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Sampson UKA, Harrell FE, Fazio S, Nwosu S, Mercaldo N, Mensah GA, Davidson MH, Coll B, Feinstein SB. Carotid Adventitial Vasa Vasorum and Intima-Media Thickness in a Primary Prevention Population. Echocardiography 2014; 32:264-70. [DOI: 10.1111/echo.12646] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Uchechukwu K. A. Sampson
- Department of Medicine; Vanderbilt University Medical Center (VUMC); Nashville Tennessee
- Department of Pathology; Microbiology and Immunology; VUMC; Nashville Tennessee
- Department of Radiology and Radiological Sciences; VUMC; Nashville Tennessee
| | | | - Sergio Fazio
- Department of Medicine; Vanderbilt University Medical Center (VUMC); Nashville Tennessee
- Department of Pathology; Microbiology and Immunology; VUMC; Nashville Tennessee
| | - Sam Nwosu
- Department of Biostatistics; VUMC; Nashville Tennessee
| | - Nate Mercaldo
- Department of Biostatistics; VUMC; Nashville Tennessee
| | - George A. Mensah
- Department of Medicine; University of Cape Town; Cape Town South Africa
| | | | - Blai Coll
- Abbott Laboratories; Abbott Park Illinois
| | - Steve B. Feinstein
- Department of Internal Medicine; Section of Cardiology; Rush University Medical Center; Chicago Illinois
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52
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Yu FTH, Villanueva FS, Chen X. Radial modulation contrast imaging using a 20-MHz single-element intravascular ultrasound catheter. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2014; 61:779-791. [PMID: 24803134 DOI: 10.1109/tuffc.2014.2970] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Contrast-enhanced intravascular ultrasound imaging is a promising tool for the characterization of coronary vasa vasorum proliferation, which has been identified as a marker of, and possible etiologic factor in, the development of high-risk atherosclerotic plaques. Resonance-based nonlinear detection methods have required the development of prototype catheters which are not commercially available, thus limiting clinical translation. In this study, we investigated the performances of a radial modulation imaging approach (25/3 MHz combination) using simulations, implemented it on a clinical 20-MHz rotating catheter, and tested it in a wall-less tissue-mimicking flow phantom perfused with lipid-encapsulated microbubbles (MBs). The effects of the phase lag, low-frequency pressure, and MB concentration on the envelope subtracted radial modulation signals were investigated as a function of depth. Our dual-pulse dual-frequency approach produced contrast- specific images with contrast-to-tissue improvements over B-mode of 15.1 ± 2.1 dB at 2 mm and 6.8 ± 0.1 dB at 4 mm depths. Using this imaging strategy, 200-μm-diameter cellulose tubing perfused with MBs could be resolved while surrounding tissue scattering was suppressed. These results raise promise for the detection of coronary vasa vasorum and may ultimately facilitate the detection of plaque at risk for rupture.
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Atherosclerosis and atheroma plaque rupture: imaging modalities in the visualization of vasa vasorum and atherosclerotic plaques. ScientificWorldJournal 2014; 2014:312764. [PMID: 24688380 PMCID: PMC3944209 DOI: 10.1155/2014/312764] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 12/30/2013] [Indexed: 11/24/2022] Open
Abstract
Invasive angiography has been widely accepted as the gold standard to diagnose cardiovascular pathologies. Despite its superior resolution of demonstrating atherosclerotic plaque in terms of degree of lumen stenosis, the morphological assessment for the plaque is insufficient for the analysis of plaque components, and therefore, unable to predict the risk status or vulnerability of atherosclerotic plaque. There is an increased body of evidence to show that the vasa vasorum play an important role in the initiation, progression, and complications of atherosclerotic plaque leading to major adverse cardiac events. This paper provides an overview of the evidence-based reviews of various imaging modalities with regard to their potential value for comprehensive characterization of the composition, burden, and neovascularization of atherosclerotic plaque.
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Abstract
With the implementation of gene therapy looming in the near term, an effective delivery system using noninvasive, nonviral-mediated methods appears as an attractive option. This novel platform technology uses gas-filled, ultrasound-directed acoustic microspheres for both diagnostic imaging and therapy and yet may provide a key component for future success in the pursuit of single-gene replacement therapy.
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Affiliation(s)
- Jason Castle
- GE Global Research Niskayuna, Schenectady, NY, USA
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55
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Parker JM, Weller MW, Feinstein LM, Adams RJ, Main ML, Grayburn PA, Cosgrove DO, Goldberg BA, Darge K, Nihoyannopoulos P, Wilson S, Monaghan M, Piscaglia F, Fowlkes B, Mathias W, Moriyasu F, Chammas MC, Greenbaum L, Feinstein SB. Safety of ultrasound contrast agents in patients with known or suspected cardiac shunts. Am J Cardiol 2013; 112:1039-45. [PMID: 23816393 DOI: 10.1016/j.amjcard.2013.05.042] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 05/08/2013] [Accepted: 05/08/2013] [Indexed: 12/01/2022]
Abstract
Contrast-enhanced ultrasound imaging is a radiation-free diagnostic tool that uses biocompatible ultrasound contrast agents (UCAs) to improve image clarity. UCAs, which do not contain dye, often salvage "technically difficult" ultrasound scans, increasing the accuracy and reliability of a front-line ultrasound diagnosis, reducing unnecessary downstream testing, lowering overall health care costs, changing therapy, and improving patient care. Two UCAs currently are approved and regulated by the US Food and Drug Administration. They have favorable safety profiles and risk/benefit ratios in adult and pediatric populations, including compromised patients with severe cardiovascular diseases. Nevertheless, these UCAs are contraindicated in patients with known or suspected right-to-left, bidirectional, or transient right-to-left cardiac shunts. These patients, who constitute 10% to 35% of the general population, typically receive no UCAs when they undergo echocardiography. If their echocardiographic images are suboptimal, they may receive inappropriate diagnosis and treatment, or they may be referred for additional diagnostic testing, including radiation-based procedures that increase their lifetime risk for cancer or procedures that use contrast agents containing dye, which may increase the risk for kidney damage. An exhaustive review of current peer-reviewed research demonstrated no scientific basis for the UCA contraindication in patients with known or suspected cardiac shunts. Initial safety concerns were based on limited rodent data and speculation related to macroaggregated albumin microspheres, a radioactive nuclear imaging agent with different physical and chemical properties and no relation to UCAs. Radioactive macroaggregated albumin is not contraindicated in adult or pediatric patients with cardiac shunts and is routinely used in these populations. In conclusion, the International Contrast Ultrasound Society Board recommends removal of the contraindication to further the public interest in safe, reliable, radiation-free diagnostic imaging options for patients with known or suspected cardiac shunts and to reduce their need for unnecessary downstream testing.
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Abstract
Grayscale transrectal ultrasonographic prostate biopsy using local anesthesia remains the standard approach to the definitive diagnosis of prostate cancer. Careful patient evaluation and preparation are essential to maximize the results and minimize the complications of the biopsy procedure.
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Affiliation(s)
- Mohamed T Ismail
- Department of Urology, VA Medical Center, 1601 Kirkwood Highway, Wilmington, DE 19805, USA; Department of Urology, Thomas Jefferson University, 1025 Walnut Street, 1102, Philadelphia, PA 19107, USA
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57
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Kuenen MPJ, Saidov TA, Wijkstra H, Mischi M. Contrast-ultrasound dispersion imaging for prostate cancer localization by improved spatiotemporal similarity analysis. ULTRASOUND IN MEDICINE & BIOLOGY 2013; 39:1631-41. [PMID: 23791350 DOI: 10.1016/j.ultrasmedbio.2013.03.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 01/18/2013] [Accepted: 03/05/2013] [Indexed: 05/14/2023]
Abstract
Angiogenesis plays a major role in prostate cancer growth. Despite extensive research on blood perfusion imaging aimed at angiogenesis detection, the diagnosis of prostate cancer still requires systematic biopsies. This may be due to the complex relationship between angiogenesis and microvascular perfusion. Analysis of ultrasound-contrast-agent dispersion kinetics, determined by multipath trajectories in the microcirculation, may provide better characterization of the microvascular architecture. We propose the physical rationale for dispersion estimation by an existing spatiotemporal similarity analysis. After an intravenous ultrasound-contrast-agent bolus injection, dispersion is estimated by coherence analysis among time-intensity curves measured at neighbor pixels. The accuracy of the method is increased by time-domain windowing and anisotropic spatial filtering for speckle regularization. The results in 12 patient data sets indicated superior agreement with histology (receiver operating characteristic curve area = 0.88) compared with those obtained by reported perfusion and dispersion analyses, providing a valuable contribution to prostate cancer localization.
