Search Results (621)

Breast cancer is the leading cause of cancer-related mortality among women world-wide, and early screening is critical for improving patient survival. Medical imaging plays a central role in breast cancer screening, diagnosis, and treatment monitoring. However, conventional imaging modalities—including mammography, ultrasound, and magnetic resonance imaging—face limitations such as low diagnostic specificity, relatively slow imaging speed, ionizing radiation exposure, and dependence on exogenous contrast agents. Photoacoustic imaging (PAI), a novel hybrid imaging technique that combines optical contrast with ultrasonic spatial resolution, has shown great promise in addressing these challenges. By revealing anatomical, functional, and molecular features of the breast tumor microenvironment, PAI offers high spatial resolution, rapid imaging, and minimal operator dependence. This review outlines the fundamental principles of PAI and systematically examines recent advances in its application to breast cancer screening, diagnosis, and therapeutic evaluation. Furthermore, we discuss the translational potential of PAI as an emerging breast imaging modality, complementing existing clinical techniques. Full article

Background/Objectives: Magnetic resonance imaging (MRI) is a powerful, non-invasive diagnostic tool capable of capturing detailed anatomical and physiological information. MRI contrast agents enhance image contrast but, especially linear gadolinium-based compounds, have been associated with safety concerns. This has prompted interest in alternative contrast agents. Manganese-based contrast agents offer a promising substitute, owing to manganese’s favorable magnetic properties, natural biological role, and strong T1 relaxivity. This review aims to critically assess the structure, mechanisms, applications, and challenges of manganese-based contrast agents in MRI. Methods: This review synthesizes findings from preclinical and clinical studies involving various types of manganese-based contrast agents, including small-molecule chelates, nanoparticles, theranostic platforms, responsive agents, and controlled-release systems. Special attention is given to pharmacokinetics, biodistribution, and safety evaluations. Results: Mn-based agents demonstrate promising imaging capabilities, with some achieving relaxivity values comparable to gadolinium compounds. Targeted uptake mechanisms, such as hepatocyte-specific transport via organic anion-transporting polypeptides, allow for enhanced tissue contrast. However, concerns remain regarding the in vivo release of free Mn²⁺ ions, which could lead to toxicity. Preliminary toxicity assessments report low cytotoxicity, but further comprehensive long-term safety studies should be carried out. Conclusions: Manganese-based contrast agents present a potential alternative to gadolinium-based MRI agents pending further validation. Despite promising imaging performance and biocompatibility, further investigation into stability and safety is essential. Additional research is needed to facilitate the clinical translation of these agents. Full article

Background: Singlet oxygen (¹O₂) generation in biological samples remains a significant challenge. Studying the mechanism of ¹O₂ action during photodynamic therapy (PDT) in atherosclerotic plaques in vitro represents an innovative cardiological approach. Atherosclerosis, a chronic and progressive disease, is characterized by plaque buildup inside arterial walls. Objectives: This study focused on the use of spin–lattice (T₁) and spin–spin (T₂) relaxation times measured by Magnetic Resonance Imaging (MRI) before and after the administration of indocyanine green-mediated PDT (ICG-PDT). Methods: To enhance visualization of morphological changes in atherosclerotic plaques, the clinically approved MRI contrast agent Gadovist was utilized. A total of 12 atherosclerotic plaque samples were collected from six patients undergoing endarterectomy. The generation of ¹O₂ in these plaques was assessed using quantitative MRI measurements and microscopic imaging, which visualized structural changes induced by PDT. Results: This research explores the potential of T₁ and T₂ relaxation times as indicators of PDT efficacy, while Gadovist helped provide evidence of ¹O₂ diffusion within the samples. Conclusions: Considering advancements in modern treatment, PDT may offer a novel approach for targeting atherosclerosis. Full article

