Magnetic resonance imaging (MRI): A review of genetic damage investigations

Advances of surgical robotics: image-guided classification and application

Surgical robotics application in the field of minimally invasive surgery has developed rapidly and has been attracting increasingly more research attention in recent years. A common consensus has been reached that surgical procedures are to become less traumatic and with the implementation of more intelligence and higher autonomy, which is a serious challenge faced by the environmental sensing capabilities of robotic systems. One of the main sources of environmental information for robots are images, which are the basis of robot vision. In this review article, we divide clinical image into direct and indirect based on the object of information acquisition, and into continuous, intermittent continuous, and discontinuous according to the target-tracking frequency. The characteristics and applications of the existing surgical robots in each category are introduced based on these two dimensions. Our purpose in conducting this review was to analyze, summarize, and discuss the current evidence on the general rules on the application of image technologies for medical purposes. Our analysis gives insight and provides guidance conducive to the development of more advanced surgical robotics systems in the future.

Recent advances in the development of multiplexed nanophotonic biosensors

The field of nanophotonics has advanced and can be utilized as a method to detect different infectious diseases. The introduction of multiplex nanophotonic diagnostics has enabled the speedy and simultaneous detection of viral infections and specific biomarkers. The quick reaction times, high sensitivity, and specificity of multiplex nanophotonic diagnostics enable real-time identification of viruses without the need for nucleic acid amplification. This review presents an overview of nanophotonic tools used to identify diseases and particular biomarkers. The paper also examines possible research areas for the development of unique, cutting-edge multiplex nanophotonic diagnostics capable of concurrently detecting various diseases or biomarkers/biomolecules. Furthermore, it discusses barriers to further advancement and offers insight into anticipated trends.

Artificial Intelligence in Pancreatic Image Analysis: A Review

Pancreatic cancer is a highly lethal disease with a poor prognosis. Its early diagnosis and accurate treatment mainly rely on medical imaging, so accurate medical image analysis is especially vital for pancreatic cancer patients. However, medical image analysis of pancreatic cancer is facing challenges due to ambiguous symptoms, high misdiagnosis rates, and significant financial costs. Artificial intelligence (AI) offers a promising solution by relieving medical personnel's workload, improving clinical decision-making, and reducing patient costs. This study focuses on AI applications such as segmentation, classification, object detection, and prognosis prediction across five types of medical imaging: CT, MRI, EUS, PET, and pathological images, as well as integrating these imaging modalities to boost diagnostic accuracy and treatment efficiency. In addition, this study discusses current hot topics and future directions aimed at overcoming the challenges in AI-enabled automated pancreatic cancer diagnosis algorithms.

Emerging Applications of Picture Archiving and Communication Systems and Their Impact on Research and Education: A Literature Review

In recent times, technological advancements have remarkably improved picture archiving and communication system (PACS) capabilities beyond their conventional use in radiology departments. Researchers and instructors have started employing PACS functionalities to improve medical research processes, promote interdisciplinary collaborations, and facilitate learning. To illustrate this point further, the PACS enables researchers to handle and analyze huge amounts of imaging data with superior precision and speed, supporting innovative studies in areas like disease progression, treatment outcomes, and imaging modalities. Moreover, a PACS integrated with artificial intelligence (AI) algorithms leads to significant improvements in image processing, diagnostic accuracy, and personalized treatment, thus marking a new approach to medical imaging. The PACS supported by AI is mostly transformative since they allow for improved early disease detection capabilities as well as automated image processing and decision assistance, which increase diagnostic accuracy and clinical outcomes. Such systems can rapidly process large quantities of visual data with an accuracy rate surpassing earlier endeavors. In medical research, however, combining PACS with AI allows challenging imaging datasets to be examined, thereby making findings that were not previously possible. The capacity to combine imaging outcomes with clinical information is valuable for medical students and professionals in the field of education. They can access extensive medical image collections and case studies using PACS. This link is critical for teaching and learning as it allows students to interact with concrete events and improve their diagnostic accuracy in a controlled environment. This review discusses how the PACS affects educational courses and clinical outcomes based on the available literature. Our aim was not only to outline recent research or developments but also to present a comprehensive overview regarding the growing role played by PACS in the modern healthcare system and academics. Similarly, we look at the challenges and opportunities associated with the wide adoption of PACS, highlighting possible future areas of study or teaching methodologies. Issues such as data security, interoperability, and the need for defined protocols are included to give an exhaustive understanding of what PACS can and cannot do. Through this study, we stress PACS's revolutionary potential in advancing research methodology and educational practices, eventually contributing to enhanced patient care and knowledge dissemination in healthcare areas. The continual growth of PACS technology and its applications is expected to reshape the landscape of medical research and education, making it a vital component in the quest for medical excellence. By knowing the present trends and future potential, stakeholders in healthcare and education may better employ PACS to reach their objectives and boost overall results.

Super-resolution techniques for biomedical applications and challenges

Super-resolution (SR) techniques have revolutionized the field of biomedical applications by detailing the structures at resolutions beyond the limits of imaging or measuring tools. These techniques have been applied in various biomedical applications, including microscopy, magnetic resonance imaging (MRI), computed tomography (CT), X-ray, electroencephalogram (EEG), ultrasound, etc. SR methods are categorized into two main types: traditional non-learning-based methods and modern learning-based approaches. In both applications, SR methodologies have been effectively utilized on biomedical images, enhancing the visualization of complex biological structures. Additionally, these methods have been employed on biomedical data, leading to improvements in computational precision and efficiency for biomedical simulations. The use of SR techniques has resulted in more detailed and accurate analyses in diagnostics and research, essential for early disease detection and treatment planning. However, challenges such as computational demands, data interpretation complexities, and the lack of unified high-quality data persist. The article emphasizes these issues, underscoring the need for ongoing development in SR technologies to further improve biomedical research and patient care outcomes.

Sex differences in anhedonia in bipolar depression: a resting-state fMRI study

Previous studies about anhedonia symptoms in bipolar depression (BD) ignored the unique role of gender on brain function. This study aims to explore the regional brain neuroimaging features of BD with anhedonia and the sex differences in these patients. The resting-fMRI by applying fractional amplitude of low-frequency fluctuation (fALFF) method was estimated in 263 patients with BD (174 high anhedonia [HA], 89 low anhedonia [LA]) and 213 healthy controls. The effects of two different factors in patients with BD were analyzed using a 3 (group: HA, LA, HC) × 2 (sex: male, female) ANOVA. The fALFF values were higher in the HA group than in the LA group in the right medial cingulate gyrus and supplementary motor area. For the sex-by-group interaction, the fALFF values of the right hippocampus, left medial occipital gyrus, right insula, and bilateral medial cingulate gyrus were significantly higher in HA males than in LA males but not females. These results suggested that the pattern of high activation could be a marker of anhedonia symptoms in BD males, and the sex differences should be considered in future studies of BD with anhedonia symptoms.

