Cardiovascular Molecular Imaging

2015 ◽  
Author(s):  
Alan R. Morrison ◽  
Joseph C. Wu ◽  
Mehran M. Sadeghi
Keyword(s):  
Molecular Imaging ◽  
Photoacoustic Imaging ◽  
Nuclear Imaging ◽  
Biological Information ◽  
Novel Approach ◽  
Novel Therapeutic Strategies ◽  
Pathologic Processes ◽  
Cardiovascular Molecular Imaging ◽  
Accurate Quantification

Cardiovascular molecular imaging is a relatively young but rapidly expanding discipline that consists of a biologically-targeted approach to the assessment of physiologic and pathologic processes in vivo. This novel approach to imaging involves the integration of multiple disciplines such as cell and molecular biology, chemistry, and imaging sciences. The ultimate goal is quantitative assessment of cardiovascular processes at the cellular and molecular level, moving beyond traditional diagnostic information, in order to guide individually tailored therapy. In fact, it is likely that specific approaches to molecular imaging will be developed in tandem with the development of novel therapeutic strategies. Recent advances in probe development and imaging systems have contributed to evolution of molecular imaging toward clinical translational. These include technological progress in traditional imaging platforms; along with the emergence of newer imaging modalities such as photoacoustic imaging. In addition, hybrid imaging (e.g. nuclear imaging with CT or MRI) has the potential for improved spatial localization, and more accurate quantification by coupling anatomic and biological information. In addition to potential clinical applications that address existing diagnostic gaps in cardiovascular medicine, molecular imaging allows for unique approaches to studying pathophysiology. This chapter is intended to provide an overview of the state of the art in cardiovascular molecular imaging, highlighting how it may improve the management of major cardiovascular diseases.

scholarly journals Photoacoustic reporter genes for noninvasive molecular imaging and theranostics

2020 ◽  
Vol 13 (03) ◽  
pp. 2030005
Author(s):  
Zhao Lei ◽  
Yun Zeng ◽  
Xiaofen Zhang ◽  
Xiaoyong Wang ◽  
Gang Liu
Keyword(s):  
Molecular Imaging ◽  
Fluorescent Proteins ◽  
Photoacoustic Imaging ◽  
High Sensitivity ◽  
Reporter Genes ◽  
Biological Processes ◽  
Deep Tissue ◽  
Potential Applications ◽  
Improved Performance

Noninvasive molecular imaging makes the observation and comprehensive understanding of complex biological processes possible. Photoacoustic imaging (PAI) is a fast evolving hybrid imaging technology enabling in vivo imaging with high sensitivity and spatial resolution in deep tissue. Among the various probes developed for PAI, genetically encoded reporters attracted increasing attention of researchers, which provide improved performance by acquiring images of a PAI reporter gene’s expression driven by disease-specific enhancers/promoters. Here, we present a brief overview of recent studies about the existing photoacoustic reporter genes (RGs) for noninvasive molecular imaging, such as the pigment enzyme reporters, fluorescent proteins and chromoproteins, photoswitchable proteins, including their properties and potential applications in theranostics. Furthermore, the challenges that PAI RGs face when applied to the clinical studies are also examined.

scholarly journals In Vitro Evaluation of Radiolabeled Amphotericin B for Molecular Imaging of Mold Infections

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
Lukas Page ◽  
Andrew J. Ullmann ◽  
Fabian Schadt ◽  
Sebastian Wurster ◽  
Samuel Samnick
Keyword(s):  
Molecular Imaging ◽  
Amphotericin B ◽  
Invasive Pulmonary Aspergillosis ◽  
Nuclear Imaging ◽  
Molecular Probes ◽  
Content Type ◽  
Diagnostic Potential ◽  
Gallium 68

ABSTRACT Invasive pulmonary aspergillosis and mucormycosis are life-threatening complications in immunocompromised patients. A rapid diagnosis followed by early antifungal treatment is essential for patient survival. Given the limited spectrum of biomarkers for invasive mold infections, recent studies have proposed the use of radiolabeled siderophores or antibodies as molecular probes to increase the specificity of radiological findings by nuclear imaging modalities. While holding enormous diagnostic potential, most of the currently available molecular probes are tailored to the detection of Aspergillus species, and their cost-intensive and sophisticated implementation restricts their accessibility at less specialized centers. In order to develop cost-efficient and broadly applicable tracers for pulmonary mold infections, this study established streamlined and high-yielding protocols to radiolabel amphotericin B (AMB) with the gamma emitter technetium-99m (99mTc-AMB) and the positron emitter gallium-68 (68Ga-AMB). The radiochemical purity of the resulting tracers consistently exceeded 99%, and both probes displayed excellent stability in human serum (>98% after 60 to 240 min at 37°C). The uptake kinetics by representative mold pathogens were assessed in an in vitro Transwell assay using infected endothelial cell layers. Both tracers accumulated intensively and specifically in Transwell inserts infected with Aspergillus fumigatus, Rhizopus arrhizus, and other clinically relevant mold pathogens compared with their accumulation in uninfected inserts and inserts infected with bacterial controls. Inoculum-dependent enrichment was confirmed by gamma counting and autoradiographic imaging. Taken together, this pilot in vitro study proposes 99mTc-AMB and 68Ga-AMB to be facile, stable, and specific probes, meriting further preclinical in vivo evaluation of radiolabeled amphotericin B for molecular imaging in invasive mycoses.