Magnetotactic bacteria (MTB), a unique group of Gram-negative prokaryotes, have the remarkable ability to biomineralize magnetic nanoparticles (MNPs) intracellularly, making them promising candidates for various biomedical applications such as biosensors, drug delivery, imaging contrast agents, and cancer-targeted therapies. To fully exploit the potential of MTB, a precise understanding of the structural, surface, and functional properties of these biologically produced nanoparticles is required. Given these concerns, this review provides a focused synthesis of the most widely used microscopic and spectroscopic methods applied in the characterization of MTB and their associated MNPs, covering the latest research from January 2022 to May 2025. Specifically, various optical microscopy techniques (e.g., transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM)) and spectroscopic approaches (e.g., localized surface plasmon resonance (LSPR), surface-enhanced Raman scattering (SERS), and X-ray photoelectron spectroscopy (XPS)) relevant to ultrasensitive MTB biosensor development are herein discussed and compared in term of their advantages and disadvantages. Overall, the novelty of this work lies in its clarity and structure, aiming to consolidate and simplify access to the most current and effective characterization techniques. Furthermore, several gaps in the characterization methods of MTB were identified, and new directions of methods that can be integrated into the study, analysis, and characterization of these bacteria are suggested in exhaustive manner. Finally, to the authors’ knowledge, this is the first comprehensive overview of characterization techniques that could serve as a practical resource for both younger and more experienced researchers seeking to optimize the use of MTB in the development of advanced biosensing systems and other biomedical tools. Full article

Glutamate, the primary excitatory neurotransmitter in the central nervous system, plays a pivotal role in synaptic signaling, learning, and memory. Abnormal glutamate levels are implicated in various neurological disorders, including epilepsy, Alzheimer’s disease, and ischemic stroke. Despite the utility of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) in diagnosing such conditions, the development of effective glutamate-sensitive contrast agents remains a challenge. In this study, we present ultrasmall, citric acid-coated superparamagnetic iron oxide nanoparticles (CA-SPIONs) as highly selective and sensitive MRS probes for glutamate detection. These 5 nm magnetite CA-SPIONs exhibit a stable dispersion in physiological buffers and undergo aggregation in the presence of glutamate, significantly enhancing the T₂ MRS contrast power. At physiological glutamate levels, the CA-SPIONs yielded a pronounced signal change ratio of nearly 60%, while showing a negligible response to other neurotransmitters such as GABA and dopamine. Computational simulations confirmed the mechanism of glutamate-mediated aggregation and its impact on transversal relaxation rates and relaxivities. The sensitivity and selectivity of CA-SPIONs underscore their potential as eco-friendly, iron-based alternatives for future neurological sensing applications targeting glutamatergic dysfunction. Full article

Synthesized Ln₂O₃ (Ln = La, Nd or Gd) nanoparticles with sizes of 1–3 nm, 5–6 nm and 10–15 nm were stabilized by carbon nanoflakes (CNFs). The weight content of Ln₂O₃ in the Ln₂O₃/CNF composites was 20–50 wt. %, which makes these composites potentially suitable for practical use as computed tomography and magnetic resonance imaging contrast agents. The structure of CNFs and Ln₂O₃/CNF composites was investigated by X-ray diffraction data, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). The EPR spectra of raw CNFs were silent. The oxidation of the CNF surface resulted in the appearance of paramagnetic centers associated with two types of unpaired electrons in the carbon support. After impregnation of the CNFs with the Ln³⁺ ion solution, the number of unpaired electrons was reduced, presumably due to the formation of C–O–Ln bonds. All Ln³⁺ ions changed the composites’ EPR spectra by reducing the number of unpaired electrons in the CNF structure. Full article

Carbon nanodots have recently attracted attention as fluorescence imaging probes and magnetic resonance imaging (MRI) contrast agents in diagnostic and therapeutic applications due to their unique optical properties. In this work we report the synthesis of biocompatible Mn (II)-doped carbon nanodots and their performance as fluorescence and MRI contrast agents in in vitro assays. The thermal decomposition of a Diphenylhydantoin–Mn(II) complex assured the incorporation of manganese (II) ions in the carbon dots. The obtained materials display a favorable spin density for MRI applications. The synthesized Mn(II)-CNDs also displayed remarkable photoluminescence, with a bright blue emission and good response in in vitro fluorescence imaging. Cytotoxicity investigations revealed good cell viability on malignant melanoma cell lines in a large concentration range. A cytotoxic effect was observed for MG-63 osteosarcoma and breast adenocarcinoma cell lines. The in vitro MRI assays demonstrated the potentialities of the Mn(II)-CNDs as T2 contrast agents at low dosages, with relaxivity values higher than those of commercial ones. Due to the simplicity of their synthetic pathway and their low cytotoxicity, the prepared Mn(II)-CNDs are potential alternatives to currently used contrast agents based on gadolinium complexes. Full article