Ultra-high static magnetic field induces a change in the spectrum but not frequency of DNA spontaneous mutations in Arabidopsis thaliana

Biological effects of magnetic fields have been extensively studied in plants, microorganisms and animals, and applications of magnetic fields in regulation of plant growth and phytoprotection is a promising field in sustainable agriculture. However, the effect of magnetic fields especially ultra-high static magnetic field (UHSMF) on genomic stability is largely unclear. Here, we investigated the mutagenicity of 24.5, 30.5 and 33.0 T UHSMFs with the gradient of 150, 95 and 0 T/m, respectively, via whole genome sequencing. Our results showed that 1 h exposure of Arabidopsis dried seeds to UHSMFs has no significant effect on the average rate of DNA mutations including single nucleotide variations and InDels (insertions and deletions) in comparison with the control, but 33.0 T and 24.5 T treatments lead to a significant change in the rate of nucleotide transitions and InDels longer than 3 bp, respectively, suggesting that both strength and gradient of UHSMF impact molecular spectrum of DNA mutations. We also found that the decreased transition rate in UHSMF groups is correlated with the upstream flanking sequences of G and C mutation sites. Furthermore, the germination rate of seeds exposed to 24.5 T SMF with -150 T/m gradient showed a significant decrease at 24 hours after sowing. Overall, our data lay a basis for precisely assessing the potential risk of UHSMF on DNA stability, and for elucidating molecular mechanism underlying gradient SMF-regulated biological processes in the future.

The sex differences in anhedonia in major depressive disorder: A resting-state fMRI study

OBJECTIVE

The external behavioural manifestations and internal neural mechanisms of anhedonia are sexually dimorphic. This study aimed to explore the sex differences in the regional brain neuroimaging features of anhedonia in the context of major depressive disorder (MDD).

METHOD

The resting-fMRI by applying amplitude of low-frequency fluctuation (ALFF) method was estimated in 414 patients with MDD (281 high anhedonia [HA], 133 low anhedonia [LA]) and 213 healthy controls (HC). The effects of two factors in patients with MDD were analysed using a 2 (sex: male, female) × 2 (group: HA, LA) ANOVA concerning the brain regions in which statistical differences were identified between patients with MDD and HC. We followed up with patients with HA at baseline, and 43 patients completed a second fMRI scan in remission. Paired t-test was performed to compare the ALFF values of anhedonia-related brain regions between the baseline and remission periods.

RESULTS

For the sex-by-group interaction, the bilateral insula, right hippocampus, right post cingulum cortex, and left putamen showed significant differences. Furthermore, the abnormally elevated ALFF values in anhedonia-related brain regions at baseline decreased in remission.

CONCLUSION

Our findings point to the fact that the females showed unique patterns of anhedonia-related brain activity compared to males, which may have clinical implications for interfering with the anhedonia symptoms in MDD. Using task fMRI, we can further examine the distinct characteristics between consumption anhedonia and anticipation anhedonia in MDD.

The relationship between disrupted anhedonia-related circuitry and suicidal ideation in major depressive disorder: A network-based analysis

BACKGROUND

Several epidemiological studies and psychological models have suggested that major depressive disorder (MDD) with anhedonia is associated with suicidal ideation (SI). However, little is known about whether the functional network pattern and intrinsic topologically disrupted in patients with anhedonia are related to SI.

METHODS

The resting-fMRI by applying network-based statistic (NBS) and graph-theory analyses was estimated in 273 patients with MDD (144 high anhedonia [HA], 129 low anhedonia [LA]) and 150 healthy controls. In addition, we quantified the SI scores of each patient. Finally, the mediation analysis assessed whether anhedonia symptoms could mediate the relationship between anhedonia-related network metrics and SI.

RESULT

The NBS analysis demonstrated that individuals with HA have a single abnormally increased functional connectivity component in a frontal-limbic circuit (termed the "anhedonia-related network", including the frontal cortex, striatum, anterior cingulate cortex and amygdala). The graph-theory analysis demonstrated that the anhedonia-related network showed a significantly disrupted topological organization (lower gamma and lambda), which the small-world property trend randomized. Furthermore, the anhedonia symptoms could mediate the relationship between the anhedonia-related network metrics (the mean functional connectivity values, the area under the curves values of gamma and nodal local efficiency in nucleus accumbens) and SI.

CONCLUSIONS

We found that disruption of the reward-related network in MDD leads to SI through anhedonia symptoms. These findings show the abnormal topological construction of functional brain network organization in anhedonia, shedding light on the neurological processes underlying SI in MDD patients with anhedonia symptoms.

Recent Research Progress of 19 F Magnetic Resonance Imaging Probes: Principle, Design, and Their Application

Visualization of biomolecules, cells, and tissues, as well as metabolic processes in vivo is significant for studying the associated biological activities. Fluorine magnetic resonance imaging (19 F MRI) holds potential among various imaging technologies thanks to its negligible background signal and deep tissue penetration in vivo. To achieve detection on the targets with high resolution and accuracy, requirements of high-performance 19 F MRI probes are demanding. An ideal 19 F MRI probe is thought to have, first, fluorine tags with magnetically equivalent 19 F nuclei, second, high fluorine content, third, adequate fluorine nuclei mobility, as well as excellent water solubility or dispersity, but not limited to. This review summarizes the research progresses of 19 F MRI probes and mainly discusses the impacts of structures on in vitro and in vivo imaging performances. Additionally, the applications of 19 F MRI probes in ions sensing, molecular structures analysis, cells tracking, and in vivo diagnosis of disease lesions are also covered in this article. From authors' perspectives, this review is able to provide inspirations for relevant researchers on designing and synthesizing advanced 19 F MRI probes.

Germany's journey toward 14 Tesla human magnetic resonance

Multiple sites within Germany operate human MRI systems with magnetic fields either at 7 Tesla or 9.4 Tesla. In 2013, these sites formed a network to facilitate and harmonize the research being conducted at the different sites and make this technology available to a larger community of researchers and clinicians not only within Germany, but also worldwide. The German Ultrahigh Field Imaging (GUFI) network has defined a strategic goal to establish a 14 Tesla whole-body human MRI system as a national research resource in Germany as the next progression in magnetic field strength. This paper summarizes the history of this initiative, the current status, the motivation for pursuing MR imaging and spectroscopy at such a high magnetic field strength, and the technical and funding challenges involved. It focuses on the scientific and science policy process from the perspective in Germany, and is not intended to be a comprehensive systematic review of the benefits and technical challenges of higher field strengths.

