Application Of Magnetic Resonance Imaging Research Articles

Deep Learning Reconstruction Combined With Conventional Acceleration Improves Image Quality of 3 T Brain MRI and Does Not Impact Quantitative Diffusion Metrics.

Deep learning reconstruction of magnetic resonance imaging (MRI) allows to either improve image quality of accelerated sequences or to generate high-resolution data. We evaluated the interaction of conventional acceleration and Deep Resolve Boost (DRB)-based reconstruction techniques of a single-shot echo-planar imaging (ssEPI) diffusion-weighted imaging (DWI) on image quality features in cerebral 3 T brain MRI and compared it with a state-of-the-art DWI sequence. In this prospective study, 24 patients received a standard of care ssEPI DWI and 5 additional adapted ssEPI DWI sequences, 3 of those with DRB reconstruction. Qualitative analysis encompassed rating of image quality, noise, sharpness, and artifacts. Quantitative analysis compared apparent diffusion coefficient (ADC) values region-wise between the different DWI sequences. Intraclass correlations, paired sampled t test, Wilcoxon signed rank test, and weighted Cohen κ were used. Compared with the reference standard, the acquisition time was significantly improved in accelerated DWI from 75 seconds up to 50% (39 seconds; P < 0.001). All tested DRB-reconstructed sequences showed significantly improved image quality, sharpness, and reduced noise (P < 0.001). Highest image quality was observed for the combination of conventional acceleration and DL reconstruction. In singular slices, more artifacts were observed for DRB-reconstructed sequences (P < 0.001). While in general high consistency was found between ADC values, increasing differences in ADC values were noted with increasing acceleration and application of DRB. Falsely pathological ADCs were rarely observed near frontal poles and optic chiasm attributable to susceptibility-related artifacts due to adjacent sinuses. In this comparative study, we found that the combination of conventional acceleration and DRB reconstruction improves image quality and enables faster acquisition of ssEPI DWI. Nevertheless, a tradeoff between increased acceleration with risk of stronger artifacts and high-resolution with longer acquisition time needs to be considered, especially for application in cerebral MRI.

Magnetic resonance imaging ultrasonography fusion-guided transforaminal epidural steroid injection: a retrospective cohort.

This study aimed to evaluate the applicability and technical feasibility of magnetic resonance imaging (MRI) and ultrasonography (US) fusion-guided transforaminal epidural steroid injection (TFESI) in patients with lumbar disc herniation (LDH) leading to radiculopathy, who are unresponsive to conservative treatment. This retrospective study included 21 patients aged 18-65 years who underwent MRI-US fusion-guided TFESI for LDH-induced radiculopathy. Patient data, including demographic characteristics, body mass index (BMI), fluoroscopy duration, radiation dose, and procedure success, were analyzed. Success was defined by the contrast-spread pattern during the procedure. Statistical analyses were performed to identify factors predicting procedural success. The MRI-US fusion-guided TFESI procedure was successful in 81% of patients. Successful outcomes were significantly associated with younger age (≤ 56 years, p < 0.001), lower BMI (≤ 28kg/m², p < 0.001), shorter fluoroscopy duration (> 4.9s, p < 0.001), and lower radiation dose (> 3.7 mGy, p < 0.001). A positive correlation was observed between age and radiation dose (p = 0.030), as well as between BMI and radiation dose (p = 0.049). MRI-US fusion-guided TFESI is a feasible and safe technique with a high success rate and low radiation exposure in patients with LDH-induced radiculopathy. Younger age, lower BMI, shorter fluoroscopy duration, and lower radiation dose are significant predictors of procedural success. This technique may enhance spatial orientation during the procedure, potentially improving outcomes particularly in younger patients with lower BMI.

