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Study and Implementation of Convolutional Neural Network based Image Denoising
Published in Rajesh Singh, Anita Gehlot, P.S. Ranjit, Dolly Sharma, Futuristic Sustainable Energy and Technology, 2022
Eftakher Rasul, Mohammad Javed, Chintala Pullarao, Amandeep Singh
PET stands for positron emission tomography, and it’s a form of functional imaging that’s commonly used in clinical diagnosis. PET [17] is a functional imaging model that uses the injection of various radioactive tracers to observe molecular-level activities within tissues. A method is proposed for pretraining the network with simulation data and fine-tuning the networks with real data sets. PET [14] images have low image quality and signal-to-noise ratio (SNR) because of numerous physical decrease factors and a small number of observed photons. With a high SNR, the system improves image quality, balances texture and contrast, and improves image quality. The proposed technique produces images of higher quality than post-smoothing with a Gaussian or NLM filter, according to experimental findings.
Virus-Based Nanocarriers for Targeted Drug Delivery
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Semra Akgönüllü, Monireh Bakhshpour, Yeşeren Saylan, Adil Denizli
Virus-based nanocarriers have also been employed for other noninvasive imaging techniques, including PET (positron emission tomography). The principle of PET is based on the emission of radiation from a patient, radiopharmaceutical injected, is registered via external detectors positioned at several orientations (Omami et al. 2014). This technology frequently is used for longitudinal follow-up and cancer diagnosis. There are many platforms for use in the PET, such as mammalian viruses, bacteriophages, etc. (Shukla and Steinmetz 2015). For example; Farkas et al. modulated the nanoparticle-based agents, which are PEG chains addition. They labeled MS2 and MS2-PEG capsids that have DOTA chelators and injected them into mice that have tumour xenografts. As shown in Figure 9.7a, they used each MS2 coat protein monomer (amino phenylalanine (T19paF) and cysteine mutations) for facing exterior and interior surfaces. They attached maleimide-DOTA to the cysteines to let 64Cu binding for radio labeling (Figure 9.7b). They analysed disassembled proteins with an upper limit of conversion and attached PEG chains applying a fast reaction. They performed SDS-PAGE analysis in a short time to indicate 76% of the proteins (Figures 9.7c-e). They also compared with other capsids and observed that the MS2 agents depicted longer circulation times. Furthermore, the MS2 and MS2-PEG bacteriophages behaved the same, although the latter agent has remarkably less uptake in the spleen (Farkas et al. 2013).
Images from Radioactivity: Radionuclide Scans, SPECT, and PET
Published in Suzanne Amador Kane, Boris A. Gelman, Introduction to Physics in Modern Medicine, 2020
Suzanne Amador Kane, Boris A. Gelman
PET imaging works by using radioactive versions of common body chemicals to illuminate the workings of the brain. Radioactivity also plays a role in other low-cost, commonly used diagnostic techniques. These radionuclide imaging techniques give physicians an important tool for visualizing the functioning of many organs. For example, radionuclide “bone scans” can be used to detect inflammation due to arthritis, and radionuclide procedures for cardiology can measure the effectiveness with which the heart pumps blood. Specific radioactive chemical labels also can vividly highlight the presence of tumors (Figure 6.1).
Development of Tracer Particles for Positron Emission Particle Tracking
Published in Nuclear Science and Engineering, 2023
Thomas Leadbeater, Andy Buffler, Michael van Heerden, Ameerah Camroodien, Deon Steyn
Fluorine-18 has a 109.8-min half-life decaying by positron emission at 97% intensity with no associated gamma photon emissions.50 It forms very strong covalent bonds with carbon compounds and can be incorporated into a wide variety of organic molecules. The most widely used radiotracer in medical PET by far is 18FDG, having proven to be of great utility in the rate measurement of glycolytic metabolism.48 A different set of ion exchange reactions from those used for 68Ga enables different materials to be labeled with positron activity such that both the range of possible tracer particles and the useful lifetime are extended.
Nuclear Medicine in Oncology
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2018
Carla Oliveira, Rui Parafita, Ana Canudo, Joana Correia Castanheira, Durval C. Costa
PET is a tomographic imaging procedure that uses radiopharmaceuticals labelled with positron emitting isotopes. The emitted positrons, when combined with electrons, annihilate one another. The mass-energy conversion results in a pair of 511 keV gamma photons (two photons emitted simultaneously in opposite directions for each annihilation event) which are detected by the scanner. Presently, the majority of PET scanners feature a computerised tomography scanner component (CT) – hybrid equipment – to correct for photon attenuation and also for anatomical referencing of the lesions identified by the PET component.
Developments in the human machine interface technologies and their applications: a review
Published in Journal of Medical Engineering & Technology, 2021
Harpreet Pal Singh, Parlad Kumar
Few other types of metabolic neuroimaging techniques are also available for medical diagnosis by accessing the biosignals like functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and functional near infra-red spectroscopy (fNIR) [133]. Functional magnetic resonance imaging is a type of MRI scanning technique that determines the hemodynamic response by detecting the changes in blood flow, thereby able to measure the brain metabolic activity. It is further used for the diagnostics and treatment of various brain disorders and other kinds of diseases that cannot be detected by any other MRI technique [134]. PET is a radiology procedure used to examine the body tissues at specific conditions. The major area of application in which PET is currently being used is neurology, cardiology and oncology. In the PET examination procedure, very little radioactive substance called radionuclide is injected into the patient’s blood that emits the positrons and subsequently emerged gamma rays are monitored using specialised apparatus [32,135]. In the fNIR technique, infra-red light is induced into the brain and subsequent changes of reflected light are examined to detect changes in various wavelengths. Based on scattering and absorption attributes, the shape of function maps of brain activities is developed [136]. But fNIR does not find extensive use by researchers because of its low temporal resolutions [137]. Near infra-red spectroscopy (NIRS) is used in critical care to monitor the oxygenation of the regional brain tissues [138]. Single-photon emission computed tomography (SPECT) is a nuclear tomographic imaging technique that follows the procedure of injecting a radioactive substance into the bloodstream of the patient and a specially designed gamma camera creates 3D images of the internal organs or the tissues to be examined [139].