Imaging in Healthcare: A Glance at the Present and a Glimpse Into the Future

The utilization of artificial intelligence (AI) applications in medical imaging relies heavily on imaging informatics. That is a one-of-a-kind professional who works at the crossroads of clinical radiography, data science, and information technology. Imaging informaticians are becoming crucial players in expanding, assessing, and implementing AI in the medical setting. Teleradiology will continue to be a cost-effective healthcare facility that expands. Vendor neutral archive (VNA) isolates image presentation and storing systems, permitting platforms to develop quickly, and is a repository for organization-wide healthcare image data. Efforts are made to incorporate and integrate diagnostic facilities such as radiography and pathology to fulfill the needs and demands of targeted therapy. Developments in computer-aided medical object identification may alter the environment of patient services. Finally, interpreting and processing distinct complex healthcare data will create a data-rich context where evidence-based care and performance development may be driven.

Metal-organic frameworks: A promising option for the diagnosis and treatment of Alzheimer's disease

Beta-amyloid (Aβ) peptide is one of the main characteristic biomarkers of Alzheimer's disease (AD). Previous clinical investigations have proposed that unusual concentrations of this biomarker in cerebrospinal fluid, blood, and brain tissue are closely associated with the AD progression. Therefore, the critical point of early diagnosis, prevention, and treatment of AD is to monitor the levels of Aβ. In view of the potential of metal-organic frameworks (MOFs) for diagnosing and treating the AD, much attention has been focused in recent years. This review discusses the latest advances in the applications of MOFs for the early diagnosis of AD via fluorescence and electrochemiluminescence (ECL) detection of AD biomarkers, fluorescence detection of the main metal ions in the brain (Zn²⁺, Cu²⁺, Mn²⁺, Fe³⁺, and Al³⁺) in addition to magnetic resonance imaging (MRI) of the Aβ plaques. The current challenges and future strategies for translating the in vitro applications of MOFs into in vivo diagnosis of the AD are discussed.

Porphyrin NanoMetal-Organic Frameworks as Cancer Theranostic Agents

Metal-Organic Frameworks (MOFs) are hybrid multifunctional platforms that have found remarkable applications in cancer treatment and diagnostics. Independently, these materials can be employed in cancer treatment as intelligent drug carriers in chemotherapy, photothermal therapy, and photodynamic therapy; conversely, MOFs can further be used as diagnostic tools in fluorescence imaging, magnetic resonance imaging, computed tomography imaging, and photoacoustic imaging. One essential property of these materials is their great ability to fine-tune their composition toward a specific application by way of a judicious choice of the starting building materials (metal nodes and organic ligands). Moreover, many advancements were made concerning the preparation of these materials, including the ability to downsize the crystallites yielding nanoporous porphyrin MOFs (NMOFs) which are of great interest for clinical treatment and diagnostic theranostic tools. The usage of porphyrins as ligands allows a high degree of multifunctionality. Historically these molecules are well known for their reactive oxygen species formation and strong fluorescence characteristics, and both have proved helpful in cancer treatment and diagnostic tools. The anticipation that porphyrins in MOFs could prompt the resulting materials to multifunctional theranostic platforms is a reality nowadays with a series of remarkable and ground-breaking reports available in the literature. This is particularly remarkable in the last five years, when the scientific community witnessed rapid development in porphyrin MOFs theranostic agents through the development of imaging technologies and treatment strategies for cancer. This manuscript reviews the most relevant recent results and achievements in this particular area of interest in MOF chemistry and application.

White matter microstructure associated with anhedonia among individuals with bipolar disorders and high-risk for bipolar disorders

BACKGROUND

Anhedonia - a key symptom of depression - is highly associated with poorer outcomes and suicidal behavior. Alterations in the circuitry of reward-related brain regions have been robustly associated with anhedonia in unipolar depression, but not bipolar disorder (BD). We investigated white matter microstructures associated with anhedonia in participants with BD types I and II and first-degree relatives of patients with BD (BD-siblings).

METHODS

Eighty participants (BD types I and II: 56 [70%], and BD-siblings: 24 [30%]) underwent diffusion tensor imaging (DTI); Fractional anisotropy (FA) of different tracts were computed. Anhedonia was assessed using item 8, ("inability to feel'') of the MADRS scale. General linear models were used to compare the FA of different tracts in participants with and without anhedonia controlling for several clinical and demographic variables.

RESULTS

The mean age of the sample was 37 (± 11) years old, and 68.8% were female. Participants with anhedonia (32.5%) presented lower mean FA in the left uncinate fasciculus (UF) (p = 0.005), right temporal endings of the superior longitudinal fasciculus (SLFT) (p = 0.04), and in the left and right parietal endings of the superior longitudinal fasciculus (SLFP) (p = 0.003, and p = 0.04, respectively). Similar comparisons between participants with or without current depressive episodes and between participants with or without inner tension according to the MADRS did not show significant differences, specificity of the findings for anhedonia.

CONCLUSIONS

Lower FA in the left UF and SLF are potential neuroimaging markers of anhedonia in individuals with BD and high-risk for BD.

Detection and Classification of Knee Injuries from MR Images Using the MRNet Dataset with Progressively Operating Deep Learning Methods

This study aimed to build progressively operating deep learning models that could detect meniscus injuries, anterior cruciate ligament (ACL) tears and knee abnormalities in magnetic resonance imaging (MRI). The Stanford Machine Learning Group MRNet dataset was employed in the study, which included MRI image indexes in the coronal, sagittal, and axial axes, each having 1130 trains and 120 validation items. The study is divided into three sections. In the first section, suitable images are selected to determine the disease in the image index based on the disturbance under examination. It is also used to identify images that have been misclassified or are noisy and/or damaged to the degree that they cannot be utilised for diagnosis in the first section. The study employed the 50-layer residual networks (ResNet50) model in this section. The second part of the study involves locating the region to be focused on based on the disturbance that is targeted to be diagnosed in the image under examination. A novel model was built by integrating the convolutional neural networks (CNN) and the denoising autoencoder models in the second section. The third section is dedicated to making a diagnosis of the disease. In this section, a novel ResNet50 model is trained to identify disease diagnoses or abnormalities, independent of the ResNet50 model used in the first section. The images that each model selects as output after training are referred to as progressively operating deep learning methods since they are supplied as an input to the following model.