Background: Carnosine is a multimodal pleotropic endogenous molecule that exhibits properties that make it a compelling therapeutic agent for further evaluation in a number of diseases. However, little data currently exists on its pharmacokinetic profile, maximum tolerated doses, side effects and whether oral administration can lead to elevated brain concentrations. Method: To investigate this, sixteen healthy volunteers underwent a single dose-escalation study of oral carnosine to establish safety, tolerability, and pharmacokinetics. A subset (n = 5) underwent Proton Magnetic Resonance Imaging (MRI) spectroscopy to evaluate the effect of oral dosing on brain carnosine concentrations, and another subset (n = 4) completed a long-term (4-week) dosing study. Results: Oral carnosine was safe and well tolerated up to a dose of 10 g. At doses of 15 g, the frequency of adverse events became unacceptably high, with 77% of participants experiencing side effects, most commonly headache (43.5%), nausea (21.7%) and paraesthesia (21.7%). While pharmacokinetic profiles varied between individuals, peak plasma concentrations occurred within the first hour of dosing. Little circulating carnosine was detectable beyond 4 h. Brain carnosine concentration increased at 1 h post-dose but reverted to baseline values by 5 h. Long-term dosing at 5 g twice daily did not result in any adverse events. Conclusions: Our data will inform dosing interventions in future clinical trials of this exciting agent. Full article

Superparamagnetic iron oxide (SPIO) nanoparticles are a promising platform for drug delivery and magnetic resonance imaging (MRI). However, complement activation and immune recognition remain major barriers to their clinical translation. Previously, we reported that dextran-coated SPIO nanoworms (NWs) trigger potent complement activation and infusion reactions. Here, we systematically map the temporal sequence of immune events following SPIO NW administration, including C3 opsonization, granulocyte uptake, and cytokine release. In both in vitro and in vivo models, C3 deposition occurred rapidly, peaking at approximately 5 min post-incubation or post-injection. Higher Fe/plasma ratios led to reduced C3 deposition per particle, although the absolute amount of C3 bound was greater in vivo than in vitro. Notably, C3 dissociation from the particle surface exhibited a consistent half-life of ~14 min, independent of the NW injected dose and circulation time. Immune uptake by blood granulocytes was delayed relative to opsonization, becoming prominent only at 60 min post-injection. Further, cytokine release, measured by plasma IL-6 levels, displayed an even slower profile, with peak expression at 6 h post-injection. Together, these results reveal a distinct sequential immune response to SPIO NWs: rapid C3 opsonization, delayed cellular uptake, and late cytokine response. Understanding these dynamics provides a basis for developing strategies to inhibit complement activation and improve the hemocompatibility of SPIO-based theranostic agents. Full article

Neuroinflammation, triggered by lipoxygenase (LOX), contributes to Alzheimer’s disease (AD) progression. Overexpression of LOX-5 in patients with AD serum highlights its role. This study assessed the efficacy of the LOX-inhibitor-peptide YWCS in an AD rat model induced by Aβ_25–35 injection. Cognitive tests, magnetic resonance imaging (MRI) scans, and molecular analyses were conducted. YWCS treatment significantly improved cognitive function, as evidenced by improved performance in the open field, novel object recognition, elevated plus maze, and Morris water maze tests. MRI scans revealed hippocampal shrinkage in AD rats and no changes were observed from YWCS treatment. Molecular analysis revealed altered expression of LOX-5, LOX-12, Aβ, γ-secretase components, p-Tau¹⁸¹, Akt, p-Akt, and p53 in AD rats. Immunofluorescence staining confirmed increased expression of LOX, Aβ, and p-Tau¹⁸¹ in the hippocampus of AD rats, which was reduced by YWCS treatment. Serum LOX levels were elevated in AD rats and significantly decreased after YWCS treatment, aligning with previous findings in human AD patients and AD cell models. YWCS offered improvements in behavioral and inflammatory marker regulation and also prevented progression of the disease, as shown by MRI results. These results suggest that YWCS, by targeting LOX, has the potential to be a promising therapeutic agent for AD. Full article