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Affiliation(s)
- M P J Kuenen
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
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58
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Zhu Y, Deng YB, Liu YN, Bi XJ, Sun J, Tang QY, Deng Q. Use of Carotid Plaque Neovascularization at Contrast-enhanced US to Predict Coronary Events in Patients with Coronary Artery Disease. Radiology 2013; 268:54-60. [DOI: 10.1148/radiol.13122112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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59
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Correlation between enhanced intensity of atherosclerotic plaque at contrast-enhanced ultrasonography and density of histological neovascularization. ACTA ACUST UNITED AC 2013; 33:443-446. [DOI: 10.1007/s11596-013-1139-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Indexed: 11/26/2022]
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60
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Ohrndorf S, Backhaus M. Musculoskeletal ultrasonography in patients with rheumatoid arthritis. Nat Rev Rheumatol 2013; 9:433-7. [DOI: 10.1038/nrrheum.2013.73] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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61
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Villa R, Cerroni B, Viganò L, Margheritelli S, Abolafio G, Oddo L, Paradossi G, Zaffaroni N. Targeted doxorubicin delivery by chitosan-galactosylated modified polymer microbubbles to hepatocarcinoma cells. Colloids Surf B Biointerfaces 2013; 110:434-42. [PMID: 23759384 DOI: 10.1016/j.colsurfb.2013.04.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 04/18/2013] [Accepted: 04/22/2013] [Indexed: 10/26/2022]
Abstract
Targeted drug delivery is a main issue in cancer treatment. Taking advantage of recently developed polyvinyl alcohol (PVA)-based microbubbles, which are characterized by chemical versatility of the polymeric surface thereby allowing coating with different ligands, we set up a strategy for the targeted delivery of the anticancer agent doxorubicin to hepatocarcinoma cells. Such microbubbles are exceptionally efficient ultrasound scatterers and thus represent also an option as potential ultrasound contrast agents. Moreover, the oscillation of microbubbles induced by ultrasound could contribute to favor the release of drugs allocated on shell. Specifically, PVA-based microbubbles were reacted with a galactosylated chitosan complex and loaded with doxorubicin to enable the localization and drug delivery to HepG2 hepatocarcinoma cells overexpressing asialoglycoprotein receptors. We demonstrated selectivity and greater bioadhesive properties of the functionalized microbubbles for tumor cells than to normal fibroblasts, which were influenced by the degree of galactosylation. The presence of galactosylated chitosan did not modify the rate of doxorubicin release from microbubbles, whichwas almost complete within 48h. Cellular uptake of doxorubicin loaded on functionalized microbubbles was higher in HepG2 than in normal fibroblasts, which do not over express the asialoglycoprotein receptors. In addition, doxorubicin loaded onto functionalized microbubbles fully retained its cytotoxic activity. Cells were also irradiated with ultrasound, immediately after exposure to microbubbles. An early enhancement of doxorubicin release and cellular drug uptake associated to a concomitant increase in cytotoxicity was observed in HepG2 cells. Overall, results of the study indicate that galactosylated chitosan microbubbles represent promising devices for the targeted delivery of antitumor agents to liver cancer cells.
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Affiliation(s)
- Raffaella Villa
- Dipartimento di Oncologia Sperimentale e Medicina Molecolare, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Amadeo 42, 20133 Milano, Italy.
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62
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Krasia-Christoforou T, Georgiou TK. Polymeric theranostics: using polymer-based systems for simultaneous imaging and therapy. J Mater Chem B 2013; 1:3002-3025. [PMID: 32261003 DOI: 10.1039/c3tb20191k] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Polymer-based nanomedicine is a large and fast growing field. Polymer-based systems have been extensively used as therapeutic carriers as well as bioimaging agents for example in tumour diagnosis. However, fewer polymeric systems have been able to combine both therapy and imaging in a new field that is called theranostics (theragnostics). This review aims to summarise the recent developments and trends on polymeric theranostics. Four different types of therapies/treatments are examined namely drug delivery, gene delivery, photodynamic therapy and hyperthermia treatment combined with different imaging moieties like magnetic resonance imaging agents, fluorescent agents and microbubbles for ultrasound imaging.
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Affiliation(s)
- Theodora Krasia-Christoforou
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus.
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63
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Li Y, Tang J, Fei X, Gao Y. Diagnostic performance of contrast enhanced ultrasound in patients with prostate cancer: a meta-analysis. Acad Radiol 2013; 20:156-64. [PMID: 23103186 DOI: 10.1016/j.acra.2012.09.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 09/14/2012] [Accepted: 09/14/2012] [Indexed: 01/05/2023]
Abstract
RATIONALE AND OBJECTIVES We aimed to do a meta-analysis of the existing literature to assess the accuracy of prostate cancer (PCa) studies that use contrast-enhanced ultrasound (CEUS) as a diagnostic tool. MATERIALS AND METHODS The MEDLINE, EMBASE, and Cochrane Library databases were searched for relevant original articles published up to August 2012. Characteristics of Included studies were recorded. Methodological quality was assessed by using the quality assessment of diagnostic studies tool. Pooled weighted estimates of diagnostic odds ratio (DOR), sensitivity, specificity, and positive and negative likelihood ratio (LR) were calculated. A summary receiver operator characteristic (SROC) curve was constructed to calculate the area under the curve (AUC). Publication bias analysis was also performed. RESULTS Sixteen studies (2624 patients) were included in the meta-analysis. Various contrast agents and imaging modes were applied. The independent random-effects summary showed a variation in diagnostic values. The summary estimates of sensitivity, specificity, and DOR were 0.70, 0.74, and 9.09, respectively. The weighted positive and negative LR were 2.81 and 0.35, with statistically significant between-study heterogeneity (P < .001). Sensitivity was better in positive patient studies than positive biopsy cores ones (0.78 vs. 0.64). SROC plot displayed value for AUC (0.82). Begg's test (P = .822) and Egger's test (P = .198) did not show evidence of publication bias. CONCLUSION CEUS is a promising tool in the detection of PCa, but it cannot completely replace systematic biopsy under the present circumstances. It is necessary to standardize imaging techniques, contrast agents and diagnostic criteria. Large samples, multi-center studies and high-quality prospective trials are necessary to assess its clinical value.
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Affiliation(s)
- Yanmi Li
- Department of Ultrasound, Chinese People's Liberation Army General Hospital, 28 Fuxing Road, Beijing, 100853, P. R. China.
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64
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Castle J, Butts M, Healey A, Kent K, Marino M, Feinstein SB. Ultrasound-mediated targeted drug delivery: recent success and remaining challenges. Am J Physiol Heart Circ Physiol 2012. [PMID: 23203969 DOI: 10.1152/ajpheart.00265.2012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The potential clinical value of developing a novel, nonviral, ultrasound-directed gene and drug delivery system is immense. Investigators soon will initiate clinical trials with the goal of treating a wide variety of maladies using noninvasive, ultrasound-based technology. The ongoing, scientific validation associated with promising preclinical success portents a novel range of therapeutics. The clinical utility and eventual clinical successes await vigorous testing. This review highlights the recent successes and challenges within the field of ultrasound-mediated drug delivery.