Clinical Applications of Biological Dosimetry in Patients Exposed to Low Dose Radiation Due to Radiological, Imaging or Nuclear Medicine Procedures

Radiation dosimetric biomarkers have found applications beyond radiation protection area and now are actively introduced into clinical practice. Cytogenetic assays appeared to be a valuable tool for individualized quantifying radiation effects in patients, with high capability for assessing genotoxicity of various medical exposure modalities and providing meaningful radiation dose estimates for prognoses of radiation-related cancer risk. This review summarized current data on the use of biological dosimetry methods in patients undergoing various medical irradiations to low doses. The highlighted topics include basic aspects of biological dosimetry and its limitations in the range of low radiation doses, and main patterns of in vivo induction of radiation biomarkers in clinical exposure scenarios, occurring in X-ray diagnostics, computed tomography, interventional radiology, low dose radiotherapy, and nuclear medicine (internally administered ¹³¹I and other radiopharmaceuticals). Additionally, several specific issues, examined by biodosimetry techniques, are analysed, such as contrast media effect, radiation response in pediatric patients, impact of magnetic resonance imaging, evaluation of radioprotectors, detection of patients' abnormal intrinsic radiosensitivity and dose estimation in persons involved in medical radiation incidents. A prognosis of possible directions for further improvements in this area includes the automation of cytogenetic analysis, introduction of molecular biodosimeters and development of multiparametric biodosimetry platforms. A potential approach to the advanced biodosimetry of internal exposure and/or low dose external irradiation is suggested; this can be a multiparametric platform based on the combination of the γ-H2AX foci, dicentric, and translocation assays, each applied in the optimum postexposure time range, with the amalgamation of the dose estimates. The study revealed the necessity of further research, which might clarify medical radiation safety concerns for patients via using stringent biodosimetry methodology.

Occupational exposure to electromagnetic fields in magnetic resonance environment: an update on regulation, exposure assessment techniques, health risk evaluation, and surveillance

Magnetic resonance imaging (MRI) is one of the most-used diagnostic imaging methods worldwide. There are ∼50,000 MRI scanners worldwide each of which involves a minimum of five workers from different disciplines who spend their working days around MRI scanners. This review analyzes the state of the art of literature about the several aspects of the occupational exposure to electromagnetic fields (EMF) in MRI: regulations, literature studies on biological effects, and health surveillance are addressed here in detail, along with a summary of the main approaches for exposure assessment. The original research papers published from 2013 to 2021 in international peer-reviewed journals, in the English language, are analyzed, together with documents published by legislative bodies. The key points for each topic are identified and described together with useful tips for precise safeguarding of MRI operators, in terms of exposure assessment, studies on biological effects, and health surveillance.

Brain magnetic resonance imaging without contrast significantly increased serum levels of IL-6, but not IL-10, IL-17A and TGF-β

Introduction: Magnetic Resonance Imaging (MRI) is a non-invasive imaging modality. However, the effects of MRI on the immune system in the in vivo conditions are yet to be clarified. In this study we explored the effects of routine brain MRI on the protein and mRNA peripheral blood levels of interleukin-6 (IL-6), IL-10, IL-17A and transforming growth factor-beta (TGF-β).Material and methods: 40 subjects, who referred for brain MRI, were entered for evaluating effects of routine brain MRI on the protein and mRNA peripheral blood levels of IL-6, IL-10, IL-17A and TGF-β. Accordingly, peripheral blood were collected before and 3 hours after MRI from the participants. Protein levels of the cytokines were evaluated using ELISA. Also, mRNA levels were analyzed using Real-Time PCR techniques.Results: Brain MRI without contrast led to an increase in protein levels of IL-6 in the peripheral serum, but did not change protein and mRNA levels of IL-10, IL-17A and TGF-β. IL-6 mRNA levels after MRI were higher in the participants with mild anxiety compared to those without anxiety.Conclusion: brain MRI without contrast can induce secretion of IL-6 and may be associated with its functions, such as development of plasma cells or induction of inflammation.

Image Denoising Using Non-Local Means (NLM) Approach in Magnetic Resonance (MR) Imaging: A Systematic Review

The non-local means (NLM) noise reduction algorithm is well known as an excellent technique for removing noise from a magnetic resonance (MR) image to improve the diagnostic accuracy. In this study, we undertook a systematic review to determine the effectiveness of the NLM noise reduction algorithm in MR imaging. A systematic literature search was conducted of three databases of publications dating from January 2000 to March 2020; of the 82 publications reviewed, 25 were included in this study. The subjects were categorized into four major frameworks and analyzed for each research result. Research in NLM noise reduction for MR images has been increasing worldwide; however, it was found to have slightly decreased since 2016. It was found that the NLM technique was most frequently used on brain images taken using the general MR imaging technique; these were most frequently performed during simultaneous real and simulated experimental studies. In particular, comparison parameters were frequently used to evaluate the effectiveness of the algorithm on MR images. The ultimate goal is to provide an accurate method for the diagnosis of disease, and our conclusion is that the NLM noise reduction algorithm is a promising method of achieving this goal.

Deep learning of brain magnetic resonance images: A brief review

Magnetic resonance imaging (MRI) is one of the most popular techniques in brain science and is important for understanding brain function and neuropsychiatric disorders. However, the processing and analysis of MRI is not a trivial task with lots of challenges. Recently, deep learning has shown superior performance over traditional machine learning approaches in image analysis. In this survey, we give a brief review of the recent popular deep learning approaches and their applications in brain MRI analysis. Furthermore, popular brain MRI databases and deep learning tools are also introduced. The strength and weaknesses of different approaches are addressed, and challenges as well as future directions are also discussed.

Recent Advances on Graphene Quantum Dots for Bioimaging Applications

Being a zero-dimensional (0D) nanomaterial of the carbon family, graphene quantum dots (GQDs) showed promising biomedical applications owing to their ultra-small size, non-toxicity, biocompatibility, excellent photo stability, tunable fluorescence, and water solubility, etc., thus capturing a considerable attention in biomedical field. This review summarizes the recent advances made in the research field of GQDs and place special emphasis on their bioimaging applications. We briefly introduce the synthesis strategies of GQDs, including top-down and bottom-up strategies. The bioimaging applications of GQDs are also discussed in detail, including optical [fluorescence (FL)], two-photon FL, magnetic resonance imaging (MRI), and dual-modal imaging. In the end, the challenges and future prospects to advance the clinical bioimaging applications of GQDs have also been addressed.