The hypertrophic cardiomyopathy (HCM) clinical phenotype includes sarcomeric HCM, which is the most common form of inherited cardiomyopathy with a population prevalence of 1:500, and phenocopies such as cardiac amyloidosis and Anderson–Fabry disease, which are considered rare diseases. Identification of cardiac and non-cardiac red flags in the context of multi-organ syndrome, multimodality imaging, including echocardiography, cardiac magnetic resonance, and genetic testing, has a central role in the diagnostic pathway. Identifying the specific disease underlying the hypertrophic phenotype is very important since many disease-modifying therapies are currently available, and phase 3 trials for new treatments have been completed or are ongoing. In particular, many chemotherapy agents (alkylating agents, proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies targeting clonal cells) allowing one to treat AL amyloidosis, transthyretin stabilizers (tafamidis and acoramidis), and gene silencers (patisiran and vutrisiran) are available in transthyretin cardiac amyloidosis, and enzyme replacement therapies (agalsidase-alpha, agalsidase-beta, and pegunigalsidase-alpha) or oral chaperone therapy (migalastat) can be used in Anderson–Fabry disease. In addition, the introduction of cardiac myosin inhibitors (mavacamten and aficamten) has deeply modified the treatment of hypertrophic obstructive cardiomyopathy. The aim of this review is to describe the new disease-modifying treatments available in HCM and phenocopies in light of current scientific evidence. Full article

Current treatments fail to prevent long-term consequences induced by a severe traumatic brain injury (TBI). This study aimed to evaluate the efficacy of repetitive intranasal administration of NeuroEPO (a derivative of erythropoietin) on long-term alterations after a severe TBI induced by the application of a lateral fluid percussion in male rats. A otal of 30–31 days after the trauma, TBI+vehicle group showed sensorimotor dysfunction (Neuroscore, p < 0.0009; beam walking test, p < 0.0001 vs. Sham+vehicle group) and depressive-like behavior suggested by increased immobility (p = 0.0009 vs. baseline) during the forced swim test. Rats also showed increased production of malondialdehyde (a marker of oxidative damage), increased catalase activity (an antioxidant enzyme), and atrophy of brain areas evaluated with Magnetic Resonance Imaging 31 days after the trauma. TBI+NeuroEPO group received intranasal administration of NeuroEPO (0.136 mg/kg) starting 3 h post-TBI and continued every 8 h for four days. This group showed less sensorimotor dysfunction (Neuroscore, p = 0.020; beam walking test, p = 0.001, vs. TBI+vehicle group) and normal immobility behavior (p = 0.998 vs. Sham+vehicle group). Levels of malondialdehyde and catalase as well as the volume of brain structures of this group were like the Sham+vehicle group. These findings support the potential of NeuroEPO as a therapeutic agent to reduce long-term consequences of TBI. Full article

Magnetic Resonance Imaging (MRI) services in high-complexity hospitals often suffer from operational inefficiencies, including suboptimal MRI machine utilization, prolonged patient waiting times, and inequitable service delivery across clinical priority levels. Addressing these challenges requires intelligent scheduling strategies capable of dynamically managing patient waitlists based on clinical urgency while optimizing resource allocation. In this study, we propose a novel framework that integrates a digital twin (DT) of the MRI operational environment with a reinforcement learning (RL) agent trained via Deep Q-Networks (DQN). The digital twin simulates realistic hospital dynamics using parameters extracted from a MRI publicly available dataset, modeling patient arrivals, examination durations, MRI machine reliability, and clinical priority stratifications. Our strategy learns policies that maximize MRI machine utilization, minimize average waiting times, and ensure fairness by prioritizing urgent cases in the patient waitlist. Our approach outperforms traditional baselines, achieving a 14.5% increase in MRI machine utilization, a 44.8% reduction in average patient waiting time, and substantial improvements in priority-weighted fairness compared to First-Come-First-Served (FCFS) and static priority heuristics. Our strategy is designed to support hospital deployment, offering scalability, adaptability to dynamic operational conditions, and seamless integration with existing healthcare information systems. By advancing the use of digital twins and reinforcement learning in healthcare operations, our work provides a promising pathway toward optimizing MRI services, improving patient satisfaction, and enhancing clinical outcomes in complex hospital environments. Full article

