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Current Protocols in Cytometry Mar 2020In light microscopy, illuminating light is passed through the sample as uniformly as possible over the field of view. For thicker samples, where the objective lens does...
In light microscopy, illuminating light is passed through the sample as uniformly as possible over the field of view. For thicker samples, where the objective lens does not have sufficient depth of focus, light from sample planes above and below the focal plane will also be detected. The out-of-focus light will add blur to the image, reducing the resolution. In fluorescence microscopy, any dye molecules in the field of view will be stimulated, including those in out-of-focus planes. Confocal microscopy provides a means of rejecting the out-of-focus light from the detector such that it does not contribute blur to the images being collected. This technique allows for high-resolution imaging in thick tissues. In a confocal microscope, the illumination and detection optics are focused on the same diffraction-limited spot in the sample, which is the only spot imaged by the detector during a confocal scan. To generate a complete image, the spot must be moved over the sample and data collected point by point. A significant advantage of the confocal microscope is the optical sectioning provided, which allows for 3D reconstruction of a sample from high-resolution stacks of images. Several types of confocal microscopes have been developed for this purpose, and each has different advantages and disadvantages. This article provides a concise introduction to confocal microscopy. © 2019 by John Wiley & Sons, Inc.
Topics: Animals; Drosophila; HeLa Cells; Humans; Larva; Microscopy, Confocal; Microtubules; Sample Size; Time Factors
PubMed: 31876974
DOI: 10.1002/cpcy.68 -
View (Beijing, China) Jun 2021The coronaviruses have caused severe acute respiratory syndrome (SARS), the Middle East respiratory syndrome (MERS), and the more recent coronavirus pneumonia... (Review)
Review
The coronaviruses have caused severe acute respiratory syndrome (SARS), the Middle East respiratory syndrome (MERS), and the more recent coronavirus pneumonia (COVID-19). The global COVID-19 pandemic requires urgent action to develop anti-virals, new therapeutics, and vaccines. In this review, we discuss potential therapeutics including human recombinant ACE2 soluble, inflammatory cytokine inhibitors, and direct anti-viral agents such as remdesivir and favipiravir, to limit their fatality. We also discuss the structure of the SARS-CoV-2, which is crucial to the timely development of therapeutics, and previous attempts to generate vaccines against SARS-CoV and MERS-CoV. Finally, we provide an overview of the role of nanotechnology in the development of therapeutics as well as in the diagnosis of the infection. This information is key for computational modeling and nanomedicine-based new therapeutics by counteracting the variable proteins in the virus. Further, we also try to effectively share the latest information about many different aspects of COVID-19 vaccine developments and possible management to further scientific endeavors.
PubMed: 34766165
DOI: 10.1002/VIW.20200155 -
Frontiers in Cardiovascular Medicine 2021Echocardiography is widely used because of its portability, high temporal resolution, absence of radiation, and due to the low-costs. Over the past years,... (Review)
Review
Echocardiography is widely used because of its portability, high temporal resolution, absence of radiation, and due to the low-costs. Over the past years, echocardiography has been recommended by the European Society of Cardiology in most cardiac diseases for both diagnostic and prognostic purposes. These recommendations have led to an increase in number of performed studies each requiring diligent processing and reviewing. The standard work pattern of image analysis including quantification and reporting has become highly resource intensive and time consuming. Existence of a large number of datasets with digital echocardiography images and recent advent of AI technology have created an environment in which artificial intelligence (AI) solutions can be developed successfully to automate current manual workflow. We report on published AI solutions for echocardiography analysis on methods' performance, characteristics of the used data and imaged population. Contemporary AI applications are available for automation and advent in the image acquisition, analysis, reporting and education. AI solutions have been developed for both diagnostic and predictive tasks in echocardiography. Left ventricular function assessment and quantification have been most often performed. Performance of automated image view classification, image quality enhancement, cardiac function assessment, disease classification, and cardiac event prediction was overall good but most studies lack external evaluation. Contemporary AI solutions for image acquisition, analysis, reporting and education are developed for relevant tasks with promising performance. In the future major benefit of AI in echocardiography is expected from improvements in automated analysis and interpretation to reduce workload and improve clinical outcome. Some of the challenges have yet to be overcome, however, none of them are insurmountable.
PubMed: 33708808
DOI: 10.3389/fcvm.2021.648877 -
Eye and Vision (London, England) 2018The Retinal Function Imager (RFI) provides in vivo and noninvasive imaging of both the retinal structure and function. (Review)
Review
BACKGROUND
The Retinal Function Imager (RFI) provides in vivo and noninvasive imaging of both the retinal structure and function.