UTE MRI technical developments and applications in osteoporosis: a review

Osteoporosis (OP) is a metabolic bone disease that affects more than 10 million people in the USA and leads to over two million fractures every year. The disease results in serious long-term disability and death in a large number of patients. Bone mineral density (BMD) measurement is the current standard in assessing fracture risk; however, the majority of fractures cannot be explained by BMD alone. Bone is a composite material of mineral, organic matrix, and water. While bone mineral provides stiffness and strength, collagen provides ductility and the ability to absorb energy before fracturing, and water provides viscoelasticity and poroelasticity. These bone components are arranged in a complex hierarchical structure. Both material composition and physical structure contribute to the unique strength of bone. The contribution of mineral to bone’s mechanical properties has dominated scientific thinking for decades, partly because collagen and water are inaccessible using X-ray based techniques. Accurate evaluation of bone requires information about its components (mineral, collagen, water) and structure (cortical porosity, trabecular microstructure), which are all important in maintaining the mechanical integrity of bone. Magnetic resonance imaging (MRI) is routinely used to diagnose soft tissue diseases, but bone is “invisible” with clinical MRI due to its short transverse relaxation time. This review article discusses using ultrashort echo time (UTE) sequences to evaluate bone composition and structure. Both morphological and quantitative UTE MRI techniques are introduced. Their applications in osteoporosis are also briefly discussed. These UTE-MRI advancements hold great potential for improving the diagnosis and management of osteoporosis and other metabolic bone diseases by providing a more comprehensive assessment of bone quantity and quality.

Systematic review of functional magnetic resonance imaging (fMRI) applications in the preoperative planning and treatment assessment of brain tumors

Systematic review of functional magnetic resonance imaging (fMRI) applications in the preoperative planning and treatment assessment of brain tumors

Biological and Chemical Assessment of the Liposomes Carrying a Herbal MRI Contrast Agent.

This study investigates the development and characterization of liposomes as carriers for a novel herbal contrast agent for magnetic resonance imaging (MRI). Liposomes were synthesized using phosphatidylcholine and cholesterol for the lipid bilayer membrane and a polar fraction isolated from the "Suaeda" plant for the aqueous phase. The encapsulation efficiency, size, zeta potential, stability, and morphology of the liposomes were evaluated using various techniques. Additionally, by cytotoxicity assays, we contrasted the toxicity of the encapsulated contrast agent to the nonencapsulated form. Finally, relaxivity computations were performed to assess the suitability of the liposomal agent for MRI applications. The liposomal contrast agent had suitable physical properties (stable mean size of 163 nm and zeta potential of -60 mV) and better biochemical characteristics than nonencapsulated media. The liposomal agent demonstrated increased relaxivity and acceptable cytotoxicity with a contrast-making concentration. Therefore, the encapsulated herbal contrast agent can be useful for biological applications.

Ultra-Low-Field Portable Brain Magnetic Resonance Imaging in Patients With Cardiac Devices: Current Evidence and Future Directions.

The use of cardiac devices, including mechanical circulatory support (MCS), cardiac implantable electronic devices (CIEDs), and pacing wires, has increased and significantly improved survival in patients with severe cardiac failure. However, these devices are frequently associated with acute brain injuries (ABIs) including ischemic strokes, intracranial hemorrhages, seizures, and hypoxic-ischemic brain injury which contribute substantially to morbidity and mortality. Computed tomography (CT) and magnetic resonance imaging (MRI), the standard imaging modalities for ABI diagnosis, can pose significant challenges in this patient population due to the risks associated with patient transportation and the incompatibility of ferromagnetic components of certain cardiac devices with high magnetic field of the MRI. This review discusses the application of Ultralow-field portable MRI (ULF-pMRI), which operates at much lower magnetic field (0.064 T), with the potential to allow safe bedside imaging of critically ill patients. In this review, we detail the clinical studies and research findings defining the safety, feasibility, and diagnostic utility of ULF-pMRI in detecting ABI in the critically ill. We further discuss the potential broader applications of ULF-pMRI, as a standard diagnostic tool for neurocritical care in patients with cardiac devices. The integration of such technology into current practice promises to enhance diagnostic accuracy, improve patient outcomes, and optimize healthcare resources.

Observation of Radio-Frequency Mie Resonances in High-Permittivity Dielectric Spheres

Abstract We investigate Mie resonances in a high-permittivity dielectric (ceramic) sphere within the radio-frequency (RF) range, exploring its potential application in magnetic resonance imaging (MRI). Using a transmitting and a receiving RF coil, we observe Mie resonance signatures in both the transmission frequency spectrum and the magnetic field distribution surrounding a 40 mm-diameter sphere. Through full-wave numerical simulations and a standard fitting technique, we identify and characterize the lowest-frequency transverse-electric resonance modes of the sphere at 141.6, 201.4, 259.6, and 282.6 MHz, each exhibiting high-quality factors (300). Remarkably, we experimentally map the magnetic field distributions corresponding to each Mie resonance. Our results provide valuable insights for developing innovative approaches to manipulate RF waves, particularly by shaping and controlling the near-field outside the dielectric resonator through Mie resonances, an area largely unexplored in MRI technology.

