel I, Nicolay K, Grüll H. Noninvasive Visualization of Tumoral Fibrin Deposition Using a Peptidic Fibrin-Binding Single Photon Emission Computed Tomography Tracer. Mol Pharm 2015; 12:1921-8. [DOI: 10.1021/mp500673u] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Lucas W. E. Starmans
- Department
of Biomedical Engineering, Eindhoven University of Technology, High Tech
Campus 11, 5656 AE, Eindhoven, The Netherlands
| | - Tiemen van Mourik
- Department
of Biomedical Engineering, Eindhoven University of Technology, High Tech
Campus 11, 5656 AE, Eindhoven, The Netherlands
| | - Raffaella Rossin
- Oncology Solutions,
Philips Research, High Tech Campus
11, 5656 AE, Eindhoven, The Netherlands
| | - Iris Verel
- Oncology Solutions,
Philips Research, High Tech Campus
11, 5656 AE, Eindhoven, The Netherlands
| | - Klaas Nicolay
- Department
of Biomedical Engineering, Eindhoven University of Technology, High Tech
Campus 11, 5656 AE, Eindhoven, The Netherlands
| | - Holger Grüll
- Department
of Biomedical Engineering, Eindhoven University of Technology, High Tech
Campus 11, 5656 AE, Eindhoven, The Netherlands
- Oncology Solutions,
Philips Research, High Tech Campus
11, 5656 AE, Eindhoven, The Netherlands
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14
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Noninvasive Imaging of Early Venous Thrombosis by
19
F Magnetic Resonance Imaging With Targeted Perfluorocarbon Nanoemulsions. Circulation 2015; 131:1405-14. [DOI: 10.1161/circulationaha.114.010962] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Accepted: 02/13/2015] [Indexed: 11/16/2022]
Abstract
Background—
Noninvasive detection of deep venous thrombi and subsequent pulmonary thromboembolism is a serious medical challenge, since both incidences are difficult to identify by conventional ultrasound techniques.
Methods and Results—
Here, we report a novel technique for the sensitive and specific identification of developing thrombi using background-free
19
F magnetic resonance imaging, together with α2-antiplasmin peptide (α2
AP
)–targeted perfluorocarbon nanoemulsions (PFCs) as contrast agent, which is cross-linked to fibrin by active factor XIII. Ligand functionality was ensured by mild coupling conditions using the sterol-based postinsertion technique. Developing thrombi with a diameter <0.8 mm could be visualized unequivocally in the murine inferior vena cava as hot spots in vivo by simultaneous acquisition of anatomic matching
1
H and
19
F magnetic resonance images at 9.4 T with both excellent signal-to-noise and contrast-to-noise ratios (71±22 and 17±5, respectively). Furthermore, α2
AP
-PFCs could be successfully applied for the diagnosis of experimentally induced pulmonary thromboembolism. In line with the reported half-life of factor XIIIa, application of α2
AP
-PFCs >60 minutes after thrombus induction no longer resulted in detectable
19
F magnetic resonance imaging signals. Corresponding results were obtained in ex vivo generated human clots. Thus, α2
AP
-PFCs can visualize freshly developed thrombi that might still be susceptible to pharmacological intervention.
Conclusions—
Our results demonstrate that
1
H/
19
F magnetic resonance imaging, together with α2
AP
-PFCs, is a sensitive, noninvasive technique for the diagnosis of acute deep venous thrombi and pulmonary thromboemboli. Furthermore, ligand coupling by the sterol-based postinsertion technique represents a unique platform for the specific targeting of PFCs for in vivo
19
F magnetic resonance imaging.