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Affiliation(s)
- Jason Castle
- General Electric Global Research, Niskayuna, New York, USA
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65
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Alzaraa A, Gravante G, Chung WY, Al-Leswas D, Bruno M, Dennison AR, Lloyd DM. Targeted microbubbles in the experimental and clinical setting. Am J Surg 2012; 204:355-66. [PMID: 22920405 DOI: 10.1016/j.amjsurg.2011.10.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 10/12/2011] [Accepted: 10/12/2011] [Indexed: 01/17/2023]
Abstract
BACKGROUND Microbubbles have improved ultrasonography imaging techniques over the past 2 decades. Their safety, versatility, and easiness of use have rendered them equal or even superior in some instances to other imaging modalities such as computed tomography and magnetic resonance imaging. Herein, we conducted a literature review to present their types, general behavior in tissues, and current and potential use in clinical practice. METHODS A literature search was conducted for all preclinical and clinical studies involving microbubbles and ultrasonography. RESULTS Different types of microbubbles are available. These generally improve the enhancement of tissues during ultrasonography imaging. They also can be attached to ligands for the target of several conditions such as inflammation, angiogenesis, thrombosis, apoptosis, and might have the potential of carrying toxic drugs to diseased sites, thereby limiting the systemic adverse effects. CONCLUSIONS The use of microbubbles is evolving rapidly and can have a significant impact on the management of various conditions. The potential for their use as targeting agents and gene and drug delivery vehicles looks promising.
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Affiliation(s)
- Ahmed Alzaraa
- Department of Hepatobiliary and Pancreatic Surgery, NHS Trust, Leicester General Hospital, Gwendolen Rd., Leicester, LE5 4PW, UK.
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66
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Goertz DE, Frijlink ME, Krams R, de Jong N, van der Steen AFW. Vasa vasorum and molecular imaging of atherosclerotic plaques using nonlinear contrast intravascular ultrasound. Neth Heart J 2012; 15:77-80. [PMID: 18604278 DOI: 10.1007/bf03085959] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- D E Goertz
- Biomedical Engineering Department, Erasmus Medical Centre, Rotterdam, the Netherlands and Interuniversity Cardiology Institute of the Netherlands
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67
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Vicenzini E, Giannoni MF, Sirimarco G, Ricciardi MC, Toscano M, Lenzi GL, Di Piero V. Imaging of plaque perfusion using contrast-enhanced ultrasound – Clinical significance. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.permed.2012.03.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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68
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Soloperto G, Casciaro S. Progress in atherosclerotic plaque imaging. World J Radiol 2012; 4:353-71. [PMID: 22937215 PMCID: PMC3430733 DOI: 10.4329/wjr.v4.i8.353] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/14/2012] [Accepted: 05/21/2012] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular diseases are the primary cause of mortality in the industrialized world, and arterial obstruction, triggered by rupture-prone atherosclerotic plaques, lead to myocardial infarction and cerebral stroke. Vulnerable plaques do not necessarily occur with flow-limiting stenosis, thus conventional luminographic assessment of the pathology fails to identify unstable lesions. In this review we discuss the currently available imaging modalities used to investigate morphological features and biological characteristics of the atherosclerotic plaque. The different imaging modalities such as ultrasound, magnetic resonance imaging, computed tomography, nuclear imaging and their intravascular applications are illustrated, highlighting their specific diagnostic potential. Clinically available and upcoming methodologies are also reviewed along with the related challenges in their clinical translation, concerning the specific invasiveness, accuracy and cost-effectiveness of these methods.
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69
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Binzoni T, Tchernin D, Richiardi J, Van De Ville D, Hyacinthe JN. Haemodynamic responses to temperature changes of human skeletal muscle studied by laser-Doppler flowmetry. Physiol Meas 2012; 33:1181-97. [PMID: 22735191 DOI: 10.1088/0967-3334/33/7/1181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Using a small, but very instructive experiment, it is demonstrated that laser-Doppler flowmetry (LDF) at large interoptode spacing represents a unique tool for new investigations of thermoregulatory processes modulating the blood flow of small muscle masses in humans. It is shown on five healthy subjects that steady-state values of blood flow (perfusion) in the thenar eminence muscle group depend in a complex manner on both the local intramuscular temperature and local skin temperature, while the values of blood flow parameters measured during physiological transients, such as the post-ischaemic hyperhaemic response, depend only on the intramuscular temperature. In addition, it is shown that the so-called biological zero (i.e. remaining LDF signal during arterial occlusion) is influenced not only as expected by the intramuscular temperature, but also by the skin temperature. The proposed results reveal that the skeletal muscle has unique thermoregulatory characteristics compared, for example, to human skin. These and other observations represent new findings and we hope that they will serve as a stimulus for the creation of new experimental protocols leading to better understanding of blood flow regulation.
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Affiliation(s)
- Tiziano Binzoni
- Département de Neurosciences Fondamentales, University of Geneva, Geneva, Switzerland.
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70
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Mischi M, Kuenen MPJ, Wijkstra H. Angiogenesis imaging by spatiotemporal analysis of ultrasound contrast agent dispersion kinetics. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2012; 59:621-9. [PMID: 22547274 DOI: 10.1109/tuffc.2012.2241] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The key role of angiogenesis in cancer growth has motivated extensive research with the goal of noninvasive cancer detection by blood perfusion imaging. However, the results are still limited and the diagnosis of major forms of cancer, such as prostate cancer, are currently based on systematic biopsies. The difficulty in the detection of angiogenesis partly resides in a complex relationship between angiogenesis and perfusion. This may be overcome by analysis of the dispersion kinetics of ultrasound contrast agents. Determined by multipath trajectories through the microvasculature, dispersion permits a better characterization of the microvascular architecture and, therefore, more accurate detection of angiogenesis. In this paper, a novel dispersion analysis method is proposed for prostate cancer localization. An ultrasound contrast agent bolus is injected intravenously. Spatiotemporal analysis of the concentration evolution measured at different pixels in the prostate is used to assess the local dispersion kinetics of the injected agent. In particular, based on simulations of the convective diffusion equation, the similarity between the concentration evolutions at neighbor pixels is the adopted dispersion measure. Six measurements in patients, compared with the histology, provided a receiver operating characteristic curve integral equal to 0.87. This result was superior to that obtained by the previous approaches reported in the literature.
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Affiliation(s)
- Massimo Mischi
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
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71
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Szíjjártó C, Rossi S, Waton G, Krafft MP. Effects of perfluorocarbon gases on the size and stability characteristics of phospholipid-coated microbubbles: osmotic effect versus interfacial film stabilization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:1182-1189. [PMID: 22176688 DOI: 10.1021/la2043944] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Micrometer-sized bubbles coated with phospholipids are used as contrast agents for ultrasound imaging and have potential for oxygen, drug, and gene delivery and as therapeutic devices. An internal perfluorocarbon (FC) gas is generally used to stabilize them osmotically. We report here on the effects of three relatively heavy FCs, perfluorohexane (F-hexane), perfluorodiglyme (F-diglyme ), and perfluorotriglyme (F-triglyme), on the size and stability characteristics of microbubbles coated with a soft shell of dimyristoylphosphatidylcholine (DMPC) and on the surface tension and compressibility of DMPC monolayers. Monomodal populations of small bubbles (~1.3 ± 0.2 μm in radius, polydispersivity index ~8%) were prepared by sonication, followed by centrifugal fractionation. The mean microbubble size, size distribution, and stability were determined by acoustical attenuation measurements, static light scattering, and optical microscopy. The half-lives of F-hexane- and F-diglyme-stabilized bubbles (149 ± 8 and 134 ± 3 min, respectively) were about 2 times longer than with the heavier F-triglyme (76 ± 7 min) and 4-5 times longer than with air (34 ± 3 min). Remarkably, the bubbles are smaller than the minimal size values calculated assuming that the bubbles are stabilized osmotically by the insoluble FC gases. Particularly striking is that bubbles 2 orders of magnitude smaller than the calculated collapse radius can be prepared with F-triglyme, while its very low vapor pressure prohibits any osmotic effect. The interface between an aqueous DMPC dispersion and air, or air (or N(2)) saturated with the FCs, was investigated by tensiometry and by Langmuir monolayer compressions. Remarkably, after 3 h, the tensions at the interface between an aqueous DMPC dispersion (0.5 mmol L(-1)) and air were lowered from ~50 ± 1 to ~37 ± 1 mN m(-1) when F-hexane and F-diglyme were present and to ~40 ± 1 mN m(-1) for F-triglyme. Also noteworthy, the adsorption kinetics of DMPC at the interface, as obtained by dynamic tensiometry, were accelerated up to 3-fold when the FC gases were present. The compression isotherms show that all these FC gases significantly increase the surface pressure (from ~0 to ~10 mN m(-1)) at large molecular areas (70 Å(2)), implying their incorporation into the DMPC monolayer. All three FC gases increase the monolayer's collapse pressures significantly (~61 ± 2 mN m(-1)) as compared to air (~54 ± 2 mN m(-1)), providing for interfacial tensions as low as ~11 mN m(-1) (vs ~18 mN m(-1) in their absence). The FC gases increase the compressibility of the DMPC monolayer by 20-50%. These results establish that, besides their osmotic effect, FC gases contribute to bubble stabilization by decreasing the DMPC interfacial tension, hence reducing the Laplace pressure. This contribution, although significant, still does not suffice to explain the large discrepancy observed between calculated and experimental bubble half-lives. The case of F-triglyme, which has no osmotic effect, indicates that its effects on the DMPC shell (increased collapse pressure, decreased interfacial tension, and increased compressibility) contribute to bubble stabilization. F-hexane and F-diglyme provided both the smallest mean bubble sizes and the longest bubble half-lives.