Effects of process parameters on the mechanical properties of additively manufactured Zr-1Mo alloy builds

In order to solve the artifact problem in magnetic resonance images, a low magnetic Zr-1Mo(wt%) alloy with high mechanical performance was successfully fabricated by laser powder bed fusion (L-PBF) using gas-atomized Zr-1Mo alloy powder. The as-built Zr-1Mo alloy showed superior strength and elongation compared to the as-cast Zr-1Mo alloy due to grain refinement and the inexistence of large casting defects. The microstructure of L-PBF-processed Zr-1Mo alloy builds was not sensitive to process parameters. On the other hand, morphology and distribution of defects, interstitials concentration, and crystallographic orientation comprehensively influenced the mechanical properties of the builds. Increasing interstitials concentration caused by increasing energy density render to increasing strength. Large pores caused by balling effect lead to a severe decrease of both strength and ductility of builds using high energy density (over 70.3 J·mm^-3) and high scanning speed (1050/1200 mm·s^-1). On the contrary, spherical pores possessing several microns in size has much less effect on mechanical properties than the large-size pores. There are two kinds of texture({1 1 0}_α texture and {1 1 0}_α+{1 0 2}_α bi-texture) were confirmed in this study. {1 1 0}_α texture contributed to the slight increase of elongation with increasing energy density in low scanning speed case (600/750 mm·s^-1) and the superior elongation of low scanning speed specimens compare to that of high scanning speed specimens in medium energy density range (about 48 J·mm^-3). From the viewpoints of the ultimate tensile strength(UTS) and elongation, it was found that an energy density of 84.4 mm·s^-1 with a scanning speed of 600 mm·s^-1 is preferable for the L-PBF-processed Zr-1Mo alloy in this study. These experimental results may provide direct guidelines regarding the applicability of Zr-1Mo alloy fabricated by L-PBF for biomedical applications.

Valid Exposure Protocols Needed in Magnetic Resonance Imaging Genotoxic Research

Several in vitro and in vivo studies have investigated if a magnetic resonance imaging (MRI) examination can cause DNA damage in human blood cells. However, the electromagnetic field (EMF) exposure that the cells received in the MR scanner was not sufficiently described. The first studies looking into this could be regarded as hypothesis-generating studies. However, for further exploration into the role of MRI exposure on DNA integrity, the exposure itself cannot be ignored. The lack of sufficient method descriptions makes the early experiments difficult, if not impossible, to repeat. The golden rule in all experimental work is that a study should be repeatable by someone with the right knowledge and equipment, and this is simply not the case with many of the recent studies on MRI and genotoxicity. Here we discuss what is lacking in previous studies, and how we think the next generation of in vitro and in vivo studies on MRI and genotoxicity should be performed. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.

Recent Advances in Molecular Imaging with Gold Nanoparticles

Gold nanoparticles (AuNP) have been extensively developed as contrast agents, theranostic platforms, and probes for molecular imaging. This popularity has yielded a large number of AuNP designs that vary in size, shape, surface functionalization, and assembly, to match very closely the requirements for various imaging applications. Hence, AuNP based probes for molecular imaging allow the use of computed tomography (CT), fluorescence, and other forms of optical imaging, photoacoustic imaging (PAI), and magnetic resonance imaging (MRI), and other newer techniques. The unique physicochemical properties, biocompatibility, and highly developed chemistry of AuNP have facilitated breakthroughs in molecular imaging that allow the detection and imaging of physiological processes with high sensitivity and spatial resolution. In this Review, we summarize the recent advances in molecular imaging achieved using novel AuNP structures, cell tracking using AuNP, targeted AuNP for cancer imaging, and activatable AuNP probes. Finally, the perspectives and current limitations for the clinical translation of AuNP based probes are discussed.

Reverse Microemulsion Synthesis of Fe3O4-Ag2S Heteronanocrystals for Dual-Modal Imaging-Guided Photothermal Tumor Ablation

Heterojunction nanomaterials have revealed a significant possibility in tumor diagnosis and therapeutic owing to tightly combining two parts of different chemical properties. Herein, we successfully synthesized heterogenous Fe₃O₄-Ag₂S nanocrystals through a reverse microemulsion. Based on the prepared heterostructure, a new drug nanoplatform was developed, which served as a contrast agent for T₂-weighted magnetic resonance imaging, computed tomography imaging, and photothermal imaging. In addition, these Fe₃O₄-Ag₂S heteronanocrystals exhibited a high photothermal conversion efficiency of 75.5% irradiated by a laser of 808 nm wavelength. After injection into glioma cancer mode in vivo, efficient tumor accumulation of Fe₃O₄-Ag₂S heteronanocrystals was observed under triple-modal imaging. The prepared heteronanocrystals further showed an excellent ablated tumor destruction effect through the generated hyperthermia with the irradiation of an 808 nm laser. Our work suggests that the potential of Fe₃O₄-Ag₂S heteronanocrystals may be a promising theranostic agent for multimodal imaging guidance and photothermal therapy toward cancer.

Use of ultrasound combined with magnetic resonance imaging for diagnosis of breast masses and fibroids

Objective

To investigate the clinical value of ultrasound plus magnetic resonance imaging (MRI) for the diagnosis of breast masses and fibroids.

Methods

Clinical data for 357 patients with breast masses diagnosed at our hospital were analyzed retrospectively. The diagnostic performances were compared between 243 patients who underwent routine ultrasound examinations (control group) and 114 patients who underwent routine ultrasound plus MRI (test group).

Results

The overall accordance rates of routine ultrasound and routine ultrasound plus MRI for the diagnosis of breast masses, based on postoperative pathological diagnoses, were 70.78% (172/243) and 90.35% (103/114). The addition of MRI significantly improved the overall diagnostic performance of routine ultrasound for breast masses. The diagnostic accordance rate of routine ultrasound for the diagnosis of breast fibroids (fibroadenomas) was 74.12% (63/85 cases) compared with 93.94% (31/33 cases) for routine ultrasound plus MRI. The diagnostic performance of routine ultrasound plus MRI was therefore also significantly higher than routine ultrasound alone for diagnosing breast fibroids.

Conclusions

Routine ultrasound plus MRI can greatly improve the diagnostic accordance rates for breast masses and fibroadenomas.