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15
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Starmans LWE, van Duijnhoven SMJ, Rossin R, Berben M, Aime S, Daemen MJAP, Nicolay K, Grüll H. Evaluation of 111In-Labeled EPep and FibPep as Tracers for Fibrin SPECT Imaging. Mol Pharm 2013; 10:4309-21. [DOI: 10.1021/mp400406x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Lucas W. E. Starmans
- Department
of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Center for Imaging Research and Education (CIRE), Eindhoven, The Netherlands
| | - Sander M. J. van Duijnhoven
- Department
of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Center for Imaging Research and Education (CIRE), Eindhoven, The Netherlands
| | - Raffaella Rossin
- Center for Imaging Research and Education (CIRE), Eindhoven, The Netherlands
- Department
of Minimally Invasive Healthcare, Philips Research, Eindhoven, The Netherlands
| | - Monique Berben
- Center for Imaging Research and Education (CIRE), Eindhoven, The Netherlands
- Department
of Minimally Invasive Healthcare, Philips Research, Eindhoven, The Netherlands
| | - Silvio Aime
- Department
of Chemistry IFM and Molecular Imaging Center, University of Torino, Torino, Italy
| | - Mat J. A. P. Daemen
- Department
of Pathology, Academical Medical Center, Amsterdam, The Netherlands
| | - Klaas Nicolay
- Department
of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Center for Imaging Research and Education (CIRE), Eindhoven, The Netherlands
| | - Holger Grüll
- Department
of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Center for Imaging Research and Education (CIRE), Eindhoven, The Netherlands
- Department
of Minimally Invasive Healthcare, Philips Research, Eindhoven, The Netherlands
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Abstract
RATIONALE AND OBJECTIVES Fibrin deposition has been indicated within the stroma of a majority of solid tumors. Here we assess the feasibility of using the established fibrin-specific probe EP-2104R for noninvasive imaging of fibrin in the context of breast cancer. METHODS EP-2104R, untargeted gadopentetate dimeglumine (Gd-DTPA), and a newly synthesized nonfibrin binding control linear peptide (CLP) were compared using steady-state and dynamic contrast-enhanced magnetic resonance imaging in a breast cancer xenograft mouse model at 9.4 T. RESULTS EP-2104R transiently enhanced both tumor core and tumor periphery, but only the enhancement in the tumor periphery persisted even 90 minutes after EP-2104R administration. However, untargeted Gd-DTPA and CLP are not retained in the tumor periphery. The half-life of EP-2104R in the tumor periphery (103 ± 18 minutes) is significantly longer (P < 0.05) than that of either Gd-DTPA (29.6 ± 2.4 minutes) or CLP (42.4 ± 1.5 minutes), but the rate of clearance is similar for all the 3 probes from the tumor core. The presence of high concentrations of fibrin in the tumor periphery was corroborated using immunohistochemistry with a fibrin-specific antibody. CONCLUSIONS The persistent enhancement observed in the tumor periphery with EP-2104R is likely a result of its fibrin-specific binding rather than its size and demonstrates the feasibility of EP-2104R for molecular imaging of fibrin in tumor stroma.
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17
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Ciesienski KL, Yang Y, Ay I, Chonde DB, Loving GS, Rietz TA, Catana C, Caravan P. Fibrin-targeted PET probes for the detection of thrombi. Mol Pharm 2013; 10:1100-10. [PMID: 23327109 DOI: 10.1021/mp300610s] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
There is an ongoing effort to develop better methods for noninvasive detection and characterization of thrombi. Here we describe the synthesis and evaluation of three new fibrin-targeted positron emission tomography (PET) probes (FBP1, FBP2, FBP3). Three fibrin-specific peptides were conjugated as 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-monoamides at the C- and N-termini and chelated with (64)CuCl2. Probes were prepared with a specific activity ranging from 10 to 130 μCi/nmol. Both the peptides and the probes exhibited nanomolar dissociation constants (Kd) for the soluble fibrin fragment DD(E), although the Cu-DOTA derivatization resulted in a 2-3 fold loss in affinity relative to the parent peptide. Biodistribution and imaging studies were performed in a rat model of carotid artery thrombosis. For FBP1 and FBP2 at 120 min post injection, the vessel containing the thrombus showed the highest concentration of radioactivity after the excretory organs, that is, the liver and kidneys. This was confirmed ex vivo by autoradiography, which showed >4-fold activity in the thrombus-containing artery compared to the contralateral artery. FBP3 showed much lower thrombus uptake, and the difference was traced to greater metabolism of this probe. Hybrid MR-PET imaging with FBP1 or FBP2 confirmed that these probes were effective for the detection of an arterial thrombus in this rat model. A thrombus was visible on PET images as a region of high activity that corresponded to a region of arterial occlusion identified by simultaneous MR angiography. FBP1 and FBP2 represent promising new probes for the molecular imaging of thrombi.
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Affiliation(s)
- Katie L Ciesienski
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School , 149 Thirteenth Street, Suite 2301, Charlestown, Massachusetts 02129, USA
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Phinikaridou A, Andia ME, Shah AM, Botnar RM. Advances in molecular imaging of atherosclerosis and myocardial infarction: shedding new light on in vivo cardiovascular biology. Am J Physiol Heart Circ Physiol 2012; 303:H1397-410. [PMID: 23064836 DOI: 10.1152/ajpheart.00583.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Molecular imaging of the cardiovascular system heavily relies on the development of new imaging probes and technologies to facilitate visualization of biological processes underlying or preceding disease. Molecular imaging is a highly active research discipline that has seen tremendous growth over the past decade. It has broadened our understanding of oncologic, neurologic, and cardiovascular diseases by providing new insights into the in vivo biology of disease progression and therapeutic interventions. As it allows for the longitudinal evaluation of biological processes, it is ideally suited for monitoring treatment response. In this review, we will concentrate on the major accomplishments and advances in the field of molecular imaging of atherosclerosis and myocardial infarction with a special focus on magnetic resonance imaging.
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Affiliation(s)
- Alkystis Phinikaridou
- Division of Imaging Science and Biomedical Engineering, King's College London, United Kingdom.
