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Nature Nanotechnology May 2024Positron emission particle tracking (PEPT) enables 3D localization and tracking of single positron-emitting radiolabelled particles with high spatiotemporal resolution....
Positron emission particle tracking (PEPT) enables 3D localization and tracking of single positron-emitting radiolabelled particles with high spatiotemporal resolution. The translation of PEPT to the biomedical imaging field has been limited due to the lack of methods to radiolabel biocompatible particles with sufficient specific activity and protocols to isolate a single particle in the sub-micrometre size range, below the threshold for capillary embolization. Here we report two key developments: the synthesis and Ga-radiolabelling of homogeneous silica particles of 950 nm diameter with unprecedented specific activities (2.1 ± 1.4 kBq per particle), and the isolation and manipulation of a single particle. We have combined these developments to perform in vivo PEPT and dynamic positron emission tomography (PET) imaging of a single radiolabelled sub-micrometre size particle using a pre-clinical positron emission tomography/computed tomography scanner. This work opens possibilities for quantitative assessment of haemodynamics in vivo in real time, at the whole-body level using minimal amounts of injected radioactive dose and material.
Topics: Animals; Positron-Emission Tomography; Gallium Radioisotopes; Mice; Silicon Dioxide; Particle Size; Nanoparticles; Positron Emission Tomography Computed Tomography
PubMed: 38242986
DOI: 10.1038/s41565-023-01589-8 -
The Journal of Infectious Diseases Oct 2023Invasive fungal infections have become a major challenge for public health, mainly due to the growing numbers of immunocompromised patients, with high morbidity and... (Review)
Review
Invasive fungal infections have become a major challenge for public health, mainly due to the growing numbers of immunocompromised patients, with high morbidity and mortality. Currently, conventional imaging modalities such as computed tomography and magnetic resonance imaging contribute largely to the noninvasive diagnosis and treatment evaluation of those infections. These techniques, however, often fall short when a fast, noninvasive and specific diagnosis of fungal infection is necessary. Molecular imaging, especially using nuclear medicine-based techniques, aims to develop fungal-specific radiotracers that can be tested in preclinical models and eventually translated to human applications. In the last few decades, multiple radioligands have been developed and tested as potential fungal-specific tracers. These include radiolabeled peptides, antifungal drugs, siderophores, fungal-specific antibodies, and sugars. In this review, we provide an overview of the pros and cons of the available radiotracers. We also address the future prospects of fungal-specific imaging.
Topics: Humans; Positron-Emission Tomography; Mycoses; Antifungal Agents; Tomography, X-Ray Computed; Invasive Fungal Infections; Antibodies, Fungal
PubMed: 37788500
DOI: 10.1093/infdis/jiad067 -
Revista Da Associacao Medica Brasileira... 2023Fluorodeoxyglucose is not a tumor-specific agent and it can also be involved in benign conditions, which may cause diagnostic confusion. This research aims to elucidate...
OBJECTIVE
Fluorodeoxyglucose is not a tumor-specific agent and it can also be involved in benign conditions, which may cause diagnostic confusion. This research aims to elucidate the colonoscopic findings of patients who underwent colonoscopy due to colon involvement in positron emission tomography/computerized tomography.
METHODS
A total of 71 patients who underwent colonoscopy due to colonic involvement in positron emission tomography/computerized tomography at SBU Keçiören Training and Research Hospital Gastroenterology Clinic Endoscopy Unit have been analyzed retrospectively. Demographic characteristics of the patients, areas of involvement in positron emission tomography/computerized tomography, and severity have been obtained from the hospital database.
RESULTS
The gastrointestinal involvement area of 22.5% (n=16) of the patients was ascending colon, 15.5% (n=11) was sigmoid, 15.5% (n=11) was rectum, 12.7% (n=9) was stomach, 11.3% (n=8) was transverse colon, 8.5% (n=6) was anal canal, 5.6% (n=4) was esophagus, and 5.6% (n=4) was descending colon. The endoscopic findings of 19.7% (n=14) patients were normal, whereas 29.6% (n=21) had polyps, 9.9% (n=7) had cancer, 2.8% (n=2) had an ulcer, 15.5% (n=11) had gastritis, 14.1% (n=10) had hemorrhoids, and 7% (n=5) had colitis.