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Affiliation(s)
- Csongor Szíjjártó
- Systèmes Organisés Fluorés à Finalités Thérapeutiques (SOFFT), Institut Charles Sadron (CNRS, UPR 22), Université de Strasbourg, 23 rue du Loess, 67034 Strasbourg Cedex 2, France
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Krafft MP. Controlling phospholipid self-assembly and film properties using highly fluorinated components – Fluorinated monolayers, vesicles, emulsions and microbubbles. Biochimie 2012; 94:11-25. [DOI: 10.1016/j.biochi.2011.07.027] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 07/19/2011] [Indexed: 01/23/2023]
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Marshall G, Sykes A, Berry J, Jonker L. The “humble” bubble: Contrast-enhanced ultrasound. Radiography (Lond) 2011. [DOI: 10.1016/j.radi.2011.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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74
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Sijl J, Vos HJ, Rozendal T, de Jong N, Lohse D, Versluis M. Combined optical and acoustical detection of single microbubble dynamics. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 130:3271-81. [PMID: 22087999 DOI: 10.1121/1.3626155] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A detailed understanding of the response of single microbubbles subjected to ultrasound is fundamental to a full understanding of the contrast-enhancing abilities of microbubbles in medical ultrasound imaging, in targeted molecular imaging with ultrasound, and in ultrasound-mediated drug delivery with microbubbles. Here, single microbubbles are isolated and their ultrasound-induced radial dynamics recorded with an ultra-high-speed camera at up to 25 million frames per second. The sound emission is recorded simultaneously with a calibrated single element transducer. It is shown that the sound emission can be predicted directly from the optically recorded radial dynamics, and vice versa, that the nanometer-scale radial dynamics can be predicted from the acoustic response recorded in the far field.
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Affiliation(s)
- Jeroen Sijl
- Physics of Fluids Group and MIRA Institute of Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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75
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de Korte CL, Hansen HHG, van der Steen AFW. Vascular ultrasound for atherosclerosis imaging. Interface Focus 2011; 1:565-75. [PMID: 22866231 PMCID: PMC3262270 DOI: 10.1098/rsfs.2011.0024] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 05/11/2011] [Indexed: 11/12/2022] Open
Abstract
Cardiovascular disease is a leading cause of death in the Western world. Therefore, detection and quantification of atherosclerotic disease is of paramount importance to monitor treatment and possible prevention of acute events. Vascular ultrasound is an excellent technique to assess the geometry of vessel walls and plaques. The high temporal as well as spatial resolution allows quantification of luminal area and plaque size and volume. While carotid arteries can be imaged non-invasively, scanning of coronary arteries requires invasive intravascular catheters. Both techniques have already demonstrated their clinical applicability. Using linear array technology, detection of disease as well as monitoring of pharmaceutical treatment in carotid arteries are feasible. Data acquired with intravascular ultrasound catheters have proved to be especially beneficial in understanding the development of atherosclerotic disease in coronary arteries. With the introduction of vascular elastography not only the geometry of plaques but also the risk for rupture of plaques might be identified. These so-called vulnerable plaques are frequently not flow-limiting and rupture of these plaques is responsible for the majority of cerebral and cardiac ischaemic events. Intravascular ultrasound elastography studies have demonstrated a high correlation between high strain and vulnerable plaque features, both ex vivo and in vivo. Additionally, pharmaceutical intervention could be monitored using this technique. Non-invasive vascular elastography has recently been developed for carotid applications by using compound scanning. Validation and initial clinical evaluation is currently being performed. Since abundance of vasa vasorum (VV) is correlated with vulnerable plaque development, quantification of VV might be a unique tool to even prevent this from happening. Using ultrasound contrast agents, it has been demonstrated that VV can be identified and quantified. Although far from routine clinical application, non-invasive and intravascular ultrasound VV imaging might pave the road to prevent atherosclerotic disease in an early phase. This paper reviews the conventional vascular ultrasound techniques as well as vascular ultrasound strain and vascular ultrasound VV imaging.
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Affiliation(s)
- Chris L. de Korte
- Clinical Physics Laboratory, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Hendrik H. G. Hansen
- Clinical Physics Laboratory, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Anton F. W. van der Steen
- Thoraxcentre Biomedical Engineering, ErasmusMC, Rotterdam, The Netherlands
- Interuniversity Cardiology Institute of The Netherlands, Utrecht, The Netherlands
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76
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Nguyen PN, Trinh Dang TT, Waton G, Vandamme T, Krafft MP. A Nonpolar, Nonamphiphilic Molecule Can Accelerate Adsorption of Phospholipids and Lower Their Surface Tension at the Air/Water Interface. Chemphyschem 2011; 12:2646-52. [DOI: 10.1002/cphc.201100425] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Indexed: 11/11/2022]
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77
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Kuenen MPJ, Mischi M, Wijkstra H. Contrast-ultrasound diffusion imaging for localization of prostate cancer. IEEE TRANSACTIONS ON MEDICAL IMAGING 2011; 30:1493-1502. [PMID: 21402509 DOI: 10.1109/tmi.2011.2125981] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Prostate cancer is the most prevalent form of cancer in western men. An accurate early localization of prostate cancer, permitting efficient use of modern focal therapies, is currently hampered by a lack of imaging methods. Several methods have aimed at detecting microvascular changes associated with prostate cancer with limited success by quantitative imaging of blood perfusion. Differently, we propose contrast-ultrasound diffusion imaging, based on the hypothesis that the complexity of microvascular changes is better reflected by diffusion than by perfusion characteristics. Quantification of local, intravascular diffusion is performed after transrectal ultrasound imaging of an intravenously injected ultrasound contrast agent bolus. Indicator dilution curves are measured with the ultrasound scanner resolution and fitted by a modified local density random walk model, which, being a solution of the convective diffusion equation, enables the estimation of a local, diffusion-related parameter. Diffusion parametric images obtained from five datasets of four patients were compared with histology data on a pixel basis. The resulting receiver operating characteristic (curve area = 0.91) was superior to that of any perfusion-related parameter proposed in the literature. Contrast-ultrasound diffusion imaging seems therefore to be a promising method for prostate cancer localization, encouraging further research to assess the clinical reliability.