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Vithanarachchi SM, Allen MJ. Strategies for Target-Specific Contrast Agents for Magnetic Resonance Imaging. ACTA ACUST UNITED AC 2012; 1:12-25. [PMID: 23316452 DOI: 10.2174/2211555211201010012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This review describes recent research efforts focused on increasing the specificity of contrast agents for proton magnetic resonance imaging (MRI). Contrast agents play an indispensable role in MRI by enhancing the inherent contrast of images; however, the non-specific nature of current clinical contrast agents limits their usefulness. This limitation can be addressed by conjugating contrast agents or contrast-agent-loaded carriers-including polymers, nanoparticles, dendrimers, and liposomes-to molecules that bind to biological sites of interest. An alternative approach to conjugation is synthetically mimicking biological structures with metal complexes that are also contrast agents. In this review, we describe the advantages and limitations of these two targeting strategies with respect to translation from in vitro to in vivo imaging while focusing on advances from the last ten years.
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Wu X, Burden-Gulley SM, Yu GP, Tan M, Lindner D, Brady-Kalnay SM, Lu ZR. Synthesis and evaluation of a peptide targeted small molecular Gd-DOTA monoamide conjugate for MR molecular imaging of prostate cancer. Bioconjug Chem 2012; 23:1548-56. [PMID: 22812444 DOI: 10.1021/bc300009t] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Tumor extracellular matrix has an abundance of cancer related proteins that can be used as biomarkers for cancer molecular imaging. Innovative design and development of safe and effective targeted contrast agents to these biomarkers would allow effective MR cancer molecular imaging with high spatial resolution. In this study, we synthesized a low molecular weight CLT1 peptide targeted Gd(III) chelate CLT1-dL-(Gd-DOTA)(4) specific to clotted plasma proteins in tumor stroma for cancer MR molecular imaging. CLT1-dL-(Gd-DOTA)(4) was synthesized by conjugating four Gd-DOTA monoamide chelates to a CLT1 peptide via generation 1 lysine dendrimer. The T(1) relaxivity of CLT1-dL-(Gd-DOTA)(4) was 40.4 mM(-1) s(-1) per molecule (10.1 mM(-1) s(-1) per Gd) at 37 °C and 1.5 T. Fluorescence imaging showed high binding specificity of CLT1 to orthotopic PC3 prostate tumor in mice. The contrast agent resulted in improved tumor contrast enhancement in male athymic nude mice bearing orthotopic PC3 prostate tumor xenograft at a dose of 0.03 mmol Gd/kg. The peptide targeted MRI contrast agent is promising for high-resolution MR molecular imaging of prostate tumor.
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Affiliation(s)
- Xueming Wu
- Department of Biomedical Engineering, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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21
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Clofent-Sanchez G, Jacobin-Valat MJ, Laroche-Traineau J. The growing interest of fibrin imaging in atherosclerosis. Atherosclerosis 2012; 222:22-5. [DOI: 10.1016/j.atherosclerosis.2012.01.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 01/23/2012] [Indexed: 12/19/2022]
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von Elverfeldt D, Meißner M, Peter K, Paul D, Meixner F, Neudorfer I, Merkle A, Harloff A, Zirlik A, Schöllhorn J, Markl M, Hennig J, Bode C, von zur Muhlen C. An approach towards molecular imaging of activated platelets allows imaging of symptomatic human carotid plaques in a new model of a tissue flow chamber. CONTRAST MEDIA & MOLECULAR IMAGING 2012; 7:204-13. [DOI: 10.1002/cmmi.482] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
| | - Mirko Meißner
- Department of Radiology-Medical Physics; University Medical Center Freiburg; Germany
| | - Karlheinz Peter
- Atherothrombosis and Vascular Biology; Baker Heart Research Institute; Melbourne Australia
| | - Dominik Paul
- Department of Radiology-Medical Physics; University Medical Center Freiburg; Germany
| | - Fabian Meixner
- Department of Cardiology and Angiology; University Medical Center Freiburg; Germany
| | - Irene Neudorfer
- Department of Cardiology and Angiology; University Medical Center Freiburg; Germany
| | - Annette Merkle
- Department of Radiology-Medical Physics; University Medical Center Freiburg; Germany
| | - Andreas Harloff
- Department of Neurology and Neurophysiology; University Medical Center Freiburg; Germany
| | - Andreas Zirlik
- Department of Radiology-Medical Physics; University Medical Center Freiburg; Germany
| | - Joachim Schöllhorn
- Department of Cardiovascular Surgery; University Medical Center Freiburg; Germany
| | - Michael Markl
- Department of Radiology-Medical Physics; University Medical Center Freiburg; Germany
| | - Jürgen Hennig
- Department of Radiology-Medical Physics; University Medical Center Freiburg; Germany
| | - Christoph Bode
- Department of Cardiology and Angiology; University Medical Center Freiburg; Germany
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Kolodziej AF, Nair SA, Graham P, McMurry TJ, Ladner RC, Wescott C, Sexton DJ, Caravan P. Fibrin specific peptides derived by phage display: characterization of peptides and conjugates for imaging. Bioconjug Chem 2012; 23:548-56. [PMID: 22263840 DOI: 10.1021/bc200613e] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Peptides that bind to fibrin but not to fibrinogen or serum albumin were selected from phage display libraries as targeting moieties for thrombus molecular imaging probes. Three classes of cyclic peptides (cyclized via disulfide bond between two Cys) were identified with consensus sequences XArXCPY(G/D)LCArIX (Ar = aromatic, Tn6), X(2)CXYYGTCLX (Tn7), and NHGCYNSYGVPYCDYS (Tn10). These peptides bound to fibrin at ∼2 sites with K(d) = 4.1 μM, 4.0 μM, and 8.7 μM, respectively, whereas binding to fibrinogen was at least 100-fold weaker. The peptides also bind to the fibrin degradation product DD(E) with similar affinity to that measured for fibrin. The Tn7 and Tn10 peptides bind to the same site on fibrin, while the Tn6 peptides bind to a unique site. Alanine scanning identified the N- and C-terminal ends of the Tn6 and Tn7 peptides as most tolerant to modification. Peptide conjugates with either fluorescein or diethylenetriaminepentaaceto gadolinium(III) (GdDTPA) at the N-terminus were prepared for potential imaging applications, and these retained fibrin binding affinity and specificity in plasma. Relaxivity and binding studies on the GdDTPA derivatives revealed that an N-terminal glycyl linker had a modest effect on fibrin affinity but resulted in lower fibrin-bound relaxivity.
