Association of contrast-enhanced MRI of inner ear and caloric response in patients with clinically diagnosed ipsilateral delayed endolymphatic hydrops.

BACKGROUND: Patients with delayed endolymphatic hydrops (DEH) often show caloric hypofunction and endolymphatic hydrops (ELH) on gadolinium (Gd) enhanced magnetic resonance imaging (MRI) of the inner ear. OBJECTIVES: We aimed to investigate the relationship between the ELH in vivo and caloric results in ipsilateral DEH. MATERIAL AND METHODS: Twelve patients with ipsilateral DEH were included, who underwent delayed MRI following intratympanic Gd application, pure-tone audiometry, caloric test, and video head impulse test (vHIT). RESULTS: For the affected ears, the overall prevalence of inner ear hydrops was 91.7%, including 75% in the cochlear and 50% in vestibular compartment. For the non-affected ears, the overall prevalence of inner ear hydrops was 25%, including 25% in cochlear and 16.7% in vestibular region. Caloric hypofunction was demonstrated in 75% of the affected ears. No pathologic vHIT were found. Caloric results were in agreement with the radiological evidence of inner ear hydrops on affected and non-affected ears in 9 cases. There was fair concordance between inner ear hydrops and canal paresis abnormality on the affected side. CONCLUSIONS AND SIGNIFICANCE: MRI provides auxiliary evidence of ELH in vivo in the ipsilateral DEH-affected ears. The association between morphological alterations and caloric hypofunction warrants further investigation.

The potential of Gd doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

The study shows that the addition of gadolinium ions has a significant impact on the structure, morphology, and adsorption properties of Ni-Co spinel ferrite that was synthesized by the sol-gel auto-combustion method. The research also indicates that the higher the Gd content, the greater the increase in the lattice parameter, which suggests that Gd3+ ions uniformly replaced the octahedral Fe3+ ions. The morphology and chemical composition of Gd-doped Ni-Co ferrites have been studied using SEM and EDS. Gd adding to the NiCoFe matrix increases the BET surface area by 50% (from 48 to 72 m2/g) and promotes the formation of mesopores with an average radius from 3.9 to 4.9 nm. The pHPZC values of Gd-doped ferrites are in the range of 7.22-7.39, which means that the ferrite surface will acquire a positive charge at natural pH, so this will promote the adsorption of Congo red anionic dye through electrostatic interaction forces. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to explain the mechanism of CR adsorption on the Ni0.5Co0.5GdxFe2-xO4 adsorbent surface. The ionic-covalent parameter has been estimated to describe the surface acid-base properties. Overall, this study highlights the potential of Gd3+ doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

Prediction of hepatocellular carcinoma in patients with Fontan-associated liver disease using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid magnetic resonance imaging.

AIM: The unique feature of Fontan circulation is elevated central venous pressure, which causes Fontan-associated liver disease (FALD). FALD is associated with a high incidence of hepatocellular carcinoma (HCC). Performing biopsies in patients with FALD is difficult as a result of warfarinization; gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI), a noninvasive examination, is useful for characterizing liver disease and detecting HCC. However, few studies have reported the detailed features of Gd-EOB-DTPA MRI, and the association between these findings and prognosis. Thus, this study aimed to investigate the utility of Gd-EOB-DTPA MRI to predict HCC development in patients with FALD. METHODS: This study enrolled 44 patients with FALD (mean age 25 years) who underwent Gd-EOB-DTPA MRI. The hepatobiliary phase images were scored semiqualitatively, and the patients were classified into the mild (0-1 point) or severe group (≥2 points). The endpoint was HCC, and event-free survival was analyzed using Kaplan-Meier and log-rank tests. RESULTS: The severe group included 19 patients. During a mean follow-up of 58 months, HCC developed in six patients. Kaplan-Meier analysis revealed that patients in the severe group had a significantly poorer prognosis than those in the mild group (p = 0.0053). The Fibrosis-4 index and liver-to-spleen ratio of patients with HCC were moderate. CONCLUSIONS: Gd-EOB-DTPA MRI can be used to classify disease severity and predict the prognosis of patients with FALD.

Electron microscopy evidence of gadolinium toxicity being mediated through cytoplasmic membrane dysregulation.