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Affiliation(s)
- Maarten P J Kuenen
- Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
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78
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Watson KD, Hu X, Lai CY, Lindfors HA, Hu-Lowe DD, Tuthill TA, Shalinsky DR, Ferrara KW. Novel ultrasound and DCE-MRI analyses after antiangiogenic treatment with a selective VEGF receptor inhibitor. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:909-21. [PMID: 21531499 PMCID: PMC3198831 DOI: 10.1016/j.ultrasmedbio.2011.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 02/22/2011] [Accepted: 03/01/2011] [Indexed: 05/15/2023]
Abstract
We report a comparison between tumor perfusion estimates acquired using contrast-enhanced MRI and motion-corrected contrast-enhanced ultrasound before and after treatment with AG-028262, a potent vascular endothelial growth factor receptor tyrosine kinase inhibitor. Antiangiogenic activity was determined by assessing weekly ultrasound and MRI images of rats with bilateral hind flank mammary adenocarcinomas before and after treatment with AG-028262. Images were acquired with a spoiled gradient, 1.5 T magnetic resonance sequence and a destruction-replenishment ultrasound protocol. For ultrasound, a time to 80% contrast replenishment was calculated for each tumor voxel; for MR imaging, a measure of local flow rate was estimated from a linear fit of minimum to maximum intensities. AG-028262 significantly decreased tumor growth and increased the time required to replenish tumor voxels with an ultrasound contrast agent from 2.66 to 4.54 s and to fill with an MR contrast agent from 29.5 to 50.8 s. Measures of flow rate derived from MRI and ultrasound demonstrated a positive linear correlation of r2 = 0.86.
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Affiliation(s)
- Katherine D Watson
- Department of Biomedical Engineering, University of California, Davis, CA 95327, USA
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79
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Vos HJ, Goertz DE, van der Steen AFW, de Jong N. Parametric array technique for microbubble excitation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2011; 58:924-934. [PMID: 21622048 DOI: 10.1109/tuffc.2011.1893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study investigates the use of an acoustic parametric array as a means for microbubble excitation. The excitation wave is generated during propagation in a nonlinear medium of two high-frequency carrier waves, whereby the frequency of the excitation wave is the difference frequency of the carrier waves. Carrier waves of around 10 and 25 MHz are used to generate low-frequency waves between 0.5 and 3.5 MHz at amplitudes in the range of 25 to 80 kPa in water. We demonstrate with high-speed camera observations that it is possible to induce microbubble oscillations with the low frequency signal arising from the nonlinear propagation process. As an application, we determined the resonance frequency of Definity contrast agent microbubbles with radius ranging from 1.5 to 5 μm by sweeping the difference frequency in the range from 0.5 to 3.5 MHz.
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Affiliation(s)
- Hendrik J Vos
- Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands
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80
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Chan ESY, Patel AR, Larchian WA, Heston WD. In vivo targeted contrast enhanced micro-ultrasound to measure intratumor perfusion and vascular endothelial growth factor receptor 2 expression in a mouse orthotopic bladder cancer model. J Urol 2011; 185:2359-65. [PMID: 21511281 DOI: 10.1016/j.juro.2011.02.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Indexed: 11/25/2022]
Abstract
PURPOSE We evaluated the feasibility of using targeted contrast enhanced micro-ultrasound imaging to assess intratumor perfusion and vascular endothelial growth factor receptor 2 expressions in a mouse orthotopic bladder cancer model. MATERIALS AND METHODS We created an orthotopic mouse model by implanting MBT-2 murine bladder cancer cell lines in the bladder of syngeneic C3H/He mice (Jackson Laboratory, Bar Harbor, Maine). Successful tumor implantation was confirmed by transabdominal micro-ultrasound imaging on post-implantation day 11. Contrast enhanced micro-ultrasound imaging was done on days 14 and 21. Vascular endothelial growth factor receptor 2 targeted contrast agent was prepared by adding biotinylated anti-vascular endothelial growth factor receptor 2 monoclonal antibodies to streptavidin coated microbubbles. The targeted contrast agents were injected via the retro-orbital route. We quantified intratumor perfusion, vascular endothelial growth factor receptor 2 endothelial expression and blood volume in real time. RESULTS In the initial study intratumor perfusion data and vascular endothelial growth factor receptor 2 expression could only be measured in 10 of 14 mice (71%) due to motion artifact. We modified our technique by applying an elastic band over the lower abdomen to minimize body wall movement. After the modification complete images were acquired in all mice at 2 consecutive imaging sessions. Measurements were made of intratumor perfusion and in vivo vascular endothelial growth factor receptor 2 expression. No adverse effects occurred due to anesthesia or the ultrasound contrast agent. CONCLUSIONS Targeted contrast enhanced micro-ultrasound imaging enables investigators to detect and monitor vascular changes in orthotopic bladder tumors. It may be useful for direct, noninvasive, in vivo evaluation of novel anti-angiogenesis therapeutic agents. With the modified technique target enhanced contrast ultrasound can be applied in an orthotopic bladder cancer model.
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Affiliation(s)
- Eddie S Y Chan
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China
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81
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Faez T, Goertz D, De Jong N. Characterization of Definity™ ultrasound contrast agent at frequency range of 5-15 MHz. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:338-42. [PMID: 21257093 DOI: 10.1016/j.ultrasmedbio.2010.11.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 11/10/2010] [Accepted: 11/23/2010] [Indexed: 05/11/2023]
Abstract
The status of vasa vasorum, which can be imaged using ultrasound contrast agents, is an indication for the progression of atherosclerosis. The preferred ultrasound frequency for this purpose is between 5 and 15 MHz. Therefore, it is essential to have knowledge about the acoustic properties of microbubbles such as elasticity and viscosity to be able to implement the current models for lipid encapsulated microbubbles developed for frequencies used in precordial imaging. In this study, the shell parameters, stiffness S(p) and friction S(f), of Definity™ microbubbles have been calculated at frequency range of 5-15 MHz by comparing the theoretical modeling of acoustic bubble response and experimental measurements. Derived parameters are in good agreement with previous estimations on SonoVue™ and Sonazoid™ contrast agent. However, the value of S(f) is higher than previously estimated for Definity™ between 12-28 MHz.
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Affiliation(s)
- Telli Faez
- Biomedical Engineering Thoraxcentre, Erasmus Medical Centre, Rotterdam, The Netherlands.
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82
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Cerroni B, Chiessi E, Margheritelli S, Oddo L, Paradossi G. Polymer Shelled Microparticles for a Targeted Doxorubicin Delivery in Cancer Therapy. Biomacromolecules 2011; 12:593-601. [DOI: 10.1021/bm101207k] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Barbara Cerroni
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Ester Chiessi
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Silvia Margheritelli
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Letizia Oddo
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
| | - Gaio Paradossi
- Dipartimento di Scienze e Tecnologie Chimiche, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy
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83
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New advances in noninvasive imaging of the carotid artery: CIMT, contrast-enhanced ultrasound, and vasa vasorum. Curr Cardiol Rep 2010; 12:497-502. [PMID: 20799001 DOI: 10.1007/s11886-010-0139-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Carotid ultrasound measurement of carotid intima-media thickness (CIMT) and detection of plaques is a useful method to better assess cardiovascular disease risk status, especially in those at intermediate risk. We discuss the use CIMT and other emerging techniques such as contrast-enhanced carotid ultrasound imaging in the evaluation of the carotid artery and its value in cardiovascular disease.
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84
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Cosgrove D, Lassau N. Imaging of perfusion using ultrasound. Eur J Nucl Med Mol Imaging 2010; 37 Suppl 1:S65-85. [PMID: 20640418 DOI: 10.1007/s00259-010-1537-7] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ultrasound can be used to image perfusion in two ways: the traditional one using Doppler and the more recent using microbubble contrast agents. Doppler is simple to use and inexpensive but is limited to larger vessels with faster flow rates. It cannot interrogate the microvasculature because bulk tissue movement is faster than capillary flow. It has been used for liver and tumour flow. Contrast studies are much richer and can assess both the macro- and microcirculation. One approach analyses the time-intensity curves in a region of interest, e.g. a tumour, myocardium, brain, following bolus i.v. injection. Another approach measures the time taken for the microbubbles to cross a vascular bed of interest. These arrival times can be useful for the liver in both diffuse and focal diseases and for the kidney. Features derived from time-intensity curves following bolus i.v. injections of microbubbles form sensitive early indicators of the vascular response of tumours to antivascular drugs. This approach, known as dynamic contrast-enhanced ultrasound (DCE-US), has been accepted as a valid technique for monitoring tumour response by several authorities.