CONCLUSION
Fluorodeoxyglucose-positron emission tomography can detect unexpected distant metastases with high sensitivity because it allows whole-body imaging. Curative resection significantly contributes to the choice of treatment modality in the pre-operative period of colorectal cancer patients with planned surgery.
Topics: Humans; Retrospective Studies; Colon; Colonoscopy; Positron-Emission Tomography; Fluorodeoxyglucose F18; Colorectal Neoplasms; Positron Emission Tomography Computed Tomography
PubMed: 37792869
DOI: 10.1590/1806-9282.20230409 -
Molecules (Basel, Switzerland) Aug 2023Esterases are hydrolases that catalyze the hydrolysis of esters into the corresponding acids and alcohols. The development of fluorescent probes for detecting esterases... (Review)
Review
Esterases are hydrolases that catalyze the hydrolysis of esters into the corresponding acids and alcohols. The development of fluorescent probes for detecting esterases is of great importance due to their wide spectrum of biological and industrial applications. These probes can provide a rapid and sensitive method for detecting the presence and activity of esterases in various samples, including biological fluids, food products, and environmental samples. Fluorescent probes can also be used for monitoring the effects of drugs and environmental toxins on esterase activity, as well as to study the functions and mechanisms of these enzymes in several biological systems. Additionally, fluorescent probes can be designed to selectively target specific types of esterases, such as those found in pathogenic bacteria or cancer cells. In this review, we summarize the recent fluorescent probes described for the visualization of cell viability and some applications for in vivo imaging. On the other hand, positron emission tomography (PET) is a nuclear-based molecular imaging modality of great value for studying the activity of enzymes in vivo. We provide some examples of PET probes for imaging acetylcholinesterases and butyrylcholinesterases in the brain, which are valuable tools for diagnosing dementia and monitoring the effects of anticholinergic drugs on the central nervous system.
Topics: Esterases; Fluorescent Dyes; Positron-Emission Tomography; Hydrolases; Butyrylcholinesterase
PubMed: 37687094
DOI: 10.3390/molecules28176265 -
Biosensors Feb 2024Cancers of unknown primary (CUP) exhibit significant cellular heterogeneity and malignancy, which poses significant challenges for diagnosis and treatment. Recent years... (Review)
Review
Cancers of unknown primary (CUP) exhibit significant cellular heterogeneity and malignancy, which poses significant challenges for diagnosis and treatment. Recent years have seen deeper insights into the imaging, pathology, and genetic characteristics of CUP, driven by interdisciplinary collaboration and the evolution of diagnostic and therapeutic strategies. However, due to their insidious onset, lack of evidence-based medicine, and limited clinical understanding, diagnosing and treating CUP remain a significant challenge. To inspire more creative and fantastic research, herein, we report and highlight recent advances in the diagnosis and therapeutic strategies of CUP. Specifically, we discuss advanced diagnostic technologies, including 12-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography (18F-FDG PET/CT) or Ga-FAPI (fibroblast activation protein inhibitor) PET/CT, liquid biopsy, molecular diagnostics, self-assembling nanotechnology, and artificial intelligence (AI). In particular, the discussion will extend to the effective treatment techniques currently available, such as targeted therapies, immunotherapies, and bio-nanotechnology-based therapeutics. Finally, a novel perspective on the challenges and directions for future CUP diagnostic and therapeutic strategies is discussed.
Topics: Humans; Positron Emission Tomography Computed Tomography; Artificial Intelligence; Positron-Emission Tomography; Tomography, X-Ray Computed; Neoplasms, Unknown Primary; Fluorine Radioisotopes
PubMed: 38392019
DOI: 10.3390/bios14020100 -
EBioMedicine Nov 2023Progressive supranuclear palsy (PSP) is a primary 4-repeat tauopathy with diverse clinical phenotypes. Previous post-mortem studies examined tau deposition sequences in...