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Winter PM, Taylor MD. Magnetic Resonance Molecular Imaging of Plaque Angiogenesis. CURRENT CARDIOVASCULAR IMAGING REPORTS 2012. [DOI: 10.1007/s12410-011-9121-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Abstract
Molecular MRI plays an important role in studying molecular and cellular processes associated with heart disease. Targeted probes that recognize important biomarkers of atherosclerosis, apoptosis, necrosis, angiogenesis, thrombosis and inflammation have been developed. This review discusses the properties of chemically different contrast agents including iron oxide nanoparticles, gadolinium-based nanoparticles or micelles, discrete peptide conjugates and activatable probes. Numerous examples of contrast agents based on these approaches have been used in preclinical MRI of cardiovascular diseases. Clinical applications are still under investigation for some selected agents with highly promising initial results. Molecular MRI shows great potential for the detection and characterization of a wide range of cardiovascular diseases, as well as for monitoring response to therapy.
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Uppal R, Catana C, Ay I, Benner T, Sorensen AG, Caravan P. Bimodal thrombus imaging: simultaneous PET/MR imaging with a fibrin-targeted dual PET/MR probe--feasibility study in rat model. Radiology 2010; 258:812-20. [PMID: 21177389 DOI: 10.1148/radiol.10100881] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To image thrombus by using magnetic resonance (MR) imaging and positron emission tomography (PET) simultaneously in a rat arterial thrombus model with a dual PET/MR probe. MATERIALS AND METHODS Animal studies were approved by the institutional animal use committee. A dual PET/MR probe was synthesized by means of partial exchange of gadolinium for copper 64 ((64)Cu) in the fibrin-targeted MR probe EP-2104R. A preformed 25-mm thrombus was injected into the right internal carotid artery of a rat. Imaging was performed with a clinical 3.0-T MR imager with an MR-compatible human PET imager. Rats (n = 5) were imaged prior to and after systemic administration of the dual probe by using simultaneous PET/MR. The organ distribution of (64)Cu and gadolinium was determined ex vivo (n = 8), 2 hours after injection by using well counting and inductively coupled plasma mass spectrometry, respectively. Signal intensity ratios (SIRs) between the thrombus-containing and contralateral vessel were computed from PET images and MR data before and after probe administration. RESULTS The dual probe was synthesized with greater than 98% radiochemical purity. Thrombus enhancement was observed in all five animals at both MR (SIR([postprobe])/SIR([preprobe]) = 1.71 ± 0.35, P = .0053) and PET (SIR = 1.85 ± 0.48, P = .0087) after injection of the dual PET/MR probe. Ex vivo analysis at 2 hours after injection showed the highest (64)Cu and gadolinium concentrations, after the excretory organs (kidney and liver), to be in the thrombus. CONCLUSION A fibrin-targeted dual PET/MR probe enables simultaneous, direct MR and PET imaging of thrombus.
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Affiliation(s)
- Ritika Uppal
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, MA 02129, USA
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Winter PM, Caruthers SD, Lanza GM, Wickline SA. Quantitative cardiovascular magnetic resonance for molecular imaging. J Cardiovasc Magn Reson 2010; 12:62. [PMID: 21047411 PMCID: PMC2987770 DOI: 10.1186/1532-429x-12-62] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 11/03/2010] [Indexed: 12/14/2022] Open
Abstract
Cardiovascular magnetic resonance (CMR) molecular imaging aims to identify and map the expression of important biomarkers on a cellular scale utilizing contrast agents that are specifically targeted to the biochemical signatures of disease and are capable of generating sufficient image contrast. In some cases, the contrast agents may be designed to carry a drug payload or to be sensitive to important physiological factors, such as pH, temperature or oxygenation. In this review, examples will be presented that utilize a number of different molecular imaging quantification techniques, including measuring signal changes, calculating the area of contrast enhancement, mapping relaxation time changes or direct detection of contrast agents through multi-nuclear imaging or spectroscopy. The clinical application of CMR molecular imaging could offer far reaching benefits to patient populations, including early detection of therapeutic response, localizing ruptured atherosclerotic plaques, stratifying patients based on biochemical disease markers, tissue-specific drug delivery, confirmation and quantification of end-organ drug uptake, and noninvasive monitoring of disease recurrence. Eventually, such agents may play a leading role in reducing the human burden of cardiovascular disease, by providing early diagnosis, noninvasive monitoring and effective therapy with reduced side effects.