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Affiliation(s)
- David Cosgrove
- Imaging Sciences Department, Imperial College, Hammersmith Hospital, London, UK.
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85
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Giannarelli C, Ibanez B, Cimmino G, Garcia Ruiz JM, Faita F, Bianchini E, Zafar MU, Fuster V, Garcia MJ, Badimon JJ. Contrast-Enhanced Ultrasound Imaging Detects Intraplaque Neovascularization in an Experimental Model of Atherosclerosis. JACC Cardiovasc Imaging 2010; 3:1256-64. [DOI: 10.1016/j.jcmg.2010.09.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 09/16/2010] [Indexed: 11/28/2022]
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86
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Sijl J, Dollet B, Overvelde M, Garbin V, Rozendal T, de Jong N, Lohse D, Versluis M. Subharmonic behavior of phospholipid-coated ultrasound contrast agent microbubbles. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2010; 128:3239-52. [PMID: 21110619 DOI: 10.1121/1.3493443] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Coated microbubbles, unlike tissue are able to scatter sound subharmonically. Therefore, the subharmonic behavior of coated microbubbles can be used to enhance the contrast in ultrasound contrast imaging. Theoretically, a threshold amplitude of the driving pressure can be calculated above which subharmonic oscillations of microbubbles are initiated. Interestingly, earlier experimental studies on coated microbubbles demonstrated that the threshold for these bubbles is much lower than predicted by the traditional linear viscoelastic shell models. This paper presents an experimental study on the subharmonic behavior of differently sized individual phospholipid coated microbubbles. The radial subharmonic response of the microbubbles was recorded with the Brandaris ultra high-speed camera as a function of both the amplitude and the frequency of the driving pulse. Threshold pressures for subharmonic generation as low as 5 kPa were found near a driving frequency equal to twice the resonance frequency of the bubble. An explanation for this low threshold pressure is provided by the shell buckling model proposed by Marmottant et al. [J. Acoust. Soc. Am. 118, 3499-3505 (2005)]. It is shown that the change in the elasticity of the bubble shell as a function of bubble radius as proposed in this model, enhances the subharmonic behavior of the microbubbles.
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Affiliation(s)
- Jeroen Sijl
- Physics of Fluids Group and MIRA Institute of Biomedical Engineering and Technical Medicine, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
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87
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Staub D, Partovi S, Schinkel AFL, Coll B, Uthoff H, Aschwanden M, Jaeger KA, Feinstein SB. Correlation of carotid artery atherosclerotic lesion echogenicity and severity at standard US with intraplaque neovascularization detected at contrast-enhanced US. Radiology 2010; 258:618-26. [PMID: 20971776 DOI: 10.1148/radiol.10101008] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To correlate echogenicity and severity of atherosclerotic carotid artery lesions at standard ultrasonography (US) with the degree of intraplaque neovascularization at contrast material-enhanced (CE) US. MATERIALS AND METHODS This HIPAA-compliant study was approved by the local ethics committee, and all patients provided informed consent. A total of 175 patients (113 [65%] men, 62 [35%] women; mean age, 67 years ± 10 [standard deviation]) underwent standard and CE US of the carotid artery. Lesion echogenicity (class I to IV), degree of stenosis, and maximal lesion thickness were evaluated for each documented atherosclerotic lesion. The degree of intraplaque neovascularization at CE US was categorized as absent (grade 1), moderate (grade 2), or extensive (grade 3). Correlation of neovascularization with echogenicity, degree of stenosis, and maximal lesion thickness was made by using Spearman ρ and χ(2) test for trend. RESULTS In a total of 293 atherosclerotic lesions, echogenicity was inversely correlated with grade of intraplaque neovascularization (ρ = -0.199, P < .001). More echolucent lesions had a higher degree of neovascularization compared with more echogenic ones (P < .001). The degree of stenosis was significantly correlated with grade of intraplaque neovascularization (ρ = 0.157, P = .003). Lesions with higher degree of stenosis had higher grade of neovascularization (P = .008), and maximal lesion thickness increased with the grade of neovascularization (P < .001) and was significantly correlated with grade of neovascularization (ρ = 0.233, P < .001). CONCLUSION Neovascularization visualized with CE US correlates with lesion severity and with morphologic features of plaque instability, contributing to the concept that more vulnerable plaques are more likely to have a greater degree of neovascularization. Therefore, CE US may be a valuable tool for further risk stratification of echolucent atherosclerotic lesions and carotid artery stenosis of different degrees. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10101008/-/DC1.
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Affiliation(s)
- Daniel Staub
- Department of Internal Medicine, Section of Cardiology, Rush University Medical Center, Chicago, Ill, USA.
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88
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Maresca D, Emmer M, van Neer PLMJ, Vos HJ, Versluis M, Muller M, de Jong N, van der Steen AFW. Acoustic sizing of an ultrasound contrast agent. ULTRASOUND IN MEDICINE & BIOLOGY 2010; 36:1713-1721. [PMID: 20850027 DOI: 10.1016/j.ultrasmedbio.2010.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 06/03/2010] [Accepted: 06/17/2010] [Indexed: 05/29/2023]
Abstract
Because the properties of ultrasound contrast agent populations after administration to patients are largely unknown, methods able to study them noninvasively are required. In this study, we acoustically performed a size distribution measurement of the ultrasound contrast agent Definity(®). Single lipid-shelled microbubbles were insonified at 25 MHz, which is considerably higher than their resonance frequency, so that their acoustic responses depended on their geometrical cross sections only. We calculated the size of each microbubble from their measured backscattered pressures. The acoustic size measurements were compared with optical reference size measurements to test their accuracy. Our acoustic sizing method was applied to 88 individual Definity(®) bubbles to derive a size distribution of this agent. The size distribution obtained acoustically showed a mean diameter (2.5 μm) and a standard deviation (0.9 μm) in agreement within 8% with the optical reference measurement. At 25 MHz, this method can be applied to bubble sizes larger than 1.2 μm in diameter. It was observed that similar sized bubbles can give different responses (up to a factor 1.5), probably because of shell differences. These limitations should be taken into account when implementing the method in vivo. This acoustic sizing method has potential for estimating the size distribution of an ultrasound contrast agent noninvasively.
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Affiliation(s)
- David Maresca
- Biomedical Engineering Thoraxcentre, Erasmus University Medical Centre, Rotterdam, The Netherlands.
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89
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ten Kate GL, Sijbrands EJG, Valkema R, ten Cate FJ, Feinstein SB, van der Steen AFW, Daemen MJAP, Schinkel AFL. Molecular imaging of inflammation and intraplaque vasa vasorum: a step forward to identification of vulnerable plaques? J Nucl Cardiol 2010; 17:897-912. [PMID: 20552308 PMCID: PMC2940038 DOI: 10.1007/s12350-010-9263-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Current developments in cardiovascular biology and imaging enable the noninvasive molecular evaluation of atherosclerotic vascular disease. Intraplaque neovascularization sprouting from the adventitial vasa vasorum has been identified as an independent predictor of intraplaque hemorrhage and plaque rupture. These intraplaque vasa vasorum result from angiogenesis, most likely under influence of hypoxic and inflammatory stimuli. Several molecular imaging techniques are currently available. Most experience has been obtained with molecular imaging using positron emission tomography and single photon emission computed tomography. Recently, the development of targeted contrast agents has allowed molecular imaging with magnetic resonance imaging, ultrasound and computed tomography. The present review discusses the use of these molecular imaging techniques to identify inflammation and intraplaque vasa vasorum to identify vulnerable atherosclerotic plaques at risk of rupture and thrombosis. The available literature on molecular imaging techniques and molecular targets associated with inflammation and angiogenesis is discussed, and the clinical applications of molecular cardiovascular imaging and the use of molecular techniques for local drug delivery are addressed.