Microwave-assisted synthesis of dual responsive luminomagnetic rare earth metal ions (Nd3+, Dy3+) co-doped nanohydroxyapatite for biomedical applications.

The existing demand for the development of innovative multimodal imaging nanomaterial probes for biomedical applications stems from their unique combination of dual response modalities, i.e., photoluminescence (PL) and magnetic resonance imaging (MRI). In this study, for the first time, neodymium (Nd3+) and dysprosium (Dy3+) rare earth (RE) metal ions were co-doped into a hydroxyapatite (HAp) crystal lattice using a simple microwave-assisted synthesis technique to incorporate the essential properties of both the lanthanides in HAp. Theoretical as well as experimental studies were performed on novel Nd:Dy:HAp nanoparticles (NPs) to understand their photoluminescence and magnetic behaviour. Through co-precipitation, RE (Nd3+, Dy3+) ions were effectively integrated into the HAp crystal lattice, where they preferentially occupied the calcium ion (Ca2+) sites. The as-synthesized HAp, Nd:HAp, Dy:HAp, and Nd:Dy:HAp samples were characterized using different analytical tools. The PL and magnetic characteristics of Nd:Dy:HAp were dependent on the RE dopant ion type and concentration. In comparison with the pure HAp, the RE co-doped (Nd:Dy:HAp) NPs displayed multimodal features due to efficient energy transfer from the Nd3+ (sensitizer) to the Dy3+ (activator) ions. Furthermore, Nd:Dy:HAp NPs had good antimicrobial properties and they also displayed low cell toxicity effects. Hence, Nd:Dy:HAp NPs are attractive biomaterials for PL and MRI applications (e.g. permanent bone and tooth implants) and they can effectively be utilized in the biomedical industry for target-specific drug delivery, bioimaging, functional antimicrobial coatings etc. due to their tunable PL, magnetic, antimicrobial, and biocompatible capabilities.

Amphoteric β-cyclodextrin coated iron oxide magnetic nanoparticles: new insights into synthesis and application in MRI.

This work presents a group of high-quality hydrophilic and negatively charged coated, iron oxide magnetic nanoparticles (MNPs) that have been prepared using a microwave-ultrasound-assisted protocol, and demonstrates the great impact that the synthetic strategy has on the resulting MNPs. The different coatings tested, including citric acid, carboxymethyl dextran and β-cyclodextrin (βCD)/citric acid have been compared and have shown good dispersibility and stability. The ability of βCD to maintain the inclusive properties of the coated MNPs has been proven as well as their cytocompatibility. An amino citrate-modified βCD is proposed and its capabilities as a flexible amphoteric adsorbing device have been studied. The NMR relaxometric properties of the coated MNPs have been investigated using field-cycling nuclear magnetic relaxation dispersion profiles. For the amino citrate-modified βCD system, the order of magnitude of the Néel relaxation time is in the typical range for superparamagnetic systems' reversal times, i.e., 10-10-10-7 s. The r d value corresponds to the physical radius of the magnetic core, suggesting that, in this particular case, the coating does not prevent the diffusive motion of water molecules, which provide the basis for potential future magnetic resonance imaging (MRI) applications.

