Magnetic Resonance Imaging Contrast Research Articles

Micelles as nanocarriers of fluorescent and magnetic dendrimers for potential bimodal imaging applications

Bimodal magnetic-fluorescent materials that integrate magnetic and fluorescent properties have attracted significant attention due to their potential applications in biomedical imaging, biosensing, and therapeutic diagnosis. Tetra-amido-TEMPO 1, a compound that combines a fluorescent oligo(styryl)benzene dendrimer core with TEMPO radicals in its four branches was synthesized and used to form micelles with CTAB in water. DLS and Cryo-TEM techniques revealed the formation of micelles exhibiting a narrow particle size distribution, with an average hydrodynamic diameter ranging from 95 to 140 nm. After micellization, the ultraviolet-visible absorption and fluorescence emission intensities of micelles increased with tetra-amido-TEMPO concentration and EPR spectroscopy demonstrated consistent three-line spectra in the micelles, with the integrated area directly proportional to the amount of tetra-amido-TEMPO present. Besides, sufficient contrast enhancement in the proton T1 relaxation time-weighted magnetic resonance images in vitro proved their ability to act as magnetic resonance imaging (MRI) contrast agents. These tetra-amido-TEMPO/CTAB micelles offer an aqueous-compatible system for this bimodal fluorescent-magnetic molecule, showcasing proof of concept of their potential for biomedical applications.

Synergistic response of PEG coated manganese dioxide nanoparticles conjugated with doxorubicin for breast cancer treatment and MRI application

In this research work, we designed a smart biodegradable PEG-coated MnO2 nanoparticles conjugated with doxorubicin (PMnO2-Dox NPs) for dual chemo-photodynamic therapy and magnetic resonance imaging (MRI) application. This highly sensitive pH-responsive PMnO2-Dox NPs causes effective drug release under acidic pH environment. PMnO2-Dox NPs not only improves the efficacy of chemo-photodynamic therapy due to synergistic response as well as improved MRI imaging via boosting T1 MRI contrast. Manifold characterization techniques have been employed for materials investigation. Crystallography of PMnO2-Dox NPs were performed by using XRD analysis, which confirmed tetragonal crystal structure with an approximate crystallite size of 20–30 nm. Surface morphology was confirmed via SEM analysis, results indicated the spherical and asymmetric agglomerated nanocluster of PMnO2-Dox NPs. In in vitro bioassay, the anticancer activity of PMnO2-Dox NPs were tested against breast cancer (MCF-7) cell line using MTT test. Moreover, it can also inhibit the growth of primary and secondary cancers without light exposure. Results suggested that PMnO2-Dox NPs not only convenient for cancer treatment via combined chemo-photodynamic therapy but also address the way towards a comprehensive strategy for MRI application via bright contrast agent T1 after overcoming the problem of multidrug resistance (MDR) and synergistic response of therapeutic analysis.

Confounded Magnetic Resonance Imaging Contrast Agent Exposures and Gadolinium Retention in Organs

Confounded Magnetic Resonance Imaging Contrast Agent Exposures and Gadolinium Retention in Organs

Relaxivity Modulation of Gd-HPDO3A-like Complexes by Introducing Polar and Protic Peripheral Groups

In the last three decades, high-relaxivity Magnetic Resonance Imaging (MRI) contrast agents (CAs) have been intensively sought, aiming at a reduction in the clinically injected dose while maintaining the safety of the CA and obtaining the same pathological information. Thus, four new Gd(III) complexes based on modified 10-(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (HP-DO3A) macrocyclic structure were designed and synthesized by introducing further polar and protic functional groups (amides, phosphonates, and diols) adjacent to the metal-coordinated hydroxyl group. A detailed 1H NMR relaxometric analysis allowed us to investigate the effect of these functional groups on the relaxivity, which showed a 20–60% increase (at 0.5 T, 298 K, and pH 7.4) with respect to that of clinically approved CAs. The contribution of the water molecules H-bonded to these peripheral functional groups on the relaxivity was evaluated in terms of the second sphere effect or prototropic exchange of labile protons.