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Affiliation(s)
- Patrick M Winter
- Cincinnati Children's Hospital, Department of Radiology, 3333 Burnet Ave., ML 5033, Cincinnati, OH, 45229, USA
| | - Shelton D Caruthers
- Washington University, C-TRAIN Labs, 660 S. Euclid Ave., Campus Box 8215, St. Louis, MO, 63110, USA
| | - Gregory M Lanza
- Washington University, C-TRAIN Labs, 660 S. Euclid Ave., Campus Box 8215, St. Louis, MO, 63110, USA
| | - Samuel A Wickline
- Washington University, C-TRAIN Labs, 660 S. Euclid Ave., Campus Box 8215, St. Louis, MO, 63110, USA
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Hunsaker AR, Lu MT, Goldhaber SZ, Rybicki FJ. Imaging in acute pulmonary embolism with special clinical scenarios. Circ Cardiovasc Imaging 2010; 3:491-500. [PMID: 20647583 DOI: 10.1161/circimaging.109.855981] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Andetta R Hunsaker
- Applied Imaging Science Laboratory, the Thoracic Imaging Section, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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Molecular magnetic resonance imaging of deep vein thrombosis using a fibrin-targeted contrast agent: a feasibility study. Invest Radiol 2010; 44:146-50. [PMID: 19151606 DOI: 10.1097/rli.0b013e318195886d] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To evaluate the value of a fibrin-specific MR contrast agent (EP-2104R; EPIX Pharmaceuticals) for detection of deep vein thrombosis (DVT) and monitoring of percutaneous intervention for treatment. MATERIALS AND METHODS In 6 domestic swine, DVT was induced in an iliac/femoral vein using an occlusion-balloon catheter and subsequent injection of thrombin. The occluded vessels were recanalized by mechanical thrombectomy using a Fogarty catheter and an Arrow rotating thrombectomy device. Magnetic resonance imaging of the pelvis and lung was repeated 4 times (before and after DVT induction, after contrast agent administration, and after intervention) using a 1.5-T whole-body XMR system (ACS-NT, Philips Medical Systems, Best, NL). The visualization of the thrombi and contrast-to-noise ratio (CNR) was assessed. RESULTS EP-2104R allowed selective visualization of thrombi with accurate determination of the extent of DVT with high contrast (CNR: 65.3 +/- 17.2). After intervention, dislodged thrombus fragments were selectively visualized in the lung (CNR: 27.9 +/- 9.3). CONCLUSIONS Molecular magnetic resonance imaging using fibrin-specific MR contrast agent EP-2104R allowed for selective visualization of DVT and monitoring of percutaneous intervention.
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Uppal R, Ay I, Dai G, Kim YR, Sorensen AG, Caravan P. Molecular MRI of intracranial thrombus in a rat ischemic stroke model. Stroke 2010; 41:1271-7. [PMID: 20395615 DOI: 10.1161/strokeaha.109.575662] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Intracranial thrombus is a principal feature in most ischemic stroke, and thrombus location and size may correlate with outcome and response to thrombolytic therapy. EP-2104R is a fibrin-specific molecular MR agent that has previously been shown to enhance extracranial and venous sinus thrombi in animal models and, recently, in clinical trials. In this study, we examined whether this fibrin-specific MR probe could noninvasively characterize intracranial arterial thrombi. METHODS Embolic stroke was induced in adult rats by occlusion of the right internal carotid artery with an aged thrombus. We used diffusion-weighted imaging, time of flight angiography, and high-resolution 3-dimensional T1-weighted MRI at 4.7 T before and after use of contrast agents EP-2104R (n=6) and gadopentetate dimeglumine (n=5). RESULTS In all animals, MR angiography revealed a flow deficit and diffusion-weighted imaging showed hyperintensity consistent with ischemia. Using EP-2104R-enhanced MRI, we saw occlusive thrombi and vessel wall enhancement in all 6 animals with high contrast to noise relative to blood, whereas gadopentetate dimeglumine-injected animals showed no occlusive thrombus or vessel wall enhancement. The concentration of gadolinium in the thrombus after EP-2104R was 18 times that in the blood pool. CONCLUSIONS EP-2104R-enhanced MRI successfully identifies intracranial thrombus in a rat embolic stroke model.