Past functional toxicogenomic studies have indicated that genes relevant to membrane lipid synthesis are important for tolerance to the lanthanides. Moreover, previously reported imaging of patient's brains following administration of gadolinium-based contrast agents shows gadolinium lining the vessels of the brain. Taken together, these findings suggest the disruption of cytoplasmic membrane integrity as a mechanism by which lanthanides induce cytotoxicity. In the presented work we used scanning transmission electron microscopy and spatially resolved elemental spectroscopy to image the morphology and composition of gadolinium, europium, and samarium precipitates that formed on the outside of yeast cell membranes. In no sample did we find that the lanthanide contaminant had crossed the cell membrane, even in experiments using yeast mutants with disrupted genes for sphingolipid synthesis-the primary lipids found in yeast cytoplasmic membranes. Rather, we evidence that lanthanides are co-located with phosphorus outside the yeast cells. These results lead us to hypothesize that the lanthanides scavenge or otherwise form complexes with phosphorus from the sphingophospholipid head groups in the cellular membrane, thereby compromising the structure or function of the membrane, and gaining the ability to disrupt membrane function without entering the cell.

Non-invasive imaging biomarkers in chronic liver disease.

Chronic liver disease (CLD) is a global and worldwide clinical challenge, considering that different underlying liver entities can lead to hepatic dysfunction. In the past, blood tests and clinical evaluation were the main noninvasive tools used to detect, diagnose and follow-up patients with CLD; in case of clinical suspicion of CLD or unclear diagnosis, liver biopsy has been considered as the reference standard to rule out different chronic liver conditions. Nowadays, noninvasive tests have gained a central role in the clinical pathway. Particularly, liver stiffness measurement (LSM) and cross-sectional imaging techniques can provide transversal information to clinicians, helping them to correctly manage, treat and follow patients during time. Cross-sectional imaging techniques, namely computed tomography (CT) and magnetic resonance imaging (MRI), have plenty of potential. Both techniques allow to compute the liver surface nodularity (LSN), associated with CLDs and risk of decompensation. MRI can also help quantify fatty liver infiltration, mainly with the proton density fat fraction (PDFF) sequences, and detect and quantify fibrosis, especially thanks to elastography (MRE). Advanced techniques, such as intravoxel incoherent motion (IVIM), T1- and T2- mapping are promising tools for detecting fibrosis deposition. Furthermore, the injection of hepatobiliary contrast agents has gained an important role not only in liver lesion characterization but also in assessing liver function, especially in CLDs. Finally, the broad development of radiomics signatures, applied to CT and MR, can be considered the next future approach to CLDs. The aim of this review is to provide a comprehensive overview of the current advancements and applications of both invasive and noninvasive imaging techniques in the evaluation and management of CLD.

Eosinopenia in patients with acute myocardial infarction- longitudinal imaging insights from the CAPRI study.

Eosinophils are recruited to the heart during acute myocardial infarction (MI) and are considered part of the inflammatory response associated with adverse clinical outcomes. We assessed the impact of eosinopenia on cardiac imaging biomarkers in patients presenting with ST-segment elevation MI. This is a post-hoc analysis of the Evaluating the effectiveness of intravenous Ciclosporin on reducing reperfusion injury in pAtients undergoing PRImary percutaneous coronary intervention (CAPRI) trial. Patients underwent cardiac MRI within 1 week and 12 weeks and low eosinophil was defined as less than 40 cells/ml. The study included 52 patients and 38% had low eosinophil. Ciclosporin administration was comparable between patients with low versus normal eosinophils. The ischaemia time was significantly longer in low eosinophil patients [262 (205-325) vs. 138 (102-195) minutes, P < 0.001]. At 12 weeks, patients with eosinopenia had larger infarct size [9.8% (5.7-18.4) vs. 7.4% (1.9-10.2), P = 0.045], larger left ventricle (LV) end systolic volume (89 ± 28 vs. 68 ± 23, P = 0.02), and lower LV ejection fraction (EF) (49 ± 9 vs. 58 ± 7, P < 0.001). After adjustments for significant predictors, including ischaemia time, low eosinophil count was an independent predictor of worse LVEF at 12 weeks [-5.78, 95% CI (-11.22 to -0.34), P = 0.038] but not infarct size [1.83, 95% CI (-2.77 to 6.43), P = 0.43]. Patients with low eosinophil count had larger infarct size and LV volumes and worse adverse remodeling compared to those with normal eosinophil count. At 12 weeks, eosinopenia was an independent predictor of worse LVEF but not infarct size.

Human performance in predicting enhancement quality of gliomas using gadolinium-free MRI sequences.