Systematic analysis and application of magnetic resonance imaging

Systematic analysis and application of magnetic resonance imaging

MR‐imaging biomarkers for eye tumors

In the clinical care for eye tumor patients, more and more applications of magnetic resonance imaging (MRI) have emerged in the last years. In retinoblastoma, for example, it is routinely used to screen for tumor invasion in the optic nerve. In uveal melanoma, the most frequently occurring primary intraocular malignancy in adults, MRI's three‐dimensional visualization of the tumor and surrounding structures give it an increasingly prominent place in radiotherapy planning. As a result of these clinical applications, functional MRI‐parameters, which are often obtained in the same scan session, gain in relevance. These functional sequences non‐invasively obtain tumor biomarkers that can be used for differential diagnosis, prognosis and response assessment. In this lecture we will cover the most important MR‐biomarkers, explain the underlying biology they probe, and highlight their clinical and scientific applications.We will start with perfusion‐weighted MRI (PWI), a technique that obtains information on the tumor perfusion by administering an intravenous contrast agent while continuously imaging the eye. In addition to explaining the various pharmacokinetic models to quantitatively assess these data, we will show how, the clinically more feasible, semi‐quantitative assessment can already be used for differential diagnosis and early assessment of treatment response. Subsequently, we will discuss diffusion weighted imaging (DWI), a biomarker of the lesion's cellularity. Although it is a powerful biomarker to discriminate between benign and malignant lesions, its clinical value for prognosis and treatment response are still debated. We will end with a few clinical cases that demonstrate how these and other MR‐biomarkers complement the conventional ophthalmic imaging.

Controle de qualidade de produtos agrícolas através de sensores de Ressonância Magnética

ABSTRACT Nuclear magnetic resonance (NMR) is a spectroscopy technique widely used by chemists and physicists to determine the chemical structure of molecules that was adapted to generate imaging, known as nuclear magnetic resonance imaging (MRI), which is widely used in medical diagnosis. The importance of NMR in chemistry, physics, medicine, materials, and agriculture has been recognized with several Nobel Prizes in Physics, 1952, Chemistry, 1991 and 2002, and Medicine in 2003. Therefore, NMR can be applied to obtain: i) imaging of the human body, animal and materials; ii) high-resolution spectra to obtain structural and dynamical information of chemicals, materials etc.; and iii) quantitative and qualitative information of chemical composition of products such as food and agricultural products, using low-resolution relaxometry. High-resolution NMR and MRI have been applied in agri-food products, mostly as a research tool as they typically rely on expensive and bulk instruments, which restrict their uses in routine applications. The NMR sensors that have been more frequently used in agri-food products are based on low-resolution or low-field or time-domain NMR (TD-NMR) instruments. These low-cost instruments have been used for qualitative and quantitative analysis of agri-food products such as intact seeds and grains, intact fruits, meat, oils, and processed foods. In this paper, an overview of the NMR techniques and its main instrumentation aspects are presented, and some applications of TD-NMR and MRI in the non-invasive analysis of food, seeds, and others agricultural products are discussed.

Automatic Adaptive Algorithm for Delineation of Cerebral-Spinal Fluid Regions for Non-contrast Magnetic Resonance Imaging Volumetry and Cisternography in Mice.

Magnetic resonance imaging (MRI) is an invaluable method of choice for anatomical and functional in vivo imaging of the brain. Still, accurate delineation of the brain structures remains a crucial task of MR image evaluation. This study presents a novel analytical algorithm developed in MATLAB for the automatic segmentation of cerebrospinal fluid (CSF) spaces in preclinical non-contrast MR images of the mouse brain. The algorithm employs adaptive thresholding and region growing to accurately and repeatably delineate CSF space regions in 3D constructive interference steady-state (3D-CISS) images acquired using a 9.4 Tesla MR system and a cryogenically cooled transmit/receive resonator. Key steps include computing a bounding box enclosing the brain parenchyma in three dimensions, applying an adaptive intensity threshold, and refining CSF regions independently in sagittal, axial, and coronal planes. In its original application, the algorithm provided objective and repeatable delineation of CSF regions in 3D-CISS images of sub-optimal signal-to-noise ratio, acquired with (33 μm)3 isometric voxel dimensions. It allowed revealing subtle differences in CSF volumes between aquaporin-4-null and wild-type littermate mice, showing robustness and reliability. Despite the increasing use of artificial neural networks in image analysis, this analytical approach provides robustness, especially when the dataset is insufficiently small and limited for training the network. By adjusting parameters, the algorithm is flexible for application in segmenting other types of anatomical structures or other types of 3D images. This automated method significantly reduces the time and effort compared to manual segmentation and offers higher repeatability, making it a valuable tool for preclinical and potentially clinical MRI applications. Key features • This protocol presents a fully automatic adaptive algorithm for the delineation of CSF space regions in 3D-CISS in vivo images of the mouse brain. • The algorithm represents an analytical method for adaptive CSF regions separation based on cumulative distribution of brain image intensities and contrast calculation-based slice-wise region growing. • Users can interactively alter the input parameters to modify the algorithm's output in a variety of 3D brain MR and μCT or CT images. • The algorithm is implemented in MATLAB 2021a and is compatible with all versions up to 2024a.