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Affiliation(s)
- Ritika Uppal
- Department of Radiology, Massachusetts General Hospital-East, 149 13th Street, Suite 2301, Charlestown, MA 02129, USA
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Abstract
This review focuses on recent approaches in using targeted MRI probes for noninvasive molecular imaging of thrombosis. Probe design strategies are discussed: choice of molecular target; nanoparticle versus small-molecule probe; and gadolinium versus iron oxide imaging reporter. Examples of these different design strategies are chosen from the recent literature. Novel contrast agents used to image direct and indirect binding to fibrin have been described as well as direct binding to activated platelets. Emphasis is placed on probes where utility has been demonstrated in animal models or in human clinical trials.
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Affiliation(s)
- Katie L Ciesienski
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology, Harvard Medical School, 149 Thirteenth Street, Charlestown, MA 02129, USA
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Abstract
This article discusses the role of magnetic resonance angiography (MRA) in evaluating the pulmonary arterial system. For depiction of pulmonary arterial anatomy and morphology, MRA techniques are compared with CT angiography and digital subtraction x-ray angiography. Perfusion, flow, and function are emphasized, as the integrated MR examination offers a comprehensive assessment of vascular morphology and function. Advances in MR technology that improve spatial and temporal resolution and compensate for potential artifacts are reviewed as they pertain to pulmonary MRA. Current and emerging gadolinium contrast-enhanced and non-contrast-enhanced MRA techniques are discussed. The role of pulmonary MRA, clinical protocols, imaging findings, and interpretation pitfalls are reviewed for clinical indications.
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Affiliation(s)
- Elizabeth M Hecht
- Department of Radiology, New York University School of Medicine, 560 First Avenue, TCH-HW202, New York, NY 10016, USA.
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Sosnovik DE, Caravan P. Molecular MRI of Atherosclerotic Plaque With Targeted Contrast Agents. CURRENT CARDIOVASCULAR IMAGING REPORTS 2009; 2:87-94. [PMID: 20019886 DOI: 10.1007/s12410-009-0012-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Molecular MRI of atherosclerosis involves the use of novel contrast agents to image cellular and molecular processes within atherosclerotic plaque. Agents to image plaque lipid content, inflammation, angiogenesis, and thrombosis have been developed and studied extensively in animal models of atherosclerosis and vascular injury. Selected agents have also been studied in humans, with highly promising initial results. In this brief review, recent advances as well as opportunities and challenges in the field are discussed.
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MRI of vulnerable plaque. CURRENT CARDIOVASCULAR IMAGING REPORTS 2009. [DOI: 10.1007/s12410-009-0002-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Molecular imaging is a rapidly growing field with the potential to revolutionize cardiovascular medicine by shifting diagnostic focus from functional abnormalities which occur late in a disease process to the biochemical events which precipitate the earliest stages of disease. MRI is a modality well suited to this task as it allows a variety of contrast mechanisms for detection of epitopes of interest, as well as high-resolution anatomical localization and functional information. In this review, we discuss the widerange of available molecular MRI contrast agents and their application to diseases such as atherosclerosis, thrombus imaging, and stem cell tracking, along with opportunities for molecularly targeted drug delivery.
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Nolte IS, Gungor S, Erber R, Plaxina E, Scharf J, Misselwitz B, Gerigk L, Przybilla H, Groden C, Brockmann MA. In vitro labeling of glioma cells with gadofluorine M enhances T1 visibility without affecting glioma cell growth or motility. Magn Reson Med 2008; 59:1014-20. [PMID: 18429039 DOI: 10.1002/mrm.21503] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Gadofluorine is a novel macrocyclic, amphiphilic gadolinium-based contrast agent. We found that malignant glioma cells could be labeled in vitro using Gadofluorine without the need for transfection agents or any other additional means. Labeling with Gadofluorine enhanced the visualization of glioma cells in T(1)-weighted sequences, even if the cells had been cultured in medium without Gadofluorine over several days. The intracellular uptake of Gadofluorine was measured and the loss of relevant amounts of Gadofluorine into the cell culture medium was ruled out by MRI. Confocal laser fluorescence microscopy revealed Cy-5-labeled Gadofluorine in the perinuclear cytoplasmic region, but neither within the nucleus nor bound to the cell membrane. Adverse effects of cellular Gadofluorine uptake were ruled out by proliferation and migration assays. Finally, in vivo analyses provided good visibility of labeled glioma cells in T(1)-weighted sequences after intracerebral injection in mice for more than 2 weeks. We thus conclude that Gadofluorine can easily be used to label glioma cells in vitro without affecting glioma cell biology. Gadofluorine provides an interesting alternative for cellular labeling if iron oxide particles are incorporated insufficiently by target cells or if the vicinity of susceptibility artifacts prohibits the use of signal-decreasing contrast agents.