Advances in molecular imaging for early detection of lung cancer

Lung cancer remains the second most commonly diagnosed cancer globally and the leading cause of cancer-related deaths, a trend consistent in the United States as of 2023. One of the key reasons for the high mortality rate of lung cancer is its poor prognosis, with 75% of patients diagnosed at middle and advanced stages. Early detection of subclinical lung cancer, metastases, and their fibrotic stroma is crucial for enabling timely treatment, reducing reoccurrence, and stratifying patients. Current diagnostic methods, such as lung biopsy for patients with small nodules, are highly invasive and technically challenging. The radiological gold standard, computed tomography (CT), is associated with ionizing radiation. However, positron emission tomography (PET) and magnetic resonance imaging (MRI) have emerged as promising methodologies for lung cancer diagnosis. PET tracers with a variety of targeting mechanisms are currently under development in human trials. With advancements in hardware and software over the past decades, radiation-free MRI has been clinically and preclinically validated as an alternative to CT. Moreover, novel-targeted MRI contrast agents have been tested in animal models and show strong translational potential. In this review, we summarize the state-of-the-art progress in molecular imaging for the early detection of lung cancer and its potential biomarkers.

Optimized gadolinium-DO3A loading in RAFT-polymerized copolymers for superior MR imaging of aging blood-brain barrier.

The development of gadolinium-based contrast agents (GBCAs) has been pivotal in advancing magnetic resonance imaging (MRI), offering enhanced soft tissue contrast without ionizing radiation exposure. Despite their widespread clinical use, the need for improved GBCAs has led to innovations in ligand chemistry and polymer science. We report a novel approach using methacrylate-functionalized DO3A ligands to synthesize a series of copolymers through direct reversible addition-fragmentation chain transfer (RAFT) polymerization. This technique enables precise control over the gadolinium content within the polymers, circumventing the need for subsequent conjugation and purification steps, and facilitates the addition of other components such as targeting ligands. The resulting copolymers were analysed for their relaxivity properties, indicating that specific gadolinium-DO3A loading contents between 12-30 mole percent yield optimal MRI contrast enhancement. Inductively coupled plasma (ICP) measurements corroborated these findings, revealing a non-linear relationship between gadolinium content and relaxivity. Optimized copolymers were synthesized with the claudin-1 targeting peptide, C1C2, to image BBB targeting in aged mice to show imaging utility. This study presents a promising pathway for the development of more efficient GBCA addition to copolymers for targeted drug delivery and bioimaging application.

Theranostics: aptamer-assisted carbon nanotubes as MRI contrast and photothermal agent for breast cancer therapy

Breast cancer is one of the leading causes of death among women globally, making its diagnosis and treatment challenging. The use of nanotechnology for cancer diagnosis and treatment is an emerging area of research. To address this issue, multiwalled carbon nanotubes (MWCNTs) were ligand exchanged with butyric acid (BA) to gain hydrophilic character. The successful functionalization was confirmed by FTIR spectroscopy. Surface morphology changes were observed using SEM, while TEM confirmed the structural integrity of the MWCNTs after functionalization. Particle size, zeta potential, and UV spectroscopy were also performed to further characterize the nanoparticles. The breast cancer aptamer specific to Mucin-1 (MUC-1) was then conjugated with the functionalized MWCNTs. These MWCNTs successfully targeted breast cancer cells (MDA-MB-231) as examined by cellular uptake studies and exhibited a reduction in cancer-induced inflammation, as evidenced by gene transcription (qPCR) and protein expression (immunoblotting) levels. Immunoblot and confocal-based immunofluorescence assay (IFA) indicated the ability of CNTs to induce photothermal cell death of MDA-MB-231 cells. Upon imaging, cancer cells were effectively visualized due to the MWCNTs’ ability to act as magnetic resonance imaging (MRI) contrast agents. Additionally, MWCNTs demonstrated photothermal capabilities to eliminate bound cancer cells. Collectively, our findings pave the way for developing aptamer-labeled MWCNTs as viable “theranostic alternatives” for breast cancer treatment.Graphical abstract

Bifunctional Bismuth-Based Layered Double Hydroxide Sonosensitizer for Magnetic Resonance Imaging-Guided Sonodynamic Cancer Therapy.

