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Scientific Reports Dec 2019Quantitative assessment of functional perfusion capacity and vessel architecture is critical when validating biomaterials for regenerative medicine purposes and requires...
Quantitative assessment of functional perfusion capacity and vessel architecture is critical when validating biomaterials for regenerative medicine purposes and requires high-tech analytical methods. Here, combining two clinically relevant imaging techniques, (magnetic resonance imaging; MRI and microcomputed tomography; MicroCT) and using the chorioallantoic membrane (CAM) assay, we present and validate a novel functional and morphological three-dimensional (3D) analysis strategy to study neovascularization in biomaterials relevant for bone regeneration. Using our new pump-assisted approach, the two scaffolds, Optimaix (laminar structure mimicking entities of the diaphysis) and DegraPol (highly porous resembling spongy bone), were shown to directly affect the architecture of the ingrowing neovasculature. Perfusion capacity (MRI) and total vessel volume (MicroCT) strongly correlated for both biomaterials, suggesting that our approach allows for a comprehensive evaluation of the vascularization pattern and efficiency of biomaterials. Being compliant with the 3R-principles (replacement, reduction and refinement), the well-established and easy-to-handle CAM model offers many advantages such as low costs, immune-incompetence and short experimental times with high-grade read-outs when compared to conventional animal models. Therefore, combined with our imaging-guided approach it represents a powerful tool to study angiogenesis in biomaterials.
Topics: Animals; Biocompatible Materials; Bone Regeneration; Chick Embryo; Diaphyses; Imaging, Three-Dimensional; Magnetic Resonance Imaging; Materials Testing; Multimodal Imaging; Neovascularization, Physiologic; Porosity; Regenerative Medicine; Tissue Scaffolds; X-Ray Microtomography
PubMed: 31857617
DOI: 10.1038/s41598-019-55411-4 -
Magyar Onkologia Sep 2013Hungary is first in head and neck cancer mortality in Europe in men and also in women. Head and neck (HN) is a difficult region, its anatomy and also pathology is very... (Review)
Review
Hungary is first in head and neck cancer mortality in Europe in men and also in women. Head and neck (HN) is a difficult region, its anatomy and also pathology is very complex, various connection points exist between the sites which determine the extension of the disease. Diagnostic algorithms as well as imaging techniques have to be optimized to examine in standard manner. Like most other cancers, prognosis depends largely on the stage of the tumor. Accuracy of tumor detection and evaluation is very important because it affects treatment planning. As non-surgical organ-preserving therapeutic modalities (chemotherapy, chemoradiotherapy, targeted biological therapy) gain general acceptance, the importance of noninvasive diagnostic accuracy as well as radiologic evaluation of the extent of the tumor has increased. Clinical examinations including endoscopy should be combined with radiologic imaging to assess the precise local (T), regional nodal (N), and distant (M) extent of the tumor. Computed tomography (CT) and magnetic resonance imaging (MRI) have become basic tools in the diagnosis of head and neck tumors. They are both useful for assessing deep tumor extensions, able to detect changes missed by endoscopy. It has been shown that the primary determined tumor stage increases in up to 90% of patients after the results of cross sectional imaging. MRI is being increasingly used and has become the gold standard in head and neck cancer for staging, assessing tumor response, finding recurrent tumor and also for treatment planning in radiotherapy. The field strength of MRI scanners has been increasing to 1.5 T and now 3 T with better signal-to-noise ratio, higher resolution images and better tissue diagnosis. Functional MR techniques such as dynamic contrast enhanced MRI (DCE-MRI) and diffusion weighted MRI (DW-MRI) may provide further characterization. PET/CT is beneficial in detecting unsuspected metastatic nodes, distant disease and second primary tumor. PET/CT and MRI both appeared almost similarly accurate in the detection of an occult primary tumor. The effective management of patients depends highly on the competece of radiologists and requires close collaboration between clinical and surgical oncologists, diagnostic and therapeutic radiologists as well as pathologists.