TOWARDS A PERSONALISED AND INTERACTIVE ASSESSMENT OF OCCUPATIONAL EXPOSURE TO MAGNETIC FIELD DURING DAILY ROUTINE IN MAGNETIC RESONANCE

Magnetic resonance imaging (MRI) is one of the most common sources of electromagnetic (EM) fields as a diagnostic technique widely used in medicine. MRI staff during the working day is constantly exposed to static and spatially heterogeneous magnetic field. Also, moving around the MRI room to perform their functions, workers are exposed to slowly time-varying magnetic fields that induce electrical currents and fields in the body. The development of new exposure assessment methodologies to collect exposure data at a personal level using simple everyday equipment is hence necessary, also in view of future epidemiological studies. This paper describes the design and testing of a novel device for assessing personal exposure to static and time-varying magnetic fields during daily clinical practice. The dosemeter will be also used to ensure effective training of technicians who will be instructed to avoid, where possible, risk behaviour in terms of high exposure.

Pros and cons of ultra-high-field MRI/MRS for human application

Magnetic resonance imaging and spectroscopic techniques are widely used in humans both for clinical diagnostic applications and in basic research areas such as cognitive neuroimaging. In recent years, new human MR systems have become available operating at static magnetic fields of 7 T or higher (≥300 MHz proton frequency). Imaging human-sized objects at such high frequencies presents several challenges including non-uniform radiofrequency fields, enhanced susceptibility artifacts, and higher radiofrequency energy deposition in the tissue. On the other side of the scale are gains in signal-to-noise or contrast-to-noise ratio that allow finer structures to be visualized and smaller physiological effects to be detected. This review presents an overview of some of the latest methodological developments in human ultra-high field MRI/MRS as well as associated clinical and scientific applications. Emphasis is given to techniques that particularly benefit from the changing physical characteristics at high magnetic fields, including susceptibility-weighted imaging and phase-contrast techniques, imaging with X-nuclei, MR spectroscopy, CEST imaging, as well as functional MRI. In addition, more general methodological developments such as parallel transmission and motion correction will be discussed that are required to leverage the full potential of higher magnetic fields, and an overview of relevant physiological considerations of human high magnetic field exposure is provided.

The potential toxic impact of different gadolinium-based contrast agents combined with 7-T MRI on isolated human lymphocytes

Background

To investigate a potentially amplifying genotoxic or cytotoxic effect of different gadolinium-based contrast agents (GBCAs) in combination with ultra-high-field 7-T magnetic resonance imaging (MRI) exposure in separated human peripheral blood lymphocytes.

Methods

This in vitro study was approved by the local ethics committee and written informed consent was obtained from all participants. Isolated lymphocytes from twelve healthy donors were incubated with gadobutrol, gadoterate meglumine, gadodiamide, gadopentetate dimeglumine, or gadoxetate either alone or combined with 7-T MRI (1 h). Deoxyribonucleic acid (DNA) double-strand breaks were assessed 15 min after MRI exposure by automated γH2AX foci quantification. Cytotoxicity was determined at later endpoints by Annexin V/propidium iodide apoptosis assay (24 h) and [³H]-thymidine proliferation test (72 h). As a reference, lymphocytes from four different donors were exposed analogously to iodinated contrast agents (iomeprol, iopromide) in combination with computed tomography.

Results

Baseline γH2AX levels (0.08 ± 0.02 foci/cell) were not significantly (p between 0.135 and 1.000) enhanced after administration of GBCAs regardless of MRI exposure. In contrast to the two investigated macrocyclic GBCAs, lymphocytes exposed to the three linear GBCAs showed a dose-dependent increase in apoptosis (maximum 186% of unexposed control, p < 0.001) and reduced proliferation rate (minimum 0.7% of unexposed control, p < 0.001). However, additional 7-T MRI co-exposure did not alter GBCA-induced cytotoxicity.

Conclusions

Exposure of lymphocytes to different GBCAs did not reveal significant induction of γH2AX foci, and enhanced cytotoxicity was only observed in lymphocytes treated with the linear GBCAs used in this study, independent of additional 7-T MRI co-exposure.

Electronic supplementary material

The online version of this article (10.1186/s41747-018-0069-y) contains supplementary material, which is available to authorized users.

Occupational exposure to electromagnetic fields in magnetic resonance environment: basic aspects and review of exposure assessment approaches

The purpose of this review is to make a contribution to build a comprehensive knowledge of the main aspects related to the occupational exposure to electromagnetic fields (EMFs) in magnetic resonance imaging (MRI) environments. Information has been obtained from original research papers published in international peer-reviewed journals in the English language and from documents published by governmental bodies and authorities. An overview of the occupational exposure scenarios to static magnetic fields, motion-induced, time-varying magnetic fields, and gradient and radiofrequency fields is provided, together with a summary of the relevant regulation for limiting exposure. A particular emphasis is on reviewing the main EMF exposure assessment approaches found in the literature. Exposure assessment is carried out either by measuring the unperturbed magnetic fields in the MRI rooms, or by personal monitoring campaigns, or by the use of numerical methods. A general lack of standardization of the procedures and technologies adopted for exposure assessment has emerged, which makes it difficult to perform a direct comparison of results from different studies carried out by applying different assessment strategies. In conclusion, exposure assessment approaches based on data collection and numerical models need to be better defined in order to respond to specific research questions. That would provide for a more complete characterization of the exposure patterns and for identification of the factors determining the exposure variability. Graphical abstract Main approaches adopted in the literature to perform occupational exposure assessment to electromagnetic fields (EMFs) in magnetic resonance imaging (MRI) environments. SMF: static magnetic field; GMF: gradient magnetic fields; RF: radio-frequencies.

Gadolinium-enhanced cardiac MR exams of human subjects are associated with significant increases in the DNA repair marker 53BP1, but not the damage marker γH2AX

Magnetic resonance imaging is considered low risk, yet recent studies have raised a concern of potential damage to DNA in peripheral blood leukocytes. This prospective Institutional Review Board-approved study examined potential double-strand DNA damage by analyzing changes in the DNA damage and repair markers γH2AX and 53BP1 in patients who underwent a 1.5 T gadolinium-enhanced cardiac magnetic resonance (MR) exam. Sixty patients were enrolled (median age 55 years, 39 males). Patients with history of malignancy or who were receiving chemotherapy, radiation therapy, or steroids were excluded. MR sequence data were recorded and blood samples obtained immediately before and after MR exposure. An automated immunofluorescence assay quantified γH2AX or 53BP1 foci number in isolated peripheral blood mononuclear cells. Changes in foci number were analyzed using the Wilcoxon signed-rank test. Clinical and MR procedural characteristics were compared between patients who had a >10% increase in γH2AX or 53BP1 foci numbers and patients who did not. The number of γH2AX foci did not significantly change following cardiac MR (median foci per cell pre-MR = 0.11, post-MR = 0.11, p = .90), but the number of 53BP1 foci significantly increased following MR (median foci per cell pre-MR = 0.46, post-MR = 0.54, p = .0140). Clinical and MR characteristics did not differ significantly between patients who had at least a 10% increase in foci per cell and those who did not. We conclude that MR exposure leads to a small (median 25%) increase in 53BP1 foci, however the clinical relevance of this increase is unknown and may be attributable to normal variation instead of MR exposure.