Novel inorganic sonosensitizers with excellent reactive oxygen species (ROS) generation activity and multifunctionality are appealing in sonodynamic therapy (SDT). Herein, amorphous bismuth (Bi)-doped CoFe-layered double hydroxide (a-CoBiFe-LDH) nanosheets are proposed via crystalline-to-amorphous phase transformation strategy as a new type of bifunctional sonosensitizer, which allows ultrasound (US) to trigger ROS generation for magnetic resonance imaging (MRI)-guided SDT. Importantly, a-CoBiFe-LDH nanosheets exhibit much higher ROS generation activity (≈6.9 times) than that of traditional TiO2 sonosensitizer under US irradiation, which can be attributed to the acid etching-induced narrow band gap, high electron (e-)/hole (h+) separation efficiency and inhibited e-/h+ recombination. In addition, the paramagnetic properties of Fe ion endow a-CoBiFe-LDH with excellent MRI contrast ability, making it a promising contrast agent for T2-weighted MRI. After modification with polyethylene glycol, a-CoBiFe-LDH nanosheets can function as a high-efficiency sonosensitizer to activate p53, MAPK, oxidative phosphorylation, and apoptosis-related signaling pathways, ultimately inducing cell apoptosis in vitro and tumor ablation in vivo under US irradiation, which shows great potential for clinical cancer treatment.

Contrast of muscle magnetic resonance imaging and pathological findings of muscle tissue in patients with anti-aminoacyl transfer RNA synthetase antibodies.

Methods: Patients with idiopathic inflammatory myopathies (IIMs) diagnosed using the 2017 EULAR/ACR classification criteria in our university between 2005 and 2020 were retrospectively reviewed. IIMs were subclassified into the anti-ARS syndrome (ASSD), immune-mediated necrotizing myositis (IMNM), Dermatomyositis DM and others. Fat-suppressed T2-weighted MRI and muscle biopsy specimens were assessed in IIMs followed by the comparison among the four subgroups. MRI findings were available for 62 patients and histopathological findings were available for 27 patients. Perifascicular atrophy or necrosis in the muscle tissues from the patients with IIM was more frequently observed in patients with subcutaneous and fascial high signal intensity (HSI) on MRI than those without. Four-group comparison among ASSD, IMNM, DM and others revealed HSI in fasciae on MRI was more frequently observed in patients with ASSD and DM than others. Perifascicular atrophy or necrosis in muscle tissues was more frequently observed in patients with ASSD than in others. Patients with ASSD had distinct MRI features compared with anti-ARS negative patients. The fascial high signal intensity on MRI may reflect distinctive pathological features of muscles.

Twinned neuroimaging analysis contributes to improving the classification of young people with autism spectrum disorder

Autism spectrum disorder (ASD) is diagnosed using comprehensive behavioral information. Neuroimaging offers additional information but lacks clinical utility for diagnosis. This study investigates whether multi-forms of magnetic resonance imaging (MRI) contrast can be used individually and in combination to produce a categorical classification of young individuals with ASD. MRI data were accessed from the Autism Brain Imaging Data Exchange (ABIDE). Young participants (ages 2–30) were selected, and two group cohorts consisted of 702 participants: 351 ASD and 351 controls. Image-based classification was performed using one-channel and two-channel inputs to 3D-DenseNet deep learning networks. The models were trained and tested using tenfold cross-validation. Two-channel models were twinned with combinations of structural MRI (sMRI) maps and amplitude of low-frequency fluctuations (ALFF) or fractional ALFF (fALFF) maps from resting-state functional MRI (rs-fMRI). All models produced classification accuracy that exceeded 65.1%. The two-channel ALFF-sMRI model achieved the highest mean accuracy of 76.9% ± 2.34. The one-channel ALFF-based model alone had mean accuracy of 72% ± 3.1. This study leveraged the ABIDE dataset to produce ASD classification results that are comparable and/or exceed literature values. The deep learning approach was conducive to diverse neuroimaging inputs. Findings reveal that the ALFF-sMRI two-channel model outperformed all others.