Transcranial Direct Current Stimulation Over Bilateral Temporal Lobes Modulates Hippocampal-Occipital Functional Connectivity and Visual Short-Term Memory Precision.

Although the medial temporal lobe (MTL) is traditionally considered a region dedicated to long-term memory, recent neuroimaging and intracranial recording evidence suggests that the MTL also contributes to certain aspects of visual short-term memory (VSTM), such as the quality or precision of retained VSTM content. This study aims to further investigate the MTL's role in VSTM precision through the application of transcranial direct current stimulation (tDCS) and functional magnetic resonance imaging (fMRI). Participants underwent 1.5 mA offline tDCS over bilateral temporal lobes using left cathodal and right anodal electrodes, administered for either 20 min (active) or 0.5 min within a 20-min window (sham), in a counterbalanced design. As the electrical current passes through midbrain structures with this bilateral stimulation montage, prior behavioral and modeling evidence suggests that this tDCS protocol can modulate MTL functions. To confirm this and examine its impacts on VSTM, participants completed a VSTM color recall task immediately following tDCS, while undergoing a 20-min fMRI scan and a subsequent 7.5-min resting-state scan, during which they focused on a fixation cross. Behavioral results indicated that this tDCS protocol decreased VSTM precision without significantly affecting overall recall success. Furthermore, psychophysiological interaction analysis revealed that tDCS over the temporal lobe modulated hippocampal-occipital functional connectivity during the VSTM task, despite no main effect on fMRI BOLD activity. Notably, this modulation was also observed during resting-state fMRI 15-20 min post-tDCS, with the magnitude of the effect correlating with participants' behavioral changes in VSTM precision across active and control conditions. Combined, these findings suggest that tDCS over the temporal lobe can modulate the intrinsic functional connectivity between the MTL and visual sensory areas, thereby affecting VSTM precision.

Dental Magnetic Resonance Imaging: Practical insights and evaluation of benefits and drawbacks in dentistry and oral and maxillofacial surgery

Dental magnetic resonance imaging (MRI) has long been perceived as overly complex, costly, and limited in availability. Despite the numerous advantages of this radiation-free, non-invasive procedure for soft tissue diagnostics in the head and neck region, its imaging capabilities for hard tissue, such as bones and teeth, have thus far remained limited in comparison to conventional X-ray technology. In recent years, however, technological advances have led to a notable enhancement in the image quality and the range of applications of dental MRI. This article presents a comprehensive review of the current literature on the utilization of dental MRI for dentomaxillofacial conditions. The article focusses on novel MRI protocols that have been specifically developed to address the inherent challenges associated with imaging the head and neck region. It also considers the latest technological advances, including innovative coils and the use of low and high-field MR systems. The practical case studies are from the fields of conservative dentistry, prosthodontics, orthodontics, oral surgery, and maxillofacial surgery, demonstrating the theoretical concepts and emphasizing the clinical advantages of dental MRI. In conclusion, dental MRI can be a valuable complement to and, in certain cases, a true alternative to X-ray-based procedures.

Application of functional magnetic resonance imaging in diagnosing blast-related traumatic brain injuries

Application of functional magnetic resonance imaging in diagnosing blast-related traumatic brain injuries

The Influence of Cyanine 5.5 and Doxorubicin on Cell Cycle Arrest, Magnetic Resonance, and Near-Infrared Fluorescence Optical Imaging for Fe3O4-Encapsulated PLA-TPGS Nanoparticles.

The combination of magnetic resonance imaging (MRI)/near-infrared (NIR) fluorescence signals and chemotherapy agents has been developed for cancer diagnosis and treatment. In this work, we investigated the impacts of Cyanine 5.5 and Doxorubicin on cell cycle arrest, magnetic resonance, and NIR fluorescence optical imaging for Fe3O4-encapsulated nanosystems based on poly(lactide)-tocopheryl polyethylene glycol succinate (PLA-TPGS) copolymer. Although Cyanine 5.5 and Fe3O4 nanoparticles (NPs) are less cytotoxic than Doxorubicin, they present a cytostatic effect, inducing cell cycle arrest at the G2/M phase in human brain adenocarcinoma (CCF-STTG1) cells. For MRI applications, the permeability of the PLA-TPGS copolymer coating layer to water molecules might lengthen the translational diffusion time ( ), causing the higher relaxivity ratio (r2/r1) compared to bare Fe3O4 NPs under an applied magnetic field (7 Tesla). Notably, the chemical structures of Cyanine 5.5 and Doxorubicin significantly contribute to the enhancement of the T2 relaxivities of Fe3O4 NPs through π-π and ρ-π conjugation. Furthermore, the radiance ratio and signal-to-noise ratio enhancement and a slight blue shift in the optimal excitation and emission wavelengths were recorded. These findings show the potential for in vivo MRI and NIR bioimaging experiments of the nanoparticles.