Exposure Assessment and Biomonitoring of Workers in Magnetic Resonance Environment: An Exploratory Study

Magnetic resonance imaging (MRI) has evolved rapidly over the past few decades as one of the most flexible tools in medical research and diagnostic imaging. MRI facilities are important sources of multiple exposure to electromagnetic fields for both patients and health-care staff, due to the presence of electromagnetic fields of multiple frequency ranges, different temporal variations, and field strengths. Due to the increasing use and technological advancements of MRI systems, clearer insights into exposure assessment and a better understanding of possible harmful effects due to long-term exposures are highly needed. In the present exploratory study, exposure assessment and biomonitoring of MRI workers at the Radio-diagnostics Unit of the National Cancer Institute of Naples "Pascale Foundation" (Naples, Italy) have been carried out. In particular, exposure to the MRI static magnetic field (SMF) has been evaluated by means of personal monitoring, while an application tool has been developed to provide an estimate of motion-induced, time-varying electric fields. Measurement results have highlighted a high day-to-day and worker-to-worker variability of the exposure to the SMF, which strongly depends on the characteristics of the environment and on personal behaviors, and the developed application tool can be adopted as an easy-to-use tool for rapid and qualitative evaluation of motion-induced, time-varying electric field exposure. Regarding biomonitoring, the 24 workers of the Radio-diagnostics Unit were enrolled to evaluate both spontaneous and mitomycin C-induced chromosomal fragility in human peripheral blood lymphocytes, by means of the cytokinesis-block micronucleus assay. The study subjects were 12 MRI workers, representative of different professional categories, as the exposed group, and 12 workers with no MRI exposure history, as the reference group. The results show a high worker-to-worker variability for both field exposure assessment and biomonitoring, as well as several critical issues and practicalities to be faced with in this type of investigations. The procedures for risk assessment and biomonitoring proposed here can be used to inform future research in this field, which will require a refinement of exposure assessment methods and an enlargement of the number of subjects enrolled in the biomonitoring study to gain robust statistics and reliable results.

OCCUPATIONAL EXPOSURE OF NMR SPECTROMETRISTS TO STATIC AND RADIOFREQUENCY FIELDS

Occupational exposure to static and radiofrequency fields emitted by nuclear magnetic resonance spectrometers was assessed through systematic field metering during operation of 19 devices in nine research centers. Whereas no measurable levels of radiofrequency radiation were registered outside the spectrometers, significant exposure to static field was detected, with maximum values recorded at the user's hand (B = 683.00 mT) and head-thorax (B = 135.70 mT) during spectrometer manipulation. All values were well below the exposure limits set by the European standard for workers protection against the effects of acute field exposure only. As for potential effects of chronic exposure, waiting for more complete knowledge, adoption of technical and operational strategies for exposure minimizing is advisable. In this respect, the data revealed that compared with standard magnetic shielding, ultrashield technology allows a 20-65-fold reduction of the field strength received by the operator.

Nanoparticles as contrast agents for brain nuclear magnetic resonance imaging in Alzheimer's disease diagnosis

Nuclear Magnetic Resonance Imaging (MRI) of amyloid plaques is a powerful non-invasive approach for the early and accurate diagnosis of Alzheimer's disease (AD) along with clinical observations of behavioral changes and cognitive impairment. The present article aims at giving a critical and comprehensive review of recent advances in the development of nanoparticle-based contrast agents for brain MRI. Nanoparticles considered for the MRI of AD must comply with a highly stringent set of requirements including low toxicity and the ability to cross the blood-brain-barrier. In addition, to reach an optimal signal-to-noise ratio, they must exhibit a specific ability to target amyloid plaques, which can be achieved by grafting antibodies, peptides or small molecules. Finally, we propose to consider new directions for the future of MRI in the context of Alzheimer's disease, in particular by enhancing the performances of contrast agents and by including therapeutic functionalities following a theranostic strategy.

ICNIRP Statement on Diagnostic Devices Using Non-ionizing Radiation: Existing Regulations and Potential Health Risks

Use of non-ionizing radiation (NIR) for diagnostic purposes allows non-invasive assessment of the structure and function of the human body and is widely employed in medical care. ICNIRP has published previous statements about the protection of patients during medical magnetic resonance imaging (MRI), but diagnostic methods using other forms of NIR have not been considered. This statement reviews the range of diagnostic NIR devices currently used in clinical settings; documents the relevant regulations and policies covering patients and health care workers; reviews the evidence around potential health risks to patients and health care workers exposed to diagnostic NIR; and identifies situations of high NIR exposure from diagnostic devices in which patients or health care workers might not be adequately protected by current regulations. Diagnostic technologies were classified by the types of NIR that they employ. The aim was to describe the techniques in terms of general device categories which may encompass more specific devices or techniques with similar scientific principles. Relevant legally-binding regulations for protection of patients and workers and organizations responsible for those regulations were summarized. Review of the epidemiological evidence concerning health risks associated with exposure to diagnostic NIR highlighted a lack of data on potential risks to the fetus exposed to MRI during the first trimester, and on long-term health risks in workers exposed to MRI. Most of the relevant epidemiological evidence that is currently available relates to MRI or ultrasound. Exposure limits are needed for exposures from diagnostic technologies using optical radiation within the body. There is a lack of data regarding risk of congenital malformations following exposure to ultrasound in utero in the first trimester and also about the possible health effects of interactions between ultrasound and contrast media.

Classification of brain disease in magnetic resonance images using two-stage local feature fusion

BACKGROUND

Many classification methods have been proposed based on magnetic resonance images. Most methods rely on measures such as volume, the cerebral cortical thickness and grey matter density. These measures are susceptible to the performance of registration and limited in representation of anatomical structure. This paper proposes a two-stage local feature fusion method, in which deformable registration is not desired and anatomical information is represented from moderate scale.