REVIEW
The RFI can create capillary perfusion maps, measure blood flow velocity, and determine metabolic function including blood oximetry. It can aid clinical diagnosis as well as assess treatment response in several retinal vascular diseases including diabetic retinopathy. Blood flow velocity abnormalities have also been implicated in disease such as age-related macular degeneration and require further investigation. Compared with optical coherence tomography angiography, the RFI produces capillary maps of comparable image quality and wider field of view but it is unable to provide depth-resolved information and has longer image acquisition time. Currently, functional imaging using blood oximetry has limited applications and additional research is required.
CONCLUSION
The RFI offers noninvasive, high-resolution imaging of retinal microvasculature by creating capillary perfusion maps. In addition, it is capable of measuring retinal blood velocity directly and performs functional imaging with retinal blood oximetry. Its clinical applications are broad and additional research with functional imaging may potentially lead to diagnosis of diseases and their progression before anatomic abnormalities become evident, but longer image acquisition times may limit its clinical adoption.
PubMed: 30123814
DOI: 10.1186/s40662-018-0114-1 -
Frontiers in Neuroinformatics 2022Biomedical image registration refers to aligning corresponding anatomical structures among different images, which is critical to many tasks, such as brain atlas... (Review)
Review
Biomedical image registration refers to aligning corresponding anatomical structures among different images, which is critical to many tasks, such as brain atlas building, tumor growth monitoring, and image fusion-based medical diagnosis. However, high-throughput biomedical image registration remains challenging due to inherent variations in the intensity, texture, and anatomy resulting from different imaging modalities, different sample preparation methods, or different developmental stages of the imaged subject. Recently, Generative Adversarial Networks (GAN) have attracted increasing interest in both mono- and cross-modal biomedical image registrations due to their special ability to eliminate the modal variance and their adversarial training strategy. This paper provides a comprehensive survey of the GAN-based mono- and cross-modal biomedical image registration methods. According to the different implementation strategies, we organize the GAN-based mono- and cross-modal biomedical image registration methods into four categories: modality translation, symmetric learning, adversarial strategies, and joint training. The key concepts, the main contributions, and the advantages and disadvantages of the different strategies are summarized and discussed. Finally, we analyze the statistics of all the cited works from different points of view and reveal future trends for GAN-based biomedical image registration studies.
PubMed: 36483313
DOI: 10.3389/fninf.2022.933230 -
Journal of Medical Radiation Sciences Mar 2022To report for the first time the image quality of mammograms performed in Papua New Guinea (PNG) using the Perfect, Good, Moderate, Inadequate (PGMI) image evaluation... (Review)
Review
INTRODUCTION
To report for the first time the image quality of mammograms performed in Papua New Guinea (PNG) using the Perfect, Good, Moderate, Inadequate (PGMI) image evaluation system (IES); and to benchmark the image quality against BreastScreen Australia (BSA) National Accreditation Standards (NAS).
METHODS
A retrospective image quality analysis of the de-identified mammograms of 102 women imaged at the Port Moresby General Hospital (PMGH) was undertaken using the PGMI IES. Each craniocaudal (CC) and mediolateral oblique (MLO) image was assigned a grade and the reasons for the grade recorded. Age was recorded in years. Simple frequency analysis was undertaken and comparison with BSA NAS 2.4 was made.
RESULTS
Women were aged between 25 and 74 years. There were 111 CC views and 109 MLO views. The most frequent individual grade for the CC view was G (83.8%) and for the MLO view M (72.48%); and for a routine series (four images), P and G combined (14.8%). Non-visualisation of the IMA (28%), nipple not in profile (26%) and short length of pectoral muscle (12%) were the most cited reasons for assigning an M grade.
CONCLUSION
The reported image quality is not commensurate with that required by BSA (P and G > 50%) and while common positioning errors can be rectified through education and training, it is also important to recognise the complex challenges faced by PNG radiographers in obtaining mammographic images that extend beyond education and training and reflect the emerging nature of the modality as well as wider health, economic and other issues. This work raises the need for national standards, dedicated equipment, and radiographer education to best serve the women of PNG.
Topics: Adult; Aged; Australia; Breast Neoplasms; Female; Humans; Mammography; Middle Aged; Papua New Guinea; Pectoralis Muscles; Retrospective Studies
PubMed: 34418330
DOI: 10.1002/jmrs.538 -
PET Clinics Jan 2021New protocols for imaging cancer have been developed to take advantage of the improved imaging capabilities of long axial field-of-view PET scanners. Both research and... (Review)
Review
New protocols for imaging cancer have been developed to take advantage of the improved imaging capabilities of long axial field-of-view PET scanners. Both research and clinical applications have been pursued with encouraging early results. Clinical studies have demonstrated improved image quality and the ability to image with less injected activity or for shorter duration. With the increased sensitivity inherent in total-body PET scanners and new imaging paradigms, new challenges in image interpretation have emerged. New research applications have also emerged, including dosimetry, cell tracking, and dual-tracer applications.