Topics: Carcinoma, Squamous Cell; Diffusion Magnetic Resonance Imaging; Female; Head and Neck Neoplasms; Humans; Hungary; Magnetic Resonance Imaging; Male; Multimodal Imaging; Positron-Emission Tomography; Tomography, X-Ray Computed
PubMed: 24107825
DOI: No ID Found -
Contrast Media & Molecular Imaging 2017Surgical resection remains the most promising treatment strategy for many types of cancer. Residual malignant tissue after surgery, a consequence in part due to positive...
Surgical resection remains the most promising treatment strategy for many types of cancer. Residual malignant tissue after surgery, a consequence in part due to positive margins, contributes to high mortality and disease recurrence. In this study, multimodal contrast agents for integrated preoperative magnetic resonance imaging (MRI) and intraoperative fluorescence image-guided surgery (FIGS) are developed. Self-assembled multimodal imaging nanoparticles (SAMINs) were developed as a mixed micelle formulation using amphiphilic HA polymers functionalized with either GdDTPA for contrast-enhanced MRI or Cy7.5, a near infrared fluorophore. To evaluate the relationship between MR and fluorescence signal from SAMINs, we employed simulated surgical phantoms that are routinely used to evaluate the depth at which near infrared (NIR) imaging agents can be detected by FIGS. Finally, imaging agent efficacy was evaluated in a human breast tumor xenograft model in nude mice, which demonstrated contrast in both fluorescence and magnetic resonance imaging.
Topics: Animals; Breast Neoplasms; Female; Heterografts; Humans; Hyaluronic Acid; Intraoperative Period; Magnetic Resonance Imaging; Mice; Multimodal Imaging; Nanoparticles; Optical Imaging; Phantoms, Imaging; Preoperative Period; Surgery, Computer-Assisted
PubMed: 29097944
DOI: 10.1155/2017/9616791 -
International Journal of Nanomedicine 2014While nanoparticles are usually designed for targeted drug delivery, they can also simultaneously provide diagnostic information by a variety of in vivo imaging methods.... (Review)
Review
While nanoparticles are usually designed for targeted drug delivery, they can also simultaneously provide diagnostic information by a variety of in vivo imaging methods. These diagnostic capabilities make use of specific properties of nanoparticle core materials. Near-infrared fluorescent probes provide optical detection of cells targeted by real-time nanoparticle-distribution studies within the organ compartments of live, anesthetized animals. By combining different imaging modalities, we can start with deep-body imaging by magnetic resonance imaging or computed tomography, and by using optical imaging, get down to the resolution required for real-time fluorescence-guided surgery.
Topics: Animals; Contrast Media; Humans; Image Enhancement; Multimodal Imaging; Nanomedicine; Nanoparticles; Surgery, Computer-Assisted
PubMed: 24511229
DOI: 10.2147/IJN.S53717 -
Small (Weinheim An Der Bergstrasse,... Sep 2015Advances in biomedical imaging have spurred the development of integrated multimodal scanners, usually capable of two simultaneous imaging modes. The long-term vision of... (Review)
Review
Advances in biomedical imaging have spurred the development of integrated multimodal scanners, usually capable of two simultaneous imaging modes. The long-term vision of higher-order multimodality is to improve diagnostics or guidance through the analysis of complementary, data-rich, co-registered images. Synergies achieved through combined modalities could enable researchers to better track diverse physiological and structural events, analyze biodistribution and treatment efficacy, and compare established and emerging modalities. Higher-order multimodal approaches stand to benefit from molecular imaging probes and, in recent years, contrast agents that have hypermodal characteristics have increasingly been reported in preclinical studies. Given the chemical requirements for contrast agents representing various modalities to be integrated into a single entity, the higher-order multimodal agents reported so far tend to be of nanoparticulate form. To date, the majority of reported nanoparticles have included components that are active for magnetic resonance. Herein, recent progress in higher-order multimodal imaging agents is reviewed, spanning a range of material and structural classes, and demonstrating utility in three (or more) imaging modalities.