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Affiliation(s)
- Gerrit L. ten Kate
- Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Cardiology, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Eric J. G. Sijbrands
- Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Roelf Valkema
- Department of Nuclear Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Folkert J. ten Cate
- Department of Cardiology, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Steven B. Feinstein
- Section of Cardiology, Department of Internal Medicine, Rush University Medical Center, Chicago, IL USA
| | | | - Mat J. A. P. Daemen
- Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Arend F. L. Schinkel
- Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
- Department of Cardiology, Thoraxcenter, Erasmus Medical Center, Rotterdam, The Netherlands
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90
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Staub D, Schinkel AF, Coll B, Coli S, van der Steen AF, Reed JD, Krueger C, Thomenius KE, Adam D, Sijbrands EJ, ten Cate FJ, Feinstein SB. Contrast-Enhanced Ultrasound Imaging of the Vasa Vasorum. JACC Cardiovasc Imaging 2010; 3:761-71. [PMID: 20633855 DOI: 10.1016/j.jcmg.2010.02.007] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 01/20/2010] [Accepted: 02/18/2010] [Indexed: 10/19/2022]
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91
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Contrast-enhanced ultrasound detection and treatment guidance in a renal transplant patient with renal cell carcinoma. Ultrasound Q 2010; 25:171-3. [PMID: 19956049 DOI: 10.1097/ruq.0b013e3181b4f9cf] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Contrast-enhanced ultrasonography (CEUS) is an imaging modality that shows promise in the detection and characterization of renal masses, as well as treatment through CEUS-guided percutaneous radiofrequency ablation. These techniques may be especially valuable in challenging patients who cannot tolerate traditional contrast agents, such as those with diminished renal function, and those who cannot tolerate more invasive surgical treatment. The following case report details an incidence of renal cell carcinoma in a renal transplant patient whose tumor was diagnosed with CEU and successfully treated with CEUS-guided percutaneous RFA.
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92
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Zacharatos H, Hassan AE, Qureshi AI. Intravascular ultrasound: principles and cerebrovascular applications. AJNR Am J Neuroradiol 2010; 31:586-97. [PMID: 20133387 DOI: 10.3174/ajnr.a1810] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Intravascular sonography is a valuable tool for the morphologic assessment of coronary atherosclerosis and the effect of pharmacologic and nonpharmacologic interventions on the progression or stabilization of atherosclerosis. An analysis of the different modes, applications, and limitations is provided on the basis of review of existing data from multiple clinical case studies, trials, and mechanistic studies. Intravascular sonography has been used to assess the outcomes of different percutaneous interventions, including angioplasty and stent implantation, and to provide detailed characterization of atherosclerotic lesions, aneurysms, and dissections within the cerebrovascular circulation. Evolution of intravascular sonographic technology has led to the development of more sophisticated diagnostic tools such as color-flow, virtual histology, and integrated backscatter intravascular sonography. The technologic advancement in intravascular sonography has the potential of providing more accurate information prior, during, and after a medical or endovascular intervention. Continued assessment of this diagnostic technique in both the intracranial and extracranial circulation will lead to increased use in clinical practice with the intent to improve outcomes.
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Affiliation(s)
- H Zacharatos
- Zeenat Qureshi Stroke Research Center, Department of Neurology, University of Minnesota, Minneapolis, 55455, USA
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93
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Rossi S, Waton G, Krafft MP. Phospholipid-coated gas bubble engineering: key parameters for size and stability control, as determined by an acoustical method. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:1649-1655. [PMID: 20099916 DOI: 10.1021/la9025987] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have recently reported the sampling of differently sized monomodal populations of microbubbles from a polydisperse lipid-coated bubble preparation. The microbubbles were coated with dimyristoylphosphatidylcholine (DMPC) and stabilized by perfluorohexane (PFH). Such microbubbles are useful as contrast agents and, potentially, for oxygen, drug, and gene delivery and as therapeutic devices. Monomodal populations of small bubbles (approximately 1.6 microm in radius) and large bubbles (approximately 5.4 microm) have been obtained, as assessed by acoustical measurement, static light scattering, and optical microscopy. In this paper, we have determined the influence of various preparation parameters on the initial size characteristics (mean radius and radii distribution) of the microbubbles and on their stability upon time. The bubble size was determined acoustically, with a homemade acoustic setup equipped with a low-power emitter, to avoid altering the bubble stability. We have focused on the effects of the bubble flotation time during the fractionation process and on the DMPC concentration. PFH was indispensable for obtaining stable bubbles. The nature of the buffer [Isoton II vs N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES)] used as the continuous phase did not significantly impact the bubble characteristics and stability. In both buffers, the half-lives of small bubbles (approximately 1.6 microm in radius in Isoton II and approximately 2.1 microm in HEPES) were found to be longer than those of larger ones (approximately 5.4 and approximately 5.9 microm in Isoton II and HEPES, respectively). The bubble stability study revealed that in both buffers, the average radius of the population of large bubbles progressively increased with time. On the other hand, the average radius of the population of small bubbles decreased slightly in Isoton II and remained constant in HEPES. This suggests that the dissolution behavior of small and large bubbles is governed by different mechanisms.
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Affiliation(s)
- Simona Rossi
- Systèmes Organisés Fluores à Finalités Thérapeutiques, Université de Strasbourg, Institut Charles Sadron (CNRS), 23 rue du Loess, 67034 Strasbourg Cedex 2, France
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94
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Staub D, Patel MB, Tibrewala A, Ludden D, Johnson M, Espinosa P, Coll B, Jaeger KA, Feinstein SB. Vasa Vasorum and Plaque Neovascularization on Contrast-Enhanced Carotid Ultrasound Imaging Correlates With Cardiovascular Disease and Past Cardiovascular Events. Stroke 2010; 41:41-7. [PMID: 19910551 DOI: 10.1161/strokeaha.109.560342] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background and Purpose—
Histological data associate proliferation of adventitial vasa vasorum and intraplaque neovascularization with vulnerable plaques represented by symptomatic vascular disease. In this observational study, the presence of carotid intraplaque neovascularization and adventitial vasa vasorum were correlated with the presence and occurrence of cardiovascular disease (CVD) and events (CVE).
Methods—
The contrast-enhanced carotid ultrasound examinations of 147 subjects (mean age 64±11 years, 61% male) were analyzed for the presence of intraluminal plaque, plaque neovascularization (Grade 1=absent; Grade 2=present), and degree of adventitial vasa vasorum (Grade 1=absent, Grade 2=present). These observations were correlated with preexisting cardiovascular risk factors, presence of CVD, and history of CVE (myocardial infarction and transient ischemic attack/stroke).
Results—
The presence of intraluminal carotid plaque was directly correlated to cardiovascular risk factors, CVD, and CVE (
P
<0.05). Adventitial vasa vasorum Grade 2 was associated with significant more subjects with CVD than vasa vasorum Grade 1 (73 versus 54%,
P
=0.029). Subjects with intraplaque neovascularization Grade 2 had significantly more often a history of CVE than subjects with intraplaque neovascularization Grade 1 (38 versus 20%,
P
=0.031). Multivariate logistic regression analysis revealed that presence of plaque was significantly associated with CVD (odds ratio 4.7, 95% CI 1.6 to 13.8) and intraplaque neovascularization grade 2 with CVE (odds ratio 4.0, 95% CI 1.3 to 12.6).
Conclusion—
The presence and degree of adventitial vasa vasorum and plaque neovascularization were directly associated with CVD and CVE in a retrospective study of 147 patients undergoing contrast-enhanced carotid ultrasound.