scholarly journals Molecular imaging perspectives

2005 ◽  
Vol 2 (3) ◽  
pp. 133-144 ◽  
Author(s):  
Paul J Cassidy ◽  
George K Radda
Keyword(s):  
Molecular Imaging ◽  
Contrast Agents ◽  
Physical Science ◽  
Life Science ◽  
Interdisciplinary Collaboration ◽  
Nuclear Imaging ◽  
Imaging Modalities ◽  
Molecular Events ◽  
Biological Target

Molecular imaging is an emerging technology at the life science/physical science interface which is set to revolutionize our understanding and treatment of disease. The tools of molecular imaging are the imaging modalities and their corresponding contrast agents. These facilitate interaction with a biological target at a molecular level in a number of ways. The diverse nature of molecular imaging requires knowledge from both the life and physical sciences for its successful development and implementation. The aim of this review is to introduce the subject of molecular imaging from both life science and physical science perspectives. However, we will restrict our coverage to the prominent in vivo molecular imaging modalities of magnetic resonance imaging, optical imaging and nuclear imaging. The physical basis of these imaging modalities, the use of contrast agents and the imaging parameters of sensitivity, temporal resolution and spatial resolution are described. Then, the specificity of contrast agents for targeting and sensing molecular events, and some applications of molecular imaging in biology and medicine are given. Finally, the diverse nature of molecular imaging and its reliance on interdisciplinary collaboration is discussed.

Abstract 804: Noninvasive Integrated SPECT/CT Molecular Imaging of Activated Factor XIII Activity in Thrombosis

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Farouc A Jaffer ◽  
Jose L Figueiredo ◽  
Gregory Wojtkiewicz ◽  
Hanwen Zhang ◽  
Purvish Patel ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Human Plasma ◽  
Half Life ◽  
Factor Xiii ◽  
Control Agent ◽  
Isotropic Resolution ◽  
Novel Approach ◽  
Imaging Strategy

Background : Activated factor XIII (FXIIIa) is a blood transglutaminase that mediates fibrinolytic resistance and is a hallmark of acute thrombi. Noninvasive molecular imaging of FXIIIa may offer a novel approach to identify acute thrombi and to gauge fibrinolytic resistance in vivo. Here we developed and validated a FXIIIa thrombosis imaging strategy using noninvasive integrated SPECT/CT. Methods: A FXIIIa-targeted peptide agent (F13) was synthesized using NQEQVSPLTLLK chelated to DOTA and then labeled with 111 InCl 3 . A control agent (C13, 111 In-NAEQVSPLTLLK) was analogously synthesized. In vitro validation of the F13 agent was performed in human plasma clots. Next, the in vivo blood-half life of F13 was determined in mice (n=4). In vivo thrombosis studies (n=15 mice) were then performed using 10% ferric chloride jugular venous thrombi aged 1 hour or 16 hours. Mice were intravenously injected with 200 μCi of F13 or C13. After 4 hours, mice underwent integrated CT angiography (72 μm isotropic resolution) and SPECT imaging (32 minute acquisition). In situ thrombi were then resected for radioactivity and weight measurements. Results : Human plasma clots incubated with F13 showed 280–740% greater counts per minute (CPM) than controls (p<0.01). F13 binding was dose-dependent and >90% inhibited by pretreatment with iodoacetamide, an alkylating agent. The blood half-life of F13 was calculated to be 16 minutes. In one hour thrombi, in vivo SPECT/CT imaging revealed strong focal F13 SPECT signal in the co-registered ipsilateral venous thrombi but not the contralateral normal jugular vein. One hour thrombi in the F13 group had 15-fold greater radioactivity than the C13 group (4.6±3.6% vs. 0.3±0.2% injected dose per gram tissue, IDGT, p<0.01). Compared to 1 hour thrombi, 16 hour old thrombi had 4-fold less F13 radioactivity (1.1%±0.1% IDGT, p<0.05). Conclusions : Blood transglutaminase FXIIIa can be noninvasively detected using a FXIIIa-sensitive and specific imaging agent for integrated SPECT/CT. The current in vivo results further validate that activated factor XIII is a hallmark of acute thrombi and declines in activity over time. This clinically translatable imaging strategy could permit visualization of FXIIIa in patients with thrombotic syndromes.