Topics: Contrast Media; Diagnostic Imaging; Humans; Multimodal Imaging
PubMed: 26185099
DOI: 10.1002/smll.201500735 -
Journal of Nuclear Medicine : Official... Apr 2013Spatial and temporal coregistration of nuclear and optical images can enable the fusion of the information from these complementary molecular imaging modalities. A...
UNLABELLED
Spatial and temporal coregistration of nuclear and optical images can enable the fusion of the information from these complementary molecular imaging modalities. A critical challenge is in integrating the optical and nuclear imaging hardware. Flexible fiber-based fluorescence-mediated tomography (FMT) systems provide a viable solution. The various bore sizes of small-animal nuclear imaging systems can potentially accommodate the FMT fiber imaging arrays. In addition, FMT imaging facilitates coregistration of the nuclear and optical contrasts in time. Herein, we combine a fiber-based FMT system with a preclinical SPECT/CT platform. Feasibility of in vivo imaging is demonstrated by tracking a monomolecular multimodal imaging agent (MOMIA) during transport from the forepaw to the axillary lymph node region of a rat.
METHODS
The fiber-based, video-rate FMT imaging system is composed of 12 sources (785- and 830-nm laser diodes) and 13 detectors. To maintain high temporal sampling, the system simultaneously acquires ratio-metric data at each detector. A 3-dimensional finite element model derived from CT projections provides anatomically based light propagation modeling. Injection of a MOMIA intradermally into the forepaw of rats provided spatially and temporally coregistered nuclear and optical contrasts. FMT data were acquired concurrently with SPECT and CT data. The incorporation of SPECT data as a priori information in the reconstruction of FMT data integrated both optical and nuclear contrasts.
RESULTS
Accurate depth localization of phantoms with different thicknesses was accomplished with an average center-of-mass error of 4.1 ± 2.1 mm between FMT and SPECT measurements. During in vivo tests, fluorescence and radioactivity from the MOMIA were colocalized in spatially coincident regions with an average center-of-mass error of 2.68 ± 1.0 mm between FMT and SPECT for axillary lymph node localization. Intravital imaging with surgical exposure of the lymph node validated the localization of the optical contrast.
CONCLUSION
The feasibility of integrating a fiber-based, video-rate FMT system with a commercial preclinical SPECT/CT platform was established. These coregistered FMT and SPECT/CT results with MOMIAs may facilitate the development of the next generation of preclinical and clinical multimodal optical-nuclear platforms for a broad array of imaging applications and help elucidate the underlying biologic processes relevant to cancer diagnosis and therapy monitoring.
Topics: Animals; Feasibility Studies; Female; Image Processing, Computer-Assisted; Multimodal Imaging; Positron-Emission Tomography; Rats; Rats, Sprague-Dawley; Spectrometry, Fluorescence; Tomography, Optical; Tomography, X-Ray Computed
PubMed: 23447655
DOI: 10.2967/jnumed.112.105742 -
Survey of Ophthalmology 2023An array of retinochoroid imaging modalities aid in comprehensive evaluation of the immunopathological changes in the retina and choroid, forming the core component for... (Review)
Review
An array of retinochoroid imaging modalities aid in comprehensive evaluation of the immunopathological changes in the retina and choroid, forming the core component for the diagnosis and management of inflammatory disorders such as uveitis. The recent technological breakthroughs have led to the development of imaging platforms that can evaluate the layers of retina and choroid and the structural and functional alteration in these tissues. Ophthalmologists heavily rely on imaging modalities such as dye-based angiographies (fluorescein angiography and indocyanine green angiography), optical coherence tomography, fundus autofluorescence, as well as dye-less angiography such as optical coherence tomography angiograph,y for establishing a precise diagnosis and understanding the pathophysiology of the diseases. Furthermore, these tools are now being deployed with a 'multimodal' approach for swift and accurate diagnosis. In this comprehensive review, we outline the imaging platforms used for evaluation of posterior uveitis and discuss the organized, algorithmic approach for the assessment of the disorders. Additionally, we provide an insight into disease-specific characteristic pathological changes and the established strategies to rule out disorders with overlapping features on imaging.
