scholarly journals High-Resolution Episcopic Microscopy (HREM) in Multimodal Imaging Approaches

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1918
Author(s):  
Katharina S. Keuenhof ◽  
Anoop Kavirayani ◽  
Susanne Reier ◽  
Stefan H. Geyer ◽  
Wolfgang J. Weninger ◽  
...  
Keyword(s):  
High Resolution ◽  
Multimodal Imaging ◽  
Ex Vivo ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Limited Area ◽  
Chemical Information ◽  
Volume Data

High-resolution episcopic microscopy (HREM) is a three-dimensional (3D) episcopic imaging modality based on the acquisition of two-dimensional (2D) images from the cut surface of a block of tissue embedded in resin. Such images, acquired serially through the entire length/depth of the tissue block, are aligned and stacked for 3D reconstruction. HREM has proven to be specifically advantageous when integrated in correlative multimodal imaging (CMI) pipelines. CMI creates a composite and zoomable view of exactly the same specimen and region of interest by (sequentially) correlating two or more modalities. CMI combines complementary modalities to gain holistic structural, functional, and chemical information of the entire sample and place molecular details into their overall spatiotemporal multiscale context. HREM has an advantage over in vivo 3D imaging techniques on account of better histomorphologic resolution while simultaneously providing volume data. HREM also has certain advantages over ex vivo light microscopy modalities. The latter can provide better cellular resolution but usually covers a limited area or volume of tissue, with limited 3D structural context. HREM has predominantly filled a niche in the phenotyping of embryos and characterisation of anatomic developmental abnormalities in various species. Under the umbrella of CMI, when combined with histopathology in a mutually complementary manner, HREM could find wider application in additional nonclinical and translational areas. HREM, being a modified histology technique, could also be incorporated into specialised preclinical pathology workflows. This review will highlight HREM as a versatile imaging platform in CMI approaches and present its benefits and limitations.

High-resolution in vivo imaging of peripheral nerves using optical coherence tomography: a feasibility study

2020 ◽  
Vol 132 (6) ◽  
pp. 1907-1913 ◽  
Author(s):  
Anne E. Carolus ◽  
Marcel Lenz ◽  
Martin Hofmann ◽  
Hubert Welp ◽  
Kirsten Schmieder ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Peripheral Nerves ◽  
Imaging Technique ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Optical Biopsy ◽  
Optical Coherence

OBJECTIVEBecause of their complex topography, long courses, and small diameters, peripheral nerves are challenging structures for radiological diagnostics. However, imaging techniques in the area of peripheral nerve diseases have undergone unexpected development in recent decades. They include MRI and high-resolution sonography (HRS). Yet none of those imaging techniques reaches a resolution comparable to that of histological sections. Fascicles are the smallest discernable structure. Optical coherence tomography (OCT) is the first imaging technique that is able to depict a nerve’s ultrastructure at micrometer resolution. In the current study, the authors present an in vivo assessment of human peripheral nerves using OCT.METHODSOCT measurement was performed in 34 patients with different peripheral nerve pathologies, i.e., nerve compression syndromes. The nerves were examined during surgery after their exposure. Only the sural nerve was twice examined ex vivo. The Thorlabs OCT systems Callisto and Ganymede were used. For intraoperative use, a hand probe was covered with a sterile foil. Different postprocessing imaging techniques were applied and evaluated. In order to highlight certain structures, five texture parameters based on gray-level co-occurrence matrices were calculated according to Haralick.RESULTSThe intraoperative use of OCT is easy and intuitive. Image artifacts are mainly caused by motion and the sterile foil. If the artifacts are kept at a low level, the hyporeflecting bundles of nerve fascicles and their inner parts can be displayed. In the Haralick evaluation, the second angular moment is most suitable to depict the connective tissue.CONCLUSIONSOCT is a new imaging technique that has shown promise in peripheral nerve surgery for particular questions. Its resolution exceeds that provided by recent radiological possibilities such as MRI and HRS. Since its field of view is relatively small, faster acquisition times would be highly desirable and have already been demonstrated by other groups. Currently, the method resembles an optical biopsy and can be a supplement to intraoperative sonography, giving high-resolution insight into a suspect area that has been located by sonography in advance.