METHODS

Keypoints are firstly extracted from scale-space to represent anatomical structure. Then, two kinds of local features are calculated around the keypoints, one for correspondence and the other for representation. Scores are assigned for keypoints to quantify their effect in classification. The sum of scores for all effective keypoints is used to determine which group the test subject belongs to.

RESULTS

We apply this method to magnetic resonance images of Alzheimer's disease and Parkinson's disease. The advantage of local feature in correspondence and representation contributes to the final classification. With the help of local feature (Scale Invariant Feature Transform, SIFT) in correspondence, the performance becomes better. Local feature (Histogram of Oriented Gradient, HOG) extracted from 16×16 cell block obtains better results compared with 4×4 and 8×8 cell block.

DISCUSSION

This paper presents a method which combines the effect of SIFT descriptor in correspondence and the representation ability of HOG descriptor in anatomical structure. This method has the potential in distinguishing patients with brain disease from controls.

Comments on potential health effects of MRI-induced DNA lesions: quality is more important to consider than quantity

Magnetic resonance imaging (MRI) is increasingly being used in cardiology to detect heart disease and guide therapy. It is mooted to be a safer alternative to imaging techniques, such as computed tomography (CT) or coronary angiographic imaging. However, there has recently been an increased interest in the potential long-term health risks of MRI, especially in the light of the controversy resulting from a small number of research studies reporting an increase in DNA damage following exposure, with calls to limit its use and avoid unnecessary examination, according to the precautionary principle. Overall the published data are somewhat limited and inconsistent; the ability of MRI to produce DNA lesions has yet to be robustly demonstrated and future experiments should be carefully designed to optimize sensitivity and benchmarked to validate and assess reproducibility. The majority of the current studies have focussed on the initial induction of DNA damage, and this has led to comparisons between the reported induction of γH2AX and implied double-strand break (DSB) yields produced following MRI with induction by imaging techniques using ionizing radiation. However, γH2AX is not only a marker of classical double-ended DSB, but also a marker of stalled replication forks and in certain circumstances stalled DNA transcription. Additionally, ionizing radiation is efficient at producing complex DNA damage, unique to ionizing radiation, with an associated reduction in repairability. Even if the fields associated with MRI are capable of producing DNA damage, the lesions produced will in general be simple, similar to those produced by endogenous processes. It is therefore inappropriate to try and infer cancer risk by simply comparing the yields of γH2AX foci or DNA lesions potentially produced by MRI to those produced by a given exposure of ionizing radiation, which will generally be more biologically effective and have a greater probability of leading to long-term health effects. As a result, it is important to concentrate on more relevant downstream end points (e.g. chromosome aberration production), along with potential mechanisms by which MRI may lead to DNA lesions. This could potentially involve a perturbation in homeostasis of oxidative stress, modifying the background rate of endogenous DNA damage induction. In summary, what the field needs at the moment is more research and less fear mongering.

Impact of in Vivo High-Field-Strength and Ultra-High-Field-Strength MR Imaging on DNA Double-Strand-Break Formation in Human Lymphocytes

Purpose To determine the impact of different magnetic field strengths (1, 1.5, 3, and 7 T) and the effect of contrast agent on DNA double-strand-break (DSB) formation in patients undergoing magnetic resonance (MR) imaging. Materials and Methods This in vivo study was approved by the local ethics committee, and written informed consent was obtained from each patient. To analyze the level of DNA DSBs, peripheral blood mononuclear cells were isolated from blood samples drawn directly before, as well as 5 minutes and 30 minutes after MR imaging examination. After performing γH2AX immunofluorescence staining, DSBs were quantified with automated digital microscopy. MR group consisted of 43 patients (22 women, 21 men; mean age, 46.1 years; range, 20-77 years) and was further subdivided according to the applied field strength and administration of contrast agent. Additionally, 10 patients undergoing either unenhanced or contrast material-enhanced computed tomography (CT) served as positive control subjects. Statistical analysis was performed with Friedman test. Results Whereas DSBs in lymphocytes increased after CT exposure (before MR imaging: 0.14 foci per cell ± 0.05; 5 minutes after: 0.26 foci per cell ± 0.07; 30 minutes after: 0.24 foci per cell ± 0.07; P ≤ .05), no alterations were observed in patients examined with MR imaging (before MR imaging: 0.13 foci per cell ± 0.02; 5 minutes after: 0.12 foci per cell ± 0.02; 30 minutes after: 0.11 foci per cell ± 0.02; P > .05). Differentiated analysis of MR imaging subgroups again revealed no significant changes in γH2AX level. Conclusion Analysis of γH2AX foci showed no evidence of DSB induction after MR examination, independent of the applied field strength and administration of gadolinium-based contrast agent.

Classification of brain disease from magnetic resonance images based on multi-level brain partitions

In this paper, we present a classification method based on the multi-level brain partitions. Bag-of-visual-words model is used. Firstly, the representative SIFT features are extracted from brain template as the basic visual words. Secondly, individual MR images are described using the basic visual words and support vector machine classifiers are trained for different brain partitions respectively. Thirdly, the final classification is derived from the combination of multiple classifiers. We apply this method to MR images of Alzheimer's disease and Parkinson's disease. The results demonstrate that the multi-level partitions favors the classification accuracy of brain disease from MR images.

Fluorescent lifetime imaging microscopy using Europium complexes improves atherosclerotic plaques discrimination

The objective of this study is to characterize arterial tissue with and without atherosclerosis by fluorescence lifetime imaging microscopy (FLIM) using Europium Chlortetracycline complex (EuCTc) as fluorescent marker. For this study, twelve rabbits were randomly divided into a control group (CG) and an experimental group (EG), where they were fed a normal and hypercholesterolemic diet, respectively, and were treated for 60 days. Cryosections of the aortic arch specimens were cut in a vertical plane, mounted on glass slides, and stained with Europium (Eu), Chlortetracycline (CTc), Europium Chlortetracycline (EuCTc), and Europium Chlortetracycline Magnesium (EuCTcMg) solutions. FLIM images were obtained with excitation at 405 nm. The average autofluorescence lifetime within plaque depositions was ~1.36 ns. Reduced plaque autofluorescence lifetimes of 0.23 and 0.31 ns were observed on incubation with EuCTc and EuCTcMg respectively. It was observed a quenching of collagen, cholesterol and TG emission spectra increasing EuCTc concentration. The drastic reduction in fluorescence lifetimes is due to a resonant energy transfer between collagen, triglycerides, cholesterol and europium complexes, quenching fluorescence.