Synergistic Enhancement of Diagnostic Imaging: Synthesis and Preliminary Safety Evaluation of Gadolinium-Doped Carbon Quantum Dots as Dual-Contrast Agent.

The present study explores the synthesis and bio-safety evaluation of gadolinium-doped carbon quantum dots (GCQDs) as a potential dual-contrast agent for diagnostic imaging. GCQDs exhibit both fluorescent and magnetic properties, making them suitable for UV-Vis and magnetic resonance imaging (MRI). The synthesis of GCQDs was achieved via hydrothermal treatment, incorporating gadolinium into the carbon quantum dot matrix. The magnetic properties of GCQDs were analyzed, showing significantly enhanced values compared to gadobutrol, a common MRI contrast agent. However, synthesis constraints limit the gadolinium content achievable in nanodots. To assess the safety of GCQDs, their effects on the embryonic development of zebrafish (Danio rerio) were examined. Various concentrations of GCQDs were tested, observing mortality rates, hatchability, malformations, heartbeats, spontaneous movement, and GCQDs uptake. Dialysis studies indicated that gadolinium ions are incorporated into the internal structure of the carbon nanodots. Zebrafish toxicity tests revealed that while survival rates were comparable to control groups, hatchability decreased significantly with higher gadolinium concentrations in GCQDs. Fluorescence microscopy showed no statistical differences in the fluorescence intensity between groups. These findings suggest that GCQDs could serve as an effective dual-contrast agent, combining the optical imaging capabilities of CQDs with the enhanced MRI contrast provided by gadolinium. This study underscores the need for further research on the synthesis methods and biological interactions of GCQDs to ensure their safety and efficacy in medical applications.

Rational Design of Mono-Substituted Gd-DOTA as Highly Stable and Efficient MRI Contrast Agents for Hepatobiliary and Inflammation Imaging.

Hepatobiliary-specific magnetic resonance imaging contrast agents (MRI CAs) play a crucial role in the early diagnosis of hepatocellular carcinoma (HCC). However, only two acyclic CAs, Gd-BOPTA and Gd-EOB-DTPA, exhibit unfavorable kinetic inertness. Our study focused on the development of superior stable innovative macrocyclic CAs. By introducing a lipophilic benzyloxy group (OBn) into the H4DOTA ring (Gd-L1), we achieved significant enhancement in kinetic inertness. In vivo experiments in mice demonstrated that 40% of the dosage was distributed to the liver at 5 min, providing sustained hepatic enhancement for over 35 min. We also developed an MPO-responsive MRI CA (Gd-L3), which can participate in the "peroxidase cycle" as the substrate, generating oligomers with a 3.8-fold increase in relaxivity, and selectively enhance the lesion in an acute gout mouse model. Overall, our work represents a significant advancement in the field of hepatic and inflammatory MRI, offering promising avenues for early diagnosis and improved imaging outcomes.

Imaging arterial and venous vessels using Iron Dextran enhanced multi-echo 3D gradient echo MRI at 7T.

Iron Dextran is a widely used iron oxide compound to treat iron-deficiency anemia patients in the clinic. Similar to other iron oxide compounds such as Ferumoxytol, it can also be used off-label as an intravascular magnetic resonance imaging (MRI) contrast agent due to its strong iron-induced T2 and T2* shortening effects. In this study, we seek to evaluate the feasibility of using Iron Dextran enhanced multi-echo susceptibility weighted imaging (SWI) MRI at 7T to image arterial and venous blood vessels in the human brain. Phantom experiments were performed to measure the r2* relaxivity for Iron Dextran in blood, based on which the SWI sequence was optimized. Pre- and post-infusion MR images were acquired in human subjects from which maps of arteries and veins were extracted. The post-contrast SWI images showed enhanced susceptibility difference between blood and the surrounding tissue in both arteries and veins. Our results showed that the proposed Iron Dextran enhanced multi-echo SWI approach allowed the visualization of blood vessels with diameters down to ~100 μm, including small blood vessels supplying and draining small brain structures such as the hippocampus. We conclude that Iron Dextran can be an alternative iron-based MRI contrast agent for blood vessel imaging in the human brain.