scholarly journals In-Vivo and Ex-Vivo Tissue Analysis through Hyperspectral Imaging Techniques: Revealing the Invisible Features of Cancer

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 756 ◽  
Author(s):  
Martin Halicek ◽  
Himar Fabelo ◽  
Samuel Ortega ◽  
Gustavo M. Callico ◽  
Baowei Fei
Keyword(s):  
Hyperspectral Imaging ◽  
Cancer Detection ◽  
Ex Vivo ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Spectral Signature ◽  
Electromagnetic Spectrum ◽  
Label Free ◽  
Imaging Tool

In contrast to conventional optical imaging modalities, hyperspectral imaging (HSI) is able to capture much more information from a certain scene, both within and beyond the visual spectral range (from 400 to 700 nm). This imaging modality is based on the principle that each material provides different responses to light reflection, absorption, and scattering across the electromagnetic spectrum. Due to these properties, it is possible to differentiate and identify the different materials/substances presented in a certain scene by their spectral signature. Over the last two decades, HSI has demonstrated potential to become a powerful tool to study and identify several diseases in the medical field, being a non-contact, non-ionizing, and a label-free imaging modality. In this review, the use of HSI as an imaging tool for the analysis and detection of cancer is presented. The basic concepts related to this technology are detailed. The most relevant, state-of-the-art studies that can be found in the literature using HSI for cancer analysis are presented and summarized, both in-vivo and ex-vivo. Lastly, we discuss the current limitations of this technology in the field of cancer detection, together with some insights into possible future steps in the improvement of this technology.

scholarly journals New artery of knowledge: 3D models of angiogenesis

2019 ◽  
Vol 1 (1) ◽  
pp. H135-H143
Author(s):  
Eleonora Zucchelli ◽  
Qasim A Majid ◽  
Gabor Foldes
Keyword(s):  
Network Formation ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
3D Models ◽  
Complex Processes ◽  
Organ Repair ◽  
Three Dimensional Models

Angiogenesis and vasculogenesis are complex processes by which new blood vessels are formed and expanded. They play a pivotal role not only in physiological development and growth and tissue and organ repair, but also in a range of pathological conditions, from tumour formation to chronic inflammation and atherosclerosis. Understanding the multistep cell-differentiation programmes and identifying the key molecular players of physiological angiogenesis/vasculogenesis are critical to tackle pathological mechanisms. While many questions are yet to be answered, increasingly sophisticated in vitro, in vivo and ex vivo models of angiogenesis/vasculogenesis, together with cutting-edge imaging techniques, allowed for recent major advances in the field. This review aims to summarise the three-dimensional models available to study vascular network formation and to discuss advantages and limitations of the current systems.

scholarly journals In Vivo Imaging of Biodegradable Implants and Related Tissue Biomarkers

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2348
Author(s):  
Leon Riehakainen ◽  
Chiara Cavallini ◽  
Paolo Armanetti ◽  
Daniele Panetta ◽  
Davide Caramella ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Imaging Techniques ◽  
Special Focus ◽  
Tissue Remodelling ◽  
Biodegradable Implant ◽  
Advantages And Disadvantages ◽  
Non Invasive ◽  
Positron Emission ◽  
Longitudinal Imaging

Non-invasive longitudinal imaging of osseointegration of bone implants is essential to ensure a comprehensive, physical and biochemical understanding of the processes related to a successful implant integration and its long-term clinical outcome. This study critically reviews the present imaging techniques that may play a role to assess the initial stability, bone quality and quantity, associated tissue remodelling dependent on implanted material, implantation site (surrounding tissues and placement depth), and biomarkers that may be targeted. An updated list of biodegradable implant materials that have been reported in the literature, from metal, polymer and ceramic categories, is provided with reference to the use of specific imaging modalities (computed tomography, positron emission tomography, ultrasound, photoacoustic and magnetic resonance imaging) suitable for longitudinal and non-invasive imaging in humans. The advantages and disadvantages of the single imaging modality are discussed with a special focus on preclinical imaging for biodegradable implant research. Indeed, the investigation of a new implant commonly requires histological examination, which is invasive and does not allow longitudinal studies, thus requiring a large number of animals for preclinical testing. For this reason, an update of the multimodal and multi-parametric imaging capabilities will be here presented with a specific focus on modern biomaterial research.