BACKGROUND
Progressive supranuclear palsy (PSP) is a primary 4-repeat tauopathy with diverse clinical phenotypes. Previous post-mortem studies examined tau deposition sequences in PSP, but in vivo scrutiny is lacking.
METHODS
We conducted [F]Florzolotau tau positron emission tomography (PET) scans on 148 patients who were clinically diagnosed with PSP and 20 healthy controls. We employed the Subtype and Stage Inference (SuStaIn) algorithm to identify PSP subtype/stage and related tau patterns, comparing clinical features across subtypes and assessing PSP stage-clinical severity association. We also evaluated functional connectivity differences among subtypes through resting-state functional magnetic resonance imaging.
FINDINGS
We identified two distinct subtypes of PSP: Subtype1 and Subtype2. Subtype1 typically exhibits a sequential progression of the disease, starting from subcortical and gradually moving to cortical regions. Conversely, Subtype2 is characterized by an early, simultaneous onset in both regions. Interestingly, once the disease is initiated, Subtype1 tends to spread more rapidly within each region compared to Subtype2. Individuals categorized as Subtype2 are generally older and exhibit less severe dysfunctions in areas such as cognition, bulbar, limb motor, and general motor functions compared to those with Subtype1. Moreover, they have a more favorable prognosis in terms of limb motor function. We found significant correlations between several clinical variables and the identified PSP SuStaIn stages. Furthermore, Subtype2 displayed a remarkable reduction in functional connectivity compared to Subtype1.
INTERPRETATION
We present the evidence of distinct in vivo spatiotemporal tau trajectories in PSP. Our findings can contribute to precision medicine advancements for PSP.
FUNDING
This work was supported by grants from the National Natural Science Foundation of China (number 82272039, 81971641, 82021002, and 92249302); Swiss National Science Foundation (number 188350); the STI2030-Major Project of China (number 2022ZD0211600); the Clinical Research Plan of Shanghai Hospital Development Center of China (number SHDC2020CR1038B); and the National Key R&D Program of China (number 2022YFC2009902, 2022YFC2009900), the China Scholarship Council (number 202006100181); the Deutsche Forschungsgemeinschaft (DFG) under Germany's Excellence Strategy within the framework of the Munich Cluster for Systems Neurology (EXC 2145 SyNergy, ID 390857198).
Topics: Humans; Supranuclear Palsy, Progressive; tau Proteins; China; Positron-Emission Tomography
PubMed: 37839135
DOI: 10.1016/j.ebiom.2023.104835 -
Neuroscience and Biobehavioral Reviews Apr 2024Conflicting evidence exists on the relationship between diabetes mellitus (DM) and Alzheimer's disease (AD) biomarkers. Therefore, we conducted a random-effects... (Meta-Analysis)
Meta-Analysis
Conflicting evidence exists on the relationship between diabetes mellitus (DM) and Alzheimer's disease (AD) biomarkers. Therefore, we conducted a random-effects meta-analysis to evaluate the correlation of glucose metabolism measures (glycated hemoglobin, fasting blood glucose, insulin resistance indices) and DM status with AD biomarkers of amyloid-β and tau measured by positron emission tomography or cerebrospinal fluid. We selected 37 studies from PubMed and Embase, including 11,694 individuals. More impaired glucose metabolism and DM status were associated with higher tau biomarkers (r=0.11[0.03-0.18], p=0.008; I2=68%), but were not associated with amyloid-β biomarkers (r=-0.06[-0.13-0.01], p=0.08; I=81%). Meta-regression revealed that glucose metabolism and DM were specifically associated with tau biomarkers in population settings (p=0.001). Furthermore, more impaired glucose metabolism and DM status were associated with lower amyloid-β biomarkers in memory clinic settings (p=0.004), and in studies with a higher prevalence of dementia (p<0.001) or lower cognitive scores (p=0.04). These findings indicate that DM is associated with biomarkers of tau but not with amyloid-β. This knowledge is valuable for improving dementia and DM diagnostics and treatment.