BACKGROUND AND PURPOSE: To develop and test a decision tree for predicting contrast enhancement quality and shape using precontrast magnetic resonance imaging (MRI) sequences in a large adult-type diffuse glioma cohort. METHODS: Preoperative MRI scans (development/optimization/test sets: n = 31/38/303, male = 17/22/189, mean age = 52/59/56.7 years, high-grade glioma = 22/33/249) were retrospectively evaluated, including pre- and postcontrast T1-weighted, T2-weighted, fluid-attenuated inversion recovery, and diffusion-weighted imaging sequences. Enhancement prediction decision tree (EPDT) was developed using development and optimization sets, incorporating four imaging features: necrosis, diffusion restriction, T2 inhomogeneity, and nonenhancing tumor margins. EPDT accuracy was assessed on a test set by three raters of variable experience. True enhancement features (gold standard) were evaluated using pre- and postcontrast T1-weighted images. Statistical analysis used confusion matrices, Cohen's/Fleiss' kappa, and Kendall's W. Significance threshold was p < .05. RESULTS: Raters 1, 2, and 3 achieved overall accuracies of .86 (95% confidence interval [CI]: .81-.90), .89 (95% CI: .85-.92), and .92 (95% CI: .89-.95), respectively, in predicting enhancement quality (marked, mild, or no enhancement). Regarding shape, defined as the thickness of enhancing margin (solid, rim, or no enhancement), accuracies were .84 (95% CI: .79-.88), .88 (95% CI: .84-.92), and .89 (95% CI: .85-.92). Intrarater intergroup agreement comparing predicted and true enhancement features consistently reached substantial levels (≥.68 [95% CI: .61-.75]). Interrater comparison showed at least moderate agreement (group: ≥.42 [95% CI: .36-.48], pairwise: ≥.61 [95% CI: .50-.72]). Among the imaging features in the EPDT, necrosis assessment displayed the highest intra- and interrater consistency (≥.80 [95% CI: .73-.88]). CONCLUSION: The proposed EPDT has high accuracy in predicting enhancement patterns of gliomas irrespective of rater experience.

Efficacy of photodynamic therapy using hematoporphyrin derivative nanomedicine on hepatocellular carcinoma cells.

Objective: To demonstrate the efficacy of photodynamic therapy (PDT) using hematoporphyrin derivative (HPD) nanomedicine in combination with conventional chemotherapy based on gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) magnetic resonance imaging (MRI) for hepatocellular carcinoma (HCC) therapy. Methods: HPD nanomedicine was prepared, and the cytotoxicity of HPD nanomedicine at different concentrations on HCC cells and the half-maximal inhibitory concentration (IC50) were analyzed. Sixty HCC patients who visited our hospital from 2021 to 2023 were retrospectively analyzed. Patient data were analyzed, with 30 cases in control group (CG) receiving conventional chemotherapy for HCC, and 30 cases in observation group (OG) receiving conventional chemotherapy combined with HPD nanomedicine PDT. Gd-DTPA MRI was utilized to monitor the morphological and biological characteristics of the lesions in patients. After treatment completion, the long-term efficacy of patients and the levels of bcl-2 and bax proteins in primary HCC cells were evaluated. Results: The IC50 values of HPD on HepG2 cell proliferation and the cell inhibition rates gradually increased with increasing doses of HPD (50 µM, 25 µM, 12.5 µM, 6.25 µM, 3.13 µM, 1.56 µM, 0.78 µM). HPD exhibited great anti-proliferative effects on HepG2 cells at relatively low concentrations. The differences in expression rates of bcl-2 protein and bax protein between groups were considerable (P<0.05). There were neglectable changes in AST and ALT levels between the two groups before treatment, but they were markedly reduced after treatment versus before treatment (P<0.05), with OG showing considerably lower levels than CG after treatment (P<0.05). Additionally, patients in OG exhibited better survival rates after the course of treatment versus those in CG. Conclusion: This study demonstrates that the combination of conventional chemotherapy based on Gd-DTPA MRI with HPD nanomedicine PDT greatly improves the efficacy of treatment for HCC patients. This combined treatment strategy not only enhances therapeutic outcomes but also alleviates adverse reactions associated with conventional treatment, providing a novel approach for future research in the treatment of HCC.

Cardiac remodeling and inflammation detected by magnetic resonance imaging in COVID-19 survivors.

Background: Concerns have been raised about cardiac inflammation in patients with long COVID-19, particularly those with myocardial injury during the acute phase of the disease. This study was conducted to examine myopericardial involvement, detected by cardiac magnetic resonance (CMR) imaging in patients hospitalized for COVID-19. Methods: Adult patients hospitalized with COVID-19 who presented myocardial injury or increased D-dimers were enrolled in this prospective study. All patients were invited to undergo CMR imaging examination after discharge. During follow-up, patients with nonischemic myocardial or pericardial involvement detected on the first CMR imaging examination underwent second examinations. CMR imaging findings were compared with those of a control group of healthy patients with no comorbidity. Results: Of 180 included patients, 53 underwent CMR imaging examination. The mean age was 58.4 ± 18