scholarly journals In VivoVisualization of Heterogeneous Intratumoral Distribution of Hypoxia-Inducible Factor-1αActivity by the Fusion of High-Resolution SPECT and Morphological Imaging Tests

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Hirofumi Fujii ◽  
Masayuki Yamaguchi ◽  
Kazumasa Inoue ◽  
Yasuko Mutou ◽  
Masashi Ueda ◽  
...  
Keyword(s):  
High Resolution ◽  
Ex Vivo ◽  
Hypoxia Inducible Factor ◽  
Chimeric Protein ◽  
Small Animal ◽  
Ct Scanner ◽  
Heterogeneous Distribution ◽  
Fusion Images ◽  
Intratumoral Distribution

Purpose. We aimed to clearly visualize heterogeneous distribution of hypoxia-inducible factor 1α(HIF) activity in tumor tissuesin vivo.Methods. We synthesized of125I-IPOS, a125I labeled chimeric protein probe, that would visualize HIF activity. The biodistribution of125I-IPOS in FM3A tumor-bearing mice was evaluated. Then, the intratumoral localization of this probe was observed by autoradiography, and it was compared with histopathological findings. The distribution of125I-IPOS in tumors was imaged by a small animal SPECT/CT scanner. The obtainedin vivoSPECT-CT fusion images were compared withex vivoimages of excised tumors. Fusion imaging with MRI was also examined.Results.125I-IPOS well accumulated in FM3A tumors. The intratumoral distribution of125I-IPOS by autoradiography was quite heterogeneous, and it partially overlapped with that of pimonidazole. High-resolution SPECT-CT fusion images successfully demonstrated the heterogeneity of125I-IPOS distribution inside tumors. SPECT-MRI fusion images could give more detailed information about the intratumoral distribution of125I-IPOS.Conclusion. High-resolution SPECT images successfully demonstrated heterogeneous intratumoral distribution of125I-IPOS. SPECT-CT fusion images, more favorably SPECT-MRI fusion images, would be useful to understand the features of heterogeneous intratumoral expression of HIF activityin vivo.

High-Resolution Magnetic Resonance Imaging of the Human Median Nerve

2004 ◽  
Vol 18 (2) ◽  
pp. 80-87 ◽  
Author(s):  
Archie Heddings ◽  
Mehmet Bilgen ◽  
Randolph Nudo ◽  
Bruce Toby ◽  
Terence McIff ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Peripheral Nerve ◽  
Median Nerve ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Proton Density ◽  
Resonance Imaging ◽  
Imaging Protocols

Objectives. It is widely accepted that peripheral nerve repairs performed within 6 weeks of injury have much better outcomes than those performed at later dates. However, there is no diagnostic technique that can determine if a traumatic peripheral nerve injury requires surgical intervention in the early postinjury phase. The objective of this article was to determine whether novel, noninvasive magnetic resonance imaging techniques could demonstrate the microstructure of human peripheral nerves that is necessary for determining prognosis and determining if surgery is indicated following traumatic injury. Methods. Ex vivo magnetic resonance imaging protocols were developed on a 9.4-T research scanner using spin-echo proton density and gradient-echo imaging sequences and a specially designed, inductively coupled radio frequency coil. These imaging protocols were applied to in situ imaging of the human median nerve in 4 fresh-frozen cadaver arms. Results. Noninvasive high-resolution images of the human median nerve were obtained. Structures in the nerve that were observed included fascicles, interfascicular epineurium, perineurium, and intrafascicular septations. Conclusion. Application of these imaging techniques to clinical scanners could provide physicians with a tool that is capable of grading the severity of nerve injuries and providing indications for surgery in the early postinjury phase.

scholarly journals Tracking Transplanted Stem Cells Using Magnetic Resonance Imaging and the Nanoparticle Labeling Method in Urology

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jae Heon Kim ◽  
Hong J. Lee ◽  
Yun Seob Song
Keyword(s):  
Magnetic Resonance Imaging ◽  
Stem Cells ◽  
Molecular Imaging ◽  
Magnetic Resonance ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Imaging Method ◽  
Resonance Imaging