Topics: Humans; Medical Oncology; Neoplasms; Positron Emission Tomography Computed Tomography; Reproducibility of Results; Whole Body Imaging
PubMed: 33218605
DOI: 10.1016/j.cpet.2020.09.010 -
View (Beijing, China) Jul 2022Since the outbreak of COVID-19, the number of confirmed cases and deaths has increased globally at a dramatic speed. In view of the serious health threat to humans, this... (Review)
Review
Since the outbreak of COVID-19, the number of confirmed cases and deaths has increased globally at a dramatic speed. In view of the serious health threat to humans, this review discusses the state-of-the-art studies about fighting this disease. It summarizes the current strategies and recent advances in detecting, preventing, and treating COVID-19 and interprets the underlying mechanisms in detail. Detection of COVID-19 can be successfully achieved by multiple techniques such as polymerase chain reaction, computed tomography imaging, and nano-biosensing. Inactivated virus vaccine, nucleic acid vaccine, and different nanoparticles have been employed to effectively prevent COVID-19. A variety of agents such as antiviral agents, neutralizing antibodies, and nanotherapeutics have been developed to treat COVID-19 with exciting efficacy. Although nanobiotechnology has shown great potential in the diagnosis, prevention, and treatment of COVID-19, efforts should be made to explore new biocompatible nano-biomaterials to advance this field to clinical applications. Hence, nanobiotechnology paves a new way to detect, prevent, and treat COVID-19 effectively.
PubMed: 35600668
DOI: 10.1002/VIW.20200181 -
Journal of Biomedical Optics Aug 2022Photoacoustic tomography (PAT) is a widely explored imaging modality and has excellent potential for clinical applications. On the acoustic detection side, limited-view...
SIGNIFICANCE
Photoacoustic tomography (PAT) is a widely explored imaging modality and has excellent potential for clinical applications. On the acoustic detection side, limited-view angle and limited-bandwidth are common key issues in PAT systems that result in unwanted artifacts. While analytical and simulation studies of limited-view artifacts are fairly extensive, experimental setups capable of comparing limited-view to an ideal full-view case are lacking.
AIMS
A custom ring-shaped detector array was assembled and mounted to a 6-axis robot, then rotated and translated to achieve up to 3.8π steradian view angle coverage of an imaged object.
APPROACH
Minimization of negativity artifacts and phantom imaging were used to optimize the system, followed by demonstrative imaging of a star contrast phantom, a synthetic breast tumor specimen phantom, and a vascular phantom.
RESULTS
Optimization of the angular/rotation scans found ≈212 effective detectors were needed for high-quality images, while 15-mm steps were used to increase the field of view as required depending on the size of the imaged object. Example phantoms were clearly imaged with all discerning features visible and minimal artifacts.
CONCLUSIONS
A near full-view closed spherical system has been developed, paving the way for future work demonstrating experimentally the significant advantages of using a full-view PAT setup.
Topics: Artifacts; Breast; Computer Simulation; Humans; Image Processing, Computer-Assisted; Phantoms, Imaging; Photoacoustic Techniques; Tomography; Tomography, X-Ray Computed
PubMed: 36042544
DOI: 10.1117/1.JBO.27.8.086004 -
Optics Express Jun 2020Poor access to eye care is a major global challenge that could be ameliorated by low-cost, portable, and easy-to-use diagnostic technologies. Diffuser-based imaging has...
Poor access to eye care is a major global challenge that could be ameliorated by low-cost, portable, and easy-to-use diagnostic technologies. Diffuser-based imaging has the potential to enable inexpensive, compact optical systems that can reconstruct a focused image of an object over a range of defocus errors. Here, we present a diffuser-based computational funduscope that reconstructs important clinical features of a model eye. Compared to existing diffuser-imager architectures, our system features an infinite-conjugate design by relaying the ocular lens onto the diffuser. This offers shift-invariance across a wide field-of-view (FOV) and an invariant magnification across an extended depth range. Experimentally, we demonstrate fundus image reconstruction over a 33 FOV and robustness to ±4D refractive error using a constant point-spread-function. Combined with diffuser-based wavefront sensing, this technology could enable combined ocular aberrometry and funduscopic screening through a single diffuser sensor.
Topics: Diagnostic Imaging; Equipment Design; Humans; Image Processing, Computer-Assisted; Light; Models, Theoretical; Ophthalmoscopes; Retina
PubMed: 32672237
DOI: 10.1364/OE.395112