Topics: Humans; Multimodal Imaging; Uveitis, Posterior; Uveitis; Fluorescein Angiography; Fundus Oculi; Tomography, Optical Coherence; Choroid
PubMed: 36724831
DOI: 10.1016/j.survophthal.2023.01.006 -
Scientific Reports Apr 2021The ability to characterize the combined structural, functional, and thermal properties of biophysically dynamic samples is needed to address critical questions related...
The ability to characterize the combined structural, functional, and thermal properties of biophysically dynamic samples is needed to address critical questions related to tissue structure, physiological dynamics, and disease progression. Towards this, we have developed an imaging platform that enables multiple nonlinear imaging modalities to be combined with thermal imaging on a common sample. Here we demonstrate label-free multimodal imaging of live cells, excised tissues, and live rodent brain models. While potential applications of this technology are wide-ranging, we expect it to be especially useful in addressing biomedical research questions aimed at the biomolecular and biophysical properties of tissue and their physiology.
Topics: Humans; Multimodal Imaging; Optical Imaging
PubMed: 33850171
DOI: 10.1038/s41598-021-86774-2 -
Science Advances Jun 2017Bidirectional interfacing with the nervous system enables neuroscience research, diagnosis, and therapy. This two-way communication allows us to monitor the state of the... (Review)
Review
Bidirectional interfacing with the nervous system enables neuroscience research, diagnosis, and therapy. This two-way communication allows us to monitor the state of the brain and its composite networks and cells as well as to influence them to treat disease or repair/restore sensory or motor function. To provide the most stable and effective interface, the tools of the trade must bridge the soft, ion-rich, and evolving nature of neural tissue with the largely rigid, static realm of microelectronics and medical instruments that allow for readout, analysis, and/or control. In this Review, we describe how the understanding of neural signaling and material-tissue interactions has fueled the expansion of the available tool set. New probe architectures and materials, nanoparticles, dyes, and designer genetically encoded proteins push the limits of recording and stimulation lifetime, localization, and specificity, blurring the boundary between living tissue and engineered tools. Understanding these approaches, their modality, and the role of cross-disciplinary development will support new neurotherapies and prostheses and provide neuroscientists and neurologists with unprecedented access to the brain.
Topics: Animals; Biosensing Techniques; Brain; Electrophysiological Phenomena; Humans; Molecular Imaging; Molecular Probe Techniques; Multimodal Imaging; Nervous System Physiological Phenomena; Neurons; Physical Stimulation
PubMed: 28630894
DOI: 10.1126/sciadv.1601649 -
International Journal of Molecular... Dec 2014Photoacoustic imaging (PAI) and thermoacoustic imaging (TAI) are two emerging biomedical imaging techniques that both utilize ultrasonic signals as an information... (Review)
Review
Photoacoustic imaging (PAI) and thermoacoustic imaging (TAI) are two emerging biomedical imaging techniques that both utilize ultrasonic signals as an information carrier. Unique advantages of PAI and TAI are their abilities to provide high resolution functional information such as hemoglobin and blood oxygenation and tissue dielectric properties relevant to physiology and pathology. These two methods, however, may have a limited detection depth and lack of endogenous contrast. An exogenous contrast agent is often needed to effectively resolve these problems. Such agents are able to greatly enhance the imaging contrast and potentially break through the imaging depth limit. Furthermore, a receptor-targeted contrast agent could trace the molecular and cellular biological processes in tissues. Thus, photoacoustic and thermoacoustic molecular imaging can be outstanding tools for early diagnosis, precise lesion localization, and molecular typing of various diseases. The agents also could be used for therapy in conjugation with drugs or in photothermal therapy, where it functions as an enhancer for the integration of diagnosis and therapy. In this article, we present a detailed review about various exogenous contrast agents for photoacoustic and thermoacoustic molecular imaging. In addition, challenges and future directions of photoacoustic and thermoacoustic molecular imaging in the field of translational medicine are also discussed.
Topics: Animals; Contrast Media; Humans; Multimodal Imaging; Neoplasms; Photoacoustic Techniques; Tomography, Optical
PubMed: 25530615
DOI: 10.3390/ijms151223616