A reliablein vivoimaging method to localize transplanted cells and monitor their viability would enable a systematic investigation of cell therapy. Most stem cell transplantation studies have used immunohistological staining, which does not provide information about the migration of transplanted cellsin vivoin the same host. Molecular imaging visualizes targeted cells in a living host, which enables determining the biological processes occurring in transplanted stem cells. Molecular imaging with labeled nanoparticles provides the opportunity to monitor transplanted cells noninvasively without sacrifice and to repeatedly evaluate them. Among several molecular imaging techniques, magnetic resonance imaging (MRI) provides high resolution and sensitivity of transplanted cells. MRI is a powerful noninvasive imaging modality with excellent image resolution for studying cellular dynamics. Several types of nanoparticles including superparamagnetic iron oxide nanoparticles and magnetic nanoparticles have been used to magnetically label stem cells and monitor viability by MRI in the urologic field. This review focuses on the current role and limitations of MRI with labeled nanoparticles for tracking transplanted stem cells in urology.

scholarly journals Imaging and Molecular Mechanisms of Alzheimer’s Disease: A Review

2018 ◽  
Vol 19 (12) ◽  
pp. 3702 ◽  
Author(s):  
Grazia Femminella ◽  
Tony Thayanandan ◽  
Valeria Calsolaro ◽  
Klara Komici ◽  
Giuseppe Rengo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Multimodal Imaging ◽  
Molecular Mechanisms ◽  
Imaging Techniques ◽  
Structural Mri ◽  
Imaging Biomarkers ◽  
Significant Burden ◽  
Made In

Alzheimer’s disease is the most common form of dementia and is a significant burden for affected patients, carers, and health systems. Great advances have been made in understanding its pathophysiology, to a point that we are moving from a purely clinical diagnosis to a biological one based on the use of biomarkers. Among those, imaging biomarkers are invaluable in Alzheimer’s, as they provide an in vivo window to the pathological processes occurring in Alzheimer’s brain. While some imaging techniques are still under evaluation in the research setting, some have reached widespread clinical use. In this review, we provide an overview of the most commonly used imaging biomarkers in Alzheimer’s disease, from molecular PET imaging to structural MRI, emphasising the concept that multimodal imaging would likely prove to be the optimal tool in the future of Alzheimer’s research and clinical practice.

scholarly journals In Vivo Imaging of Peripheral Benzodiazepine Receptors in Mouse Lungs: A Biomarker of Inflammation

2005 ◽  
Vol 4 (4) ◽  
pp. 7290.2005.05133 ◽  
Author(s):  
Matthew J. Hardwick ◽  
Ming-Kai Chen ◽  
Kwamena Baidoo ◽  
Martin G. Pomper ◽  
Tomás R. Guilarte
Keyword(s):  
In Vivo Imaging ◽  
Ex Vivo ◽  
Inflammatory Diseases ◽  
Imaging Techniques ◽  
Benzodiazepine Receptors ◽  
Small Animal ◽  
Small Animal Pet ◽  
Planar Imaging ◽  
Peripheral Benzodiazepine Receptors

The ability to visualize the immune response with radioligands targeted to immune cells will enhance our understanding of cellular responses in inflammatory diseases. Peripheral benzodiazepine receptors (PBR) are present in monocytes and neutrophils as well as in lung tissue. We used lipopolysaccharide (LPS) as a model of inflammation to assess whether the PBR could be used as a noninvasive marker of inflammation in the lungs. Planar imaging of mice administrated 10 or 30 mg/kg LPS showed increased [123I]-( R)-PK11195 radioactivity in the thorax 2 days after LPS treatment relative to control. Following imaging, lungs from control and LPS-treated mice were harvested for ex vivo gamma counting and showed significantly increased radioactivity above control levels. The specificity of the PBR response was determined using a blocking dose of nonradioactive PK11195 given 30 min prior to radiotracer injection. Static planar images of the thorax of nonradioactive PK11195 pretreated animals showed a significantly lower level of radiotracer accumulation in control and in LPS-treated animals ( p < .05). These data show that LPS induces specific increases in PBR ligand binding in the lungs. We also used in vivo small-animal PET studies to demonstrate increased [11C]-( R)-PK11195 accumulation in the lungs of LPS-treated mice. This study suggests that measuring PBR expression using in vivo imaging techniques may be a useful biomarker to image lung inflammation.

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