Fe2+-Dominated Relaxometric Properties of Iron Oxide Nanoparticles as MRI Contrast Agents.

Iron oxide nanoparticles (IONPs) have garnered significant interest as magnetic resonance imaging (MRI) contrast agents due to their exceptional magnetic properties and biocompatibility. Toward more precise diagnosis of diseases, the relaxometric properties of IONPs have become a key research focus. Despite extensive studies on structural factors such as size, morphology, surface modification, crystalline phase, and aggregation state, the correlation between the intrinsic structure and relaxometric behavior remains unclear, particularly for ultrasmall IONPs. To address this issue, we carefully compared IONPs with identical size, shape, and surface modification and found out strong correlations among the content of Fe2+ ions, oxygen vacancies, and the relaxometric properties. By optimizing the reaction system, ultrasmall IONPs showing outstanding relaxometric performance, with longitudinal relaxivity up to 9.0 mM-1 s-1 and transverse relaxivity up to 28.5 mM-1 s-1, were successfully obtained. These results underscore the pivotal role of Fe2+ in the relaxometric properties of IONP-based MRI contrast agents.

Trapped in Endosome PEGylated Ultra-Small Iron Oxide Nanoparticles Enable Extraordinarily High MR Imaging Contrast for Hepatocellular Carcinomas.

The early diagnosis of hepatocellular carcinomas (HCCs) remains challenging in the clinic. Primovist-enhanced magnetic resonance imaging (MRI) aids HCC diagnosis but loses sensitivity for tumors <2cm. Therefore, developing advanced MRI contrast agents is imperative for improving the diagnostic accuracy of HCCs in very-early-stage. To address this challenge, PEGylated ultra-small iron oxide nanoparticles (PUSIONPs) are synthesized and employed as liver-specific T1 MRI contrast agents. Intravenous delivery produces simultaneous hyperintense HCC and hypointense hepatic parenchyma signals on T1 imaging, creating an extraordinarily high tumor-to-liver contrast. Systematic studies uncover PUSIONP distribution in hepatic parenchyma, HCC lesions at the organ, tissue, cellular, and subcellular levels, revealing endosomal confinement of PUSIONP without aggregation. By mimicking such situations, the dependency of relaxometric properties on local PUSIONP concentration is investigated, emphasizing the key role of different endosomal concentrations in liver and tumor cells for high tumor-to-liver contrast and clear tumor boundaries. These findings offer exceptional imaging capabilities for early HCC diagnosis, potentially benefiting real HCC patients.

Impact of the Novel MRI Contrast Agent Gadopiclenol on Radiotherapy Decision Making in Patients With Brain Metastases.

The aim of this study was to assess the effect of gadopiclenol versus gadobenate dimeglumine contrast-enhanced magnetic resonance imaging (MRI) on decision-making between whole-brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS) for treatment of brain metastases (BMs). Patients with BMs underwent 2 separate MRI examinations in a double-blind crossover phase IIb comparative study between the MRI contrast agents gadopiclenol and gadobenate dimeglumine, both administered at 0.1 mmol/kg. The imaging data of a single site using identical MRI scanners and protocols were included in this post hoc analysis. Patients with 1 or more BMs in any of both MRIs were subjected to target volume delineation for treatment planning. Two radiation oncologists contoured all visible lesions and decided upon SRS or WBRT, according to the number of metastases. For each patient, SRS or WBRT treatment plans were calculated for both MRIs, considering the gross target volume (GTV) as the contrast-enhancing aspects of the tumor. Mean GTVs and volume of healthy brain exposed to 12 Gy (V12), as well as Dice similarity coefficient scores, were obtained. The Spearman rank (ρ) correlation was additionally calculated for assessing linear differences. Three different expert radiation oncologists blindly rated the contrast enhancement for contouring purposes. Thirteen adult patients were included. Gadopiclenol depicted additional BM as compared with gadobenate dimeglumine in 7 patients (54%). Of a total of 63 identified metastatic lesions in both MRI sets, 3 subgroups could be defined: A, 48 (24 pairs) detected equal GTVs visible in both modalities; B, 13 GTVs only visible in the gadopiclenol set (mean ± SD, 0.16 ± 0.37 cm3); and C, 2 GTVs only visible in the gadobenate dimeglumine set (mean ± SD, 0.01 ± 0.01). Treatment indication was changed for 2 (15%) patients, 1 from no treatment to SRS and for 1 from SRS to WBRT. The mean GTVs and brain V12 were comparable between both agents (P = 0.694, P = 0.974). The mean Dice similarity coefficient was 0.70 ± 0.14 (ρ = 0.82). According to the readers, target volume definition was improved in 63.9% of cases (23 of 36 evaluations) with gadopiclenol and 22.2% with gadobenate dimeglumine (8 of 36), whereas equivalence was obtained in 13.9% (5 of 36). Gadopiclenol-enhanced MRI improved BM detection and characterization, with a direct impact on radiotherapy treatment decision between WBRT and SRS. Additionally, a more exact target delineation and planning could be performed with gadopiclenol. A prospective evaluation in a larger cohort of patients is required to confirm these findings.