Radiological assessment following pancreaticoduodenectomy is critical for the prompt diagnosis and management of postoperative complications, significantly influencing patient outcomes. Pancreaticoduodenectomy, or the Whipple procedure, is the standard surgical intervention for pancreatic and periampullary malignancies, but it involves notable risks, especially from complications like fistulas, bleeding, or leakage. Cross-sectional imaging, particularly contrast-enhanced computed tomography, serves as the primary diagnostic tool due to its rapid acquisition, high resolution, and effective delineation of postoperative anatomy and complications. Magnetic resonance imaging (with cholangiopancreatography and hepatobiliary contrast agents) complements CT by providing superior contrast resolution for specific complications, notably in the biliary system and pancreatic duct. This narrative review discusses various imaging techniques and their applications, highlighting characteristic radiological features of common postoperative complications. It underscores the importance of a multidisciplinary approach, emphasizing close collaboration between radiologists and surgeons to optimize surgical decision-making and improve patient management post-pancreatic surgery. Full article

Background and Purpose: Undescended testes (UDT) is recognized as the most prevalent anomaly of the male genitalia and presents a significant risk factor for long-term complications, including infertility and testicular cancer. Currently, there is no consensus on the necessity of imaging in the management of UDT, nor is there agreement on which imaging modality is preferred or to what extent these tests offer real added value in the clinical setting. This review aims to evaluate the various imaging options available in the management of cryptorchidism, discussing their utility, advantages, and disadvantages compared to exploratory laparoscopy. Methods: We conducted a PubMed search using the following search terms: [“undescended testis”] OR [(“cryptorchidism”) OR (“diagnostic imaging”)] OR [(“Ultrasound”), OR (“CT scan”) OR (“MRI”)] AND [“laparoscopy”]. We analyzed 90 full articles, excluding irrelevant ones, and, in total, 18 publications were included in this review. Results: Ultrasound (US) is the most commonly used technique due to its non-invasive nature and absence of ionizing radiation. It is particularly beneficial in cases of non-palpable UDT. However, its main limitation lies in the difficulty in accurately locating UDT, especially when they are situated outside the inguinal region. Computed tomography (CT) scans serve as a crucial diagnostic tool, particularly for testes located below the internal inguinal ring. While CT exhibits comparable accuracy in detecting UDT, the need for sedation or general anesthesia, along with the costs and potential risks of secondary malignancy due to radiation exposure, does not favor its routine use. Magnetic resonance imaging (MRI) offers higher sensitivity than US and does not utilize ionizing radiation or intravascular contrast agents. It allows for the generation of multiplanar images, thereby providing improved tissue characterization. However, limitations include prolonged scan durations, the potential for motion artifacts during imaging, the need for sedation, and higher costs. Laparoscopy has been shown to provide better accuracy, offering both diagnostic and therapeutic benefits, particularly in cases of non-palpable UDT. It is widely regarded as the gold standard in achieving clear diagnostic and definitive therapeutic procedures and has demonstrated its utility in determining the anatomical position of intra-abdominal testes, owing to its magnification capabilities and minimally invasive approach. Conclusions: Achieving a correct and comprehensive diagnosis of cryptorchidism requires the medical team to decide on the appropriate imaging studies, as these will not significantly influence or alter the therapeutic decision-making process. It is unlikely that medical practice will eliminate imaging studies before a surgical decision is made in the near future. Therefore, a multidisciplinary approach that includes clinical examination, imaging, and diagnostic laparoscopy remains essential for the accurate management of UDT. Full article