Assessment of four-dimensional flow MRI for prediction of varices risk in cirrhotic patients.

This study aims to validate the application of abdominal four-dimensional flow magnetic resonance imaging (MRI) for cirrhotic patients and quantify its effectiveness in assessing the hemodynamic impacts of cirrhosis to evaluate varices. All consecutive patients who underwent MRIs between September 2022 and June 2023 were enrolled. Groups were divided into varicose, non-varicose, and healthy groups. ANOVA and post hoc LSD-t tests were used for statistical analysis. The correlation between hemodynamic parameters and liver function grade was evaluated using Kendall's correlation coefficient. A total of 80 patients were included (53 cirrhotic, 27 healthy). Significant disparities were found in main portal vein flow (MPV-FR), splenic vein flow (SV-FR), and vessel diameters (MPV-VD, SV-VD) among the groups (p < 0.05). MPV-FR was higher in the varicose group (24.81 ± 8.52) compared to non-varicose (19.52 ± 5.07) and healthy groups (17.26 ± 5.48). The most robust assessment of variceal risk was achieved by combining the flow rates (FRs) and VDs of MPV and SV (AUC 0.83, 95% CI 0.72-0.94). The combined indices of FRs and VDs of MPV and SV effectively predict the occurrence of varicose veins in cirrhotic patients. Question Non-invasive prediction of variceal risk is essential for the clinical management of advanced chronic cirrhosis, yet existing clinical examinations are inadequate. Findings The effective assessment of variceal risk was achieved by combining the flow rates and vessel diameters of the main portal vein and splenic vein. Clinical relevance Four-dimensional flow MRI can reveal hemodynamic changes in cirrhotic patients and assist in identifying gastroesophageal varices, serving as a marker for varices risk prediction.

Fetal Cardiovascular Magnetic Resonance: History, Current Status, and Future Directions.

Fetal cardiovascular magnetic resonance imaging (MRI) has emerged as a complementary modality for prenatal imaging in suspected congenital heart disease. Ongoing technical improvements extend the potential clinical value of fetal cardiovascular MRI. Ascertaining equivocal prenatal diagnostics obtained with ultrasonography allows for appropriate parental counseling and planning of postnatal surgery. This work summarizes current acquisition techniques and clinical applications of fetal cardiovascular MRI in the prenatal diagnosis and follow-up of fetuses with congenital heart disease. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 3.

Engineering amphiphilic alkenyl lipids for self-assembly in functional hybrid nanostructures

The development of biocompatible hybrid nanosystems for advanced functional applications presents significant challenges to the research community. Key obstacles include the poor solubility of these nanosystems in water and the difficulty of precisely controlling their nanostructure dimensions and composition. A promising approach to overcoming these challenges is the self-assembly of surfactant-based building blocks into well-ordered hybrid nanostructures. In this study, we explore the relationship between structure and self-assembly in novel low molecular weight amphiphilic molecules to produce stable and biocompatible hybrid nanostructures. We investigated the self-assembly behavior of two families of amphiphiles derived from alkenyl lipids with one or two double bonds, leading to distinct hybrid supramolecular structures facilitated by the incorporation of hydrophobic iron oxide nanoparticles (IONPs) as templates. The presence of double bonds in the lipid tail and the morphology of the amphiphile influence the arrangement on the hydrophobic NPs. Amphiphiles with a single double bond in the lipid tail form highly water-soluble, well-ordered micellar-like structures on the IONP surfaces, while those with two double bonds create disordered lipid nanoparticles. Furthermore, these amphiphilic molecules can self-organize into higher-order hybrid supramolecular structures, such as vesicles, with potential applications in magnetic resonance imaging (MRI).