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Affiliation(s)
- Ingo S Nolte
- Department of Neuroradiology, University of Heidelberg, Medical Faculty Mannheim,Theodor-Kutzer-Ufer 1-3, Mannheim, Germany
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Overoye-Chan K, Koerner S, Looby RJ, Kolodziej AF, Zech SG, Deng Q, Chasse JM, McMurry TJ, Caravan P. EP-2104R: A Fibrin-Specific Gadolinium-Based MRI Contrast Agent for Detection of Thrombus. J Am Chem Soc 2008; 130:6025-39. [DOI: 10.1021/ja800834y] [Citation(s) in RCA: 180] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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MR imaging of thrombi using EP-2104R, a fibrin-specific contrast agent: initial results in patients. Eur Radiol 2008; 18:1995-2005. [PMID: 18425519 DOI: 10.1007/s00330-008-0965-2] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2007] [Revised: 02/23/2008] [Accepted: 03/05/2008] [Indexed: 12/19/2022]
Abstract
This study was an initial phase II trial in humans of molecular magnetic resonance (MR) imaging for improved visualization of thrombi in vessel territories potentially responsible for stroke using a new fibrin-specific contrast agent (EP-2104R). Eleven patients with thrombus in the left ventricle (n = 2), left or right atrium (n = 4), thoracic aorta (n = 4) or carotid artery (n = 1) as verified by an index examination (ultrasound, computed tomograpy, or conventional MR) were enrolled. All MR imaging was performed on 1.5 T whole-body MR-system using an inversion-recovery black-blood gradient-echo sequence. The same sequence was performed before and 2-6 h after low-dose intravenous administration of 4 mumol/kg EP-2104R. Two investigators assessed image quality and signal amplification. Furthermore, contrast-to-noise ratios (CNR) between the clot and the blood pool/surrounding soft tissue before and after administration of the contrast agent were compared using Student's t-test. MR imaging and data analysis were successfully completed in 10 patients. No major adverse effects occurred. On enhanced images, thrombi demonstrated high signal amplification, typically at the clot surface, with a significantly increased contrast in comparison to the surrounding blood pool and soft tissue (CNR for clot vs. blood pool, unenhanced and enhanced: 6 +/- 8 and 29 +/- 14; CNR for clot vs. soft tissue, unenhanced and enhanced: 0 +/- 4 and 21 +/- 13; P < 0.01 for both comparisons). EP-2104R allows for molecular MR imaging of thrombi potentially responsible for stroke. High contrast between thrombus and surrounding blood and soft tissues can be achieved with enhanced imaging.
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Spuentrup E, Katoh M, Buecker A, Fausten B, Wiethoff AJ, Wildberger JE, Haage P, Parsons EC, Botnar RM, Graham PB, Vettelschoss M, Günther RW. Molecular MR imaging of human thrombi in a swine model of pulmonary embolism using a fibrin-specific contrast agent. Invest Radiol 2007; 42:586-95. [PMID: 17620942 DOI: 10.1097/rli.0b013e31804fa154] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Molecular targeted MR imaging of human clots material in a model of pulmonary embolism using a fibrin-specific magnetic resonance imaging contrast agent (EP-2104R, EPIX Pharmaceuticals, Cambridge, MA). MATERIAL AND METHODS Fresh ex vivo engineered thrombi (human blood) and human clots removed from patients were delivered in 11 swine. Molecular MR imaging with a 3D gradient-echo [3D fast field echo (3DFFE)] sequence and a navigator-gated and cardiac-triggered 3D inversion-recovery black-blood gradient-echo sequence (IR) was performed before thrombus delivery, after thrombus delivery but before contrast media application, and 2 hours after i.v. administration of 4 micromol/kg EP-2104R. MR images were analyzed by 2 investigators and contrast-to-noise ratio (CNR) was assessed. Thrombi were removed for assessment of gadolinium (Gd) concentration. RESULTS Only after contrast media application were pulmonary emboli [freshly engineered thrombi (n = 23) and human clot material removed from patients (n = 25)] visualized as white foci on MR images. CNR was 13 +/- 3 (ex vivo engineered clot) and 22 +/- 9 (patient clot material) for the fast field echo (FFE)-sequence and 29 +/- 9 (ex vivo engineered clot) and 43 +/- 18 (patient clot material) for the IR-sequence, respectively. A high Gd concentration in the clots was found (82 +/- 43 microM for the freshly engineered and 247 +/- 44 microM for the clots removed from patients, respectively). CONCLUSIONS EP-2104R allows for molecular MR imaging of human clot material in the pulmonary vessels of a swine model.
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Affiliation(s)
- Elmar Spuentrup
- Departments of Diagnostic Radiology, Aachen Technical University, Aachen, Germany.
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Affiliation(s)
- Farouc A Jaffer
- Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
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Wickline SA, Neubauer AM, Winter PM, Caruthers SD, Lanza GM. Molecular imaging and therapy of atherosclerosis with targeted nanoparticles. J Magn Reson Imaging 2007; 25:667-80. [PMID: 17347992 DOI: 10.1002/jmri.20866] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Advances in bionanotechnology are poised to impact the field of cardiovascular diagnosis and therapy for decades to come. This review seeks to illustrate selected examples of newly developed diagnostic and therapeutic nanosystems that have been evaluated in experimental atherosclerosis, thrombosis, and vascular biology. We review a variety of nanotechnologies that are capable of detecting early cardiovascular pathology, as well as associated imaging approaches and conjunctive strategies for site-targeted treatment with nanoparticle delivery systems.