Topics: Humans; Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Cognitive Dysfunction; Diabetes Mellitus; Glucose; Peptide Fragments; Positron-Emission Tomography; tau Proteins
PubMed: 38423195
DOI: 10.1016/j.neubiorev.2024.105604 -
Journal of Digital Imaging Aug 2023Carimas is a multi-purpose medical imaging data processing tool, which can be used to visualize, analyze, and model different medical images in research. Originally, it...
Carimas is a multi-purpose medical imaging data processing tool, which can be used to visualize, analyze, and model different medical images in research. Originally, it was developed only for positron emission tomography data in 2009, but the use of this software has extended to many other tomography imaging modalities, such as computed tomography and magnetic resonance imaging. Carimas is especially well-suited for analysis of three- and four-dimensional image data and creating polar maps in modeling of cardiac perfusion. This article explores various parts of Carimas, including its key features, program structure, and application possibilities.
Topics: Humans; Positron-Emission Tomography; Tomography, X-Ray Computed; Heart; Magnetic Resonance Imaging; Software; Image Processing, Computer-Assisted
PubMed: 37106213
DOI: 10.1007/s10278-023-00812-1 -
The Quarterly Journal of Nuclear... Dec 2023The use of F sodium fluoride (F-NaF) in positron emission tomography (PET/CT) is increasing. This resurgence of an old tracer has been driven by several factors,...
The use of F sodium fluoride (F-NaF) in positron emission tomography (PET/CT) is increasing. This resurgence of an old tracer has been driven by several factors, including its superior diagnostic performance over standard 99mTc-based bone scintigraphy (BS), availability of PET/CT imaging systems, a shortened examination time and an increase in the number of regional commercial PET radiotracer distribution. In this special article, we aimed to highlight the current place of the F-NaF PET/CT in the imaging of bone metastases (BM) in a variety of malignancies. A special focus is given to the following ones: breast cancer (BC), prostate cancer (PCa). Also, other malignancies such as bladder cancer, lung cancer, thyroid cancer, multiple myeloma, head and neck cancer, hepatocellular carcinoma have been addressed. At last, we summarize the advantages and limits of the F-NaF PET/CT compared to other imaging modalities in these settings.
Topics: Male; Humans; Positron Emission Tomography Computed Tomography; Fluorine Radioisotopes; Bone Neoplasms; Positron-Emission Tomography; Sodium Fluoride; Prostatic Neoplasms
PubMed: 37750848
DOI: 10.23736/S1824-4785.23.03534-3 -
Cancer Radiotherapie : Journal de La... Sep 2023Over the last decades, the refinement of radiation therapy techniques has been associated with an increasing interest for individualized radiation therapy with the aim... (Review)
Review
Over the last decades, the refinement of radiation therapy techniques has been associated with an increasing interest for individualized radiation therapy with the aim of increasing or maintaining tumor control and reducing radiation toxicity. Developments in artificial intelligence (AI), particularly machine learning and deep learning, in imaging sciences, including nuclear medecine, have led to significant enthusiasm for the concept of "rapid learning health system". AI combined with radiomics applied to (F)-fluorodeoxyglucose positron emission tomography/computed tomography ([F]-FDG PET/CT) offers a unique opportunity for the development of predictive models that can help stratify each patient's risk and guide treatment decisions for optimal outcomes and quality of life of patients treated with radiation therapy. Here we present an overview of the current contribution of AI and radiomics-based machine learning models applied to (F)-FDG PET/CT in the management of cancer treated by radiation therapy.
Topics: Humans; Positron Emission Tomography Computed Tomography; Fluorodeoxyglucose F18; Artificial Intelligence; Quality of Life; Radiation Oncology
PubMed: 37481344
DOI: 10.1016/j.canrad.2023.06.001