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Affiliation(s)
- Daniel Staub
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - Mita B. Patel
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - Anjan Tibrewala
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - David Ludden
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - Mahala Johnson
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - Paul Espinosa
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - Blai Coll
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - Kurt A. Jaeger
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
| | - Steven B. Feinstein
- From the Department of Internal Medicine, Section of Cardiology (D.S., M.B.P., A.T., D.L., M.J., P.E., S.B.F.), Rush University Medical Center, Chicago, Ill; Unitat de Diagnòstic i Tractament de Malalties Aterotrombòtiques (UDETMA) (B.C.), Hospital Arnau de Vilanova, Lleida, Spain; and the Department of Angiology (K.A.J.), University Hospital, Basel, Switzerland
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95
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Feinstein SB, Coll B, Staub D, Adam D, Schinkel AFL, ten Cate FJ, Thomenius K. Contrast enhanced ultrasound imaging. J Nucl Cardiol 2010; 17:106-15. [PMID: 19921346 DOI: 10.1007/s12350-009-9165-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Steven B Feinstein
- Rush University Medical Center, Suite 1015 Jelke, 1653 West Congress Parkway, Chicago, IL 60612, USA.
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96
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Hudson JM, Karshafian R, Burns PN. Quantification of flow using ultrasound and microbubbles: a disruption replenishment model based on physical principles. ULTRASOUND IN MEDICINE & BIOLOGY 2009; 35:2007-20. [PMID: 19822390 DOI: 10.1016/j.ultrasmedbio.2009.06.1102] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 06/22/2009] [Accepted: 06/26/2009] [Indexed: 05/19/2023]
Abstract
Contrast-enhanced ultrasound (CEUS) is a promising clinical tool capable of noninvasively quantifying flow and relative vascular volume within the microcirculation. Quantification can be performed by recording the replenishment intensity time course of the imaging plane after the local disruption of agent during a constant infusion. Traditional analyses of the time-intensity curves have relied on mathematical functions (e.g., mono-exponential) that fail to consider the underlying physical principles of the flow system and the influence of the measurement device. In reality, the time-intensity curve reflects the hemodynamics and morphology of the vascular system being measured, the ultrasound field distribution and microbubble properties. We introduce a general analytic disruption replenishment model that attempts to account for these parameters and compare its performance to the established model in a flow phantom. Specifically, the proposed model incorporates the hemodynamic properties of the flow system (velocity distribution and vascular cross section); includes the elevation and axial plane pressure distributions; and accounts for the distinct high and low mechanical index (MI) disruption and detection boundaries. In addition, we demonstrated the importance of the ultrasound beam profile for accurate velocity quantification. It was shown that velocity estimates vary by up to 56% if the depth-dependent elevation thickness is not properly accounted for. Compared with the currently accepted mono-exponential model, the presented formalism was shown to be more robust in the presence of simulated motion artifacts and demonstrated better agreement in both the quality of the fit and estimation of velocity (approximately 3 to 10% vs. 90% error) for the same flow and acoustic conditions.
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Affiliation(s)
- John M Hudson
- Department of Medical Biophysics, University of Toronto, Toronto, Canada; and Sunnybrook Health Sciences Centre, Toronto, Canada.
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97
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Sirsi S, Borden M. Microbubble Compositions, Properties and Biomedical Applications. BUBBLE SCIENCE ENGINEERING AND TECHNOLOGY 2009; 1:3-17. [PMID: 20574549 PMCID: PMC2889676 DOI: 10.1179/175889709x446507] [Citation(s) in RCA: 378] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Over the last decade, there has been significant progress towards the development of microbubbles as theranostics for a wide variety of biomedical applications. The unique ability of microbubbles to respond to ultrasound makes them useful agents for contrast ultrasound imaging, molecular imaging, and targeted drug and gene delivery. The general composition of a microbubble is a gas core stabilized by a shell comprised of proteins, lipids or polymers. Each type of microbubble has its own unique advantages and can be tailored for specialized functions. In this review, different microbubbles compositions and physiochemical properties are discussed in the context of current progress towards developing novel constructs for biomedical applications, with specific emphasis on molecular imaging and targeted drug/gene delivery.
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Affiliation(s)
- Shashank Sirsi
- Department of Chemical Engineering, Columbia University, 500 W 120 ST, New York, NY 10027, Phone: 212-854-7279
| | - Mark Borden
- Department of Chemical Engineering, Columbia University, 500 W 120 ST, New York, NY 10027, Phone: 212-854-6955, Fax: 212-854-3044
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98
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Wink MH, Wijkstra H, De La Rosette JJMCH, Grimbergen CA. Ultrasound imaging and contrast agents: A safe alternative to MRI? MINIM INVASIV THER 2009; 15:93-100. [PMID: 16754192 DOI: 10.1080/13645700600674252] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Microbubble contrast media are used to enhance ultrasound images. Because ultrasound is a real-time investigation, contrast-enhanced ultrasound offers possibilities for perfusion imaging. This review is conducted to evaluate the safety of contrast-enhanced ultrasound and its possible role in medical imaging. The safety of diagnostic ultrasound is still an important field of research. The wanted and unwanted effects of ultrasound and microbubble contrast media as well as the effects of ultrasound on these microbubbles are described. Furthermore, some of the possible applications and indications of contrast-enhanced ultrasound will be discussed. The shared advantages of MRI and ultrasound are the use of non-ionizing radiation and non-nephrotoxic contrast media. From this review it can be concluded that, for certain indications, contrast enhanced ultrasound could be a safe alternative to MRI and a valuable addition to medical imaging.
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Affiliation(s)
- Margot H Wink
- Department of Urology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
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99
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Cosgrove D, Lassau N. [Assessment of tumour angiogenesis using contrast-enhanced ultrasound]. ACTA ACUST UNITED AC 2009; 90:156-64. [PMID: 19212283 DOI: 10.1016/s0221-0363(09)70094-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Microbubbles are useful for imaging tumour angiogenesis and relatively crude forms of this approach are now routinely used for subjective diagnosis, especially in the liver. More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves and have shown great promise in revealing effective tumour response to anti-angiogenic drugs in humans before tumour shrinkage occurs. These are beginning to be accepted into clinical practice. In the long term, targeted microbubbles for molecular imaging and eventually for directed anti-tumour therapy are expected to be tested.
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Affiliation(s)
- D Cosgrove
- Imaging Sciences Department, Imperial College, Hammersmith Hospital, London W120HS, UK.
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100
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Xiong L, Deng YB, Zhu Y, Liu YN, Bi XJ. Correlation of carotid plaque neovascularization detected by using contrast-enhanced US with clinical symptoms. Radiology 2009; 251:583-9. [PMID: 19304920 DOI: 10.1148/radiol.2512081829] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE To determine the correlation between the degree of plaque enhancement with contrast agent microbubbles and clinical symptoms in patients with carotid atherosclerotic plaque. MATERIALS AND METHODS The study was approved by the hospital ethical committee, and informed consent was obtained from all patients. One hundred four patients (83 men: mean age, 64 years +/- 9 [standard deviation]; 21 women: mean age, 61 years +/- 10) with carotid plaques were studied with standard and contrast material-enhanced ultrasonography (US). Contrast enhancement in the plaque was evaluated with visual interpretation and quantitative analysis. RESULTS Among the 104 patients, 35 (34%) had transient ischemic attack and/or cerebrovascular ischemic stroke. Plaque enhancement was found in 28 (80%) of 35 symptomatic patients and in 21 (30%) of 69 asymptomatic patients (P < .001). Enhanced intensity in the plaque (13.9 dB +/- 6.4) and the ratio of enhanced intensity in the plaque to that in the lumen of the carotid artery (0.54 +/- 0.23) in symptomatic patients were significantly greater than those in asymptomatic patients (8.8 dB +/- 5.2 [P < .001] and 0.33 +/- 0.19 [P < .001], respectively). Sensitivity and specificity were 74% and 62%, respectively, for enhanced intensity in the plaque (cutoff value, 10.0 dB) and 74% and 75%, respectively, for ratio of enhanced intensity in the plaque to that in the lumen of the carotid artery (cutoff value, 0.46). CONCLUSION Symptomatic patients had more intense contrast agent enhancement in the plaque than asymptomatic patients, suggesting that contrast-enhanced carotid US may be used for plaque risk stratification.
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Affiliation(s)
- Li Xiong
- Department of Medical Ultrasound, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan 430030, P. R. China
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