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Affiliation(s)
- Samuel A Wickline
- Department of Medicine, Washington University, St. Louis, Missouri 63110, USA.
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Stracke CP, Katoh M, Wiethoff AJ, Parsons EC, Spangenberg P, Spüntrup E. Molecular MRI of cerebral venous sinus thrombosis using a new fibrin-specific MR contrast agent. Stroke 2007; 38:1476-81. [PMID: 17379818 DOI: 10.1161/strokeaha.106.479998] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Imaging of cerebral vein thrombosis is still challenging. Currently, diagnosis is based on CT venography and MRI including MRA and conventional digital subtraction angiography. However, especially in chronic cases, each method has shown its limitations. Newer strategies for MRI are found on molecular imaging using targeted contrast agents. The aim of this study was to prove the feasibility of a novel fibrin-targeted MR contrast agent (EP-2104R; EPIX Pharmaceuticals) for selective imaging of sinus venous thrombosis in an animal model. METHODS Thrombosis of the superior sagittal sinus with human blood was induced in 6 pigs using a combined microsurgical and interventional approach. MRI was then performed before and up to 120 minutes after injection of 4 micromol/kg body weight EP-2104R. Molecular imaging was performed with a 3-dimensional high-resolution T1-weighted gradient echo sequence. Time courses of signal-to-noise ratio and contrast-to-noise ratio were analyzed. Thrombi were then surgically removed and the Gadolinium concentration was assessed. RESULTS In all cases the thrombosis could be successfully induced; the complete MR protocol could be performed in 5 animals. In these cases the thrombi showed selective enhancement after injection of the molecular contrast agent. However, a continuous contrast-to-noise ratio increase was seen up to 120 minutes after contrast administration, achieving a contrast-to-noise ratio of 14.2+/-0.7 between clot and the blood pool. CONCLUSIONS The novel fibrin-targeted molecular MR contrast EP-2104R allows selective and high-contrast imaging of cerebral sinus vein thrombosis in an animal model.
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Briley-Saebo KC, Mulder WJM, Mani V, Hyafil F, Amirbekian V, Aguinaldo JGS, Fisher EA, Fayad ZA. Magnetic resonance imaging of vulnerable atherosclerotic plaques: Current imaging strategies and molecular imaging probes. J Magn Reson Imaging 2007; 26:460-79. [PMID: 17729343 DOI: 10.1002/jmri.20989] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The vulnerability or destabilization of atherosclerotic plaques has been directly linked to plaque composition. Imaging modalities, such as magnetic resonance (MR) imaging, that allow for evaluation of plaque composition at a cellular and molecular level, could further improve the detection of vulnerable plaque and may allow for monitoring the efficacy of antiatherosclerotic therapies. In this review we focus on MR imaging strategies for the detection and evaluation of atherosclerotic plaques and their composition. We highlight recent advancements in the development of MR pulse sequences, computer image analysis, and the use of commercially available MR contrast agents, such as gadopentic acid (Gd-DTPA), for plaque characterization. We also discuss molecular imaging strategies that are currently being used to design specific imaging probes targeted to biochemical and cellular markers of atherosclerotic plaque vulnerability.
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Affiliation(s)
- Karen C Briley-Saebo
- Imaging Science Laboratories, Department of Radiology, Mount Sinai School of Medicine, New York, New York, USA
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Affiliation(s)
- Marius M Hoeper
- Department of Respiratory Medicine, Hannover Medical School, 30623 Hannover, Germany.
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Spuentrup E, Botnar RM. Coronary magnetic resonance imaging: visualization of the vessel lumen and the vessel wall and molecular imaging of arteriothrombosis. Eur Radiol 2005; 16:1-14. [PMID: 16132919 DOI: 10.1007/s00330-005-2886-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Revised: 06/22/2005] [Accepted: 07/08/2005] [Indexed: 01/21/2023]
Abstract
Coronary magnetic resonance (MR) imaging has dramatically emerged over the last decade. Technical improvements have enabled reliable visualization of the proximal and midportion of the coronary artery tree for exclusion of significant coronary artery disease. However, current technical developments focus also on direct visualization of the diseased coronary vessel wall and imaging of coronary plaque because plaques without stenoses are typically more vulnerable with higher risk of plaque rupture. Plaque rupture with subsequent thrombosis and vessel occlusion is the main cause of myocardial infarction. Very recently, the first success of molecular imaging in the coronary arteries has been demonstrated using a fibrin-specific contrast agent for selective visualization of coronary thrombosis. This demonstrates in general the high potential of molecular MR imaging in the field of coronary artery disease. In this review, we will address recent technical advances in coronary MR imaging, including visualization of the lumen and the vessel wall and molecular imaging of coronary arteriothrombosis. First results of these new approaches will be discussed.
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Affiliation(s)
- Elmar Spuentrup
- Department of Diagnostic Radiology, University Hospital, Aachen Technical University, Pauwelsstrasse 30, 52057, Aachen, Germany.
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