A prospective randomized controlled study of multi-intravenous infusion of umbilical cord mesenchymal stem cells in patients with heart failure and reduced ejection fraction (PRIME-HFrEF) trial: Rationale and design

Background and objectiveThe use of mesenchymal stem cells for heart failure treatment has gained increasing interest. However, most studies have relied on a single injection approach, with no research yet confirming the effects of multiple administrations. The present trial aims to investigate the safety and efficacy of multi-intravenous infusion of umbilical cord-mesenchymal stem cells (UC-MSCs) in patients with heart failure and reduced ejection fraction (HFrEF). MethodsThe PRIME-HFrEF trial is a single-center, prospective, randomized, triple-blinded, placebo-controlled trial of multi-intravenous infusion of UC-MSCs in HFrEF patients. A total of 40 patients meeting the inclusion criteria for HFrEF were enrolled and randomized 1:1 to the MSC group or the placebo group. Patients enrolled will receive intravenous injections of either UC-MSCs or placebo every 6 weeks for three times. Both groups will be followed up for 12 months. The primary safety endpoint is the incidence of serious adverse events. The primary efficacy endpoint is a change in left ventricular ejection fraction (LVEF) measured by left ventricular opacification (LVO) with contrast echocardiography and magnetic resonance imaging (MRI) at 12 months. The secondary endpoints include a composite of the incidence of death and re-hospitalization caused by heart failure at the 12th month, serum NT-proBNP, growth stimulation expressed gene 2 (ST2), and a change of right ventricular structure and function. ConclusionsThe PRIME-HFrEF study is designed to shed new light on multiple UC-MSC administration regimens for heart failure treatment.

The safety of magnetic resonance imaging contrast agents.

Gadolinium-based contrast agents are increasingly used in clinical practice. While these pharmaceuticals are verified causal agents in nephrogenic systemic fibrosis, there is a growing body of literature supporting their role as causal agents in symptoms associated with gadolinium exposure after intravenous use and encephalopathy following intrathecal administration. Gadolinium-based contrast agents are multidentate organic ligands that strongly bind the metal ion to reduce the toxicity of the metal. The notion that cationic gadolinium dissociates from these chelates and causes the disease is prevalent among patients and providers. We hypothesize that non-ligand-bound (soluble) gadolinium will be exceedingly low in patients. Soluble, ionic gadolinium is not likely to be the initial step in mediating any disease. The Kidney Institute of New Mexico was the first to identify gadolinium-rich nanoparticles in skin and kidney tissues from magnetic resonance imaging contrast agents in rodents. In 2023, they found similar nanoparticles in the kidney cells of humans with normal renal function, likely from contrast agents. We suspect these nanoparticles are the mediators of chronic toxicity from magnetic resonance imaging contrast agents. This article explores associations between gadolinium contrast and adverse health outcomes supported by clinical reports and rodent models.