scholarly journals In vivo imaging and tracking of exosomes for theranostics

2021 ◽  
pp. 2130005
Author(s):  
Ning Ma ◽  
Changfeng Wu ◽  
Zihui Meng
Keyword(s):  
Clinical Application ◽  
In Vivo Imaging ◽  
Photoacoustic Imaging ◽  
Imaging Techniques ◽  
Cell Communication ◽  
Nuclear Imaging ◽  
Future Research ◽  
Uptake Mechanism ◽  
Lipid Bilayer Vesicles

Exosomes are lipid bilayer vesicles released by cells and serve as natural carriers for cell–cell communication. Exosomes provide a promising approach to the diagnosis and treatment of diseases and are considered as an alternative to cell therapy. However, one main restriction in their clinical application is that the current understanding of these vesicles, especially their in vivo behaviors and distributions, remains inadequate. Here, we reviewed the current and emerging methods for in vivo imaging and tracking of exosomes, including fluorescence imaging, bioluminescence imaging, nuclear imaging, X-ray imaging, magnetic resonance imaging, photoacoustic imaging, and multimodal imaging. In vivo imaging and tracking of exosomes by these methods can help researchers further understand their uptake mechanism, biodistribution, migration, function, and therapeutic performance. The pioneering studies in this field can elucidate many unknown exosomal behaviors at different levels. We discussed the advantages and limitations of each labeling and imaging strategy. The advances in labeling and in vivo imaging will expand our understanding of exosomes and promote their clinical application. We finally provide a perspective and discuss several important issues that need to be explored in future research. This review highlights the values of efficient, sensitive, and biocompatible exosome labeling and imaging techniques in disease theranostics.

scholarly journals Perfluorocarbon Nanoparticles: Evolution of a Multimodality and Multifunctional Imaging Agent

Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Patrick M. Winter
Keyword(s):  
Drug Delivery ◽  
Molecular Imaging ◽  
Particle Surface ◽  
Nuclear Imaging ◽  
High Sensitivity ◽  
The Body ◽  
Low Levels ◽  
Potential Impact ◽  
High Payload

Perfluorocarbon nanoparticles offer a biologically inert, highly stable, and nontoxic platform that can be specifically designed to accomplish a range of molecular imaging and drug delivery functions in vivo. The particle surface can be decorated with targeting ligands to direct the agent to a variety of biomarkers that are associated with diseases such as cancer, cardiovascular disease, obesity, and thrombosis. The surface can also carry a high payload of imaging agents, ranging from paramagnetic metals for MRI, radionuclides for nuclear imaging, iodine for CT, and florescent tags for histology, allowing high sensitivity mapping of cellular receptors that may be expressed at very low levels in the body. In addition to these diagnostic imaging applications, the particles can be engineered to carry highly potent drugs and specifically deposit them into cell populations that display biosignatures of a variety of diseases. The highly flexible and robust nature of this combined molecular imaging and drug delivery vehicle has been exploited in a variety of animal models to demonstrate its potential impact on the care and treatment of patients suffering from some of the most debilitating diseases.

scholarly journals Ultrasonic Ring Array-Based Transient Triplet Differential Photoacoustic Imaging for Strong Background Removal

2021 ◽  
Vol 8 ◽  
Author(s):  
Guan Wang ◽  
Bo Wang ◽  
Tong Ye ◽  
Congcong Wang ◽  
Lili Guo ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Spatial Resolution ◽  
Photoacoustic Imaging ◽  
High Specificity ◽  
Background Signal ◽  
Background Removal ◽  
Differential Imaging

Photoacoustic imaging (PAI) is a fast evolving imaging technology enabling in vivo imaging with high specificity and spatial resolution. However, due to strong background signals from various intrinsic chromospheres such as melanin, photoacoustic imaging of targeting objects labeled by contrast agents remain a challenge. The transient triplet differential (TTD) method has shown a significant potential for background-free photoacoustic imaging. Here, we develop a photoacoustic system using an ultrasonic semicircular ring array for transient triplet differential imaging. Pt(II) Octaethylporphine (PtOEP) and black ink are used as the contrast agent and the phantom of melanoma, respectively. Using the TTD method, we could remove the strong background signal from black ink. The ratio between contrast agent signal and background signal is increased to about 10 times the previous one. Our finding demonstrates the potential of the TTD method on molecular imaging for strong background removal.

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