An Unusual Case of CNS Tuberculoma in a 19-Year-Old Man

Background: Tuberculosis (TB) is ranked as one of the top 10 causes of death. Mycobacterium tuberculosis (M. TB) infection, the causative organism for TB affects approximately a quarter of the global population placing a burden on the healthcare system. Central nervous system tuberculosis (CNS TB) is seen in 5 to 10% of extrapulmonary TB cases and has the highest mortality. CNS tuberculoma is one of its manifestation. Clinical presentation of CNS tuberculoma depends on its location within the CNS and commonly include headache, seizures, and focal neurological deficits, due to the presence of a space occupying lesion, although patients can be asymptomatic. We report the case of a 19yr old man who had an unusual presentation of CNS tuberculoma, highlighting its clinical presentation, diagnosis and treatment. Case Presentation: Index patient is a 19-year-old male college student who resides in a city. He presented with 15 days history of fever, headache, vomiting, vertigo, ataxia, and inability to concentrate. He received antimalarial, anti typhoid and body booster medications but had no improvement and had a history of weight loss despite no dietary change. He had never been diagnosed with TB and had all his childhood vaccinations given. Plain Magnetic Resonance Imaging (MRI) brain scan done revealed a posterior fossa mass lesion with perilesional edema. Futher, a contrast MRI brain scan showed multiple ring-enhancing conglomerates of lesion around the tentorium on the posterior fossa with intense contrast enhancement. The largest of this mass measured 4.5 cm x 2.5 cm x 2.5 cm in the right superior cerebellum compressing the 4th ventricle and with effacement of the cerebellopontine angle. Lastly, an MRI spectrometry revealed elevated lipid lactate peak. His chest x-ray was unremarkable. Other blood parameters were essentially within range with the exception of Erythrocyte ESR and mantoux test. He received antitubercular drug (Isoniazid, Rifampin, Pyrazinamide, Ethambutol, Levoflox and Streptomycin) for 18th months with complete remission. Conclusion: CNS tuberculomas are tuberculous masses that can be located anywhere from the brain to spinal cord. Advanced diagnostic modalities may guide clinicians towards making it's diagnosis. Treatment maybe medical (use of antitubercular drugs) or surgical excision with medical therapy being first choice. While the index patient had no obvious risk factors for his disease, his BCG vaccination pose a possible source of his exposure to TB infection. More research is needed on this however.

Vital effects and the fractionation of rare earth elements and yttrium during uptake by and transfer within freshwater bivalves and their shells

Mussels are commonly used as bioarchives in environmental monitoring, yet the impact of vital effects on the trace element or isotope ratios used as biogeochemical proxies is often only ill constrained. A prime example of such trace elements are the Rare Earth elements and Yttrium (REY) which have become (micro)contaminants in freshwater systems worldwide. We here report on the distribution of REY in different soft tissues and in the shells of freshwater bivalve A. anatina, commonly known as “duck mussel”, from the Danube River in Hungary and the Vistula River in Poland. Both rivers are contaminated with anthropogenic Gd from contrast agents used in magnetic resonance imaging (MRI). Regardless of the mussels' origin, all of their compartments show very similar shale-normalised REY patterns. None of the samples show any anthropogenic Gd anomaly, implying that in freshwater anthropogenic Gd from MRI contrast agents is either not bioavailable or that REY from ambient river water are insignificant for the REY budget of freshwater mussels. Compared to ambient water, the bivalves bioaccumulate the REY with preferential uptake of Ce and of light REY over heavy REY. However, REY concentrations in mussels are similar to or lower than those in their potential food source, with minor fractionation along the REY series besides slight preferential uptake of La and Y. Comparison of shells and tissues reveals the systematic oxidative decoupling of Ce from its REY neighbours, probably due to the presence of Ce(IV) solution-complexes in the mussels' extrapallial fluid. Despite possible REY fractionation during their initial uptake, vital effects do not impose any major control on REY fractionation during REY transfer within the mussels or during formation of their shells. Mussel shells may, therefore, conveniently be used for environmental monitoring of REY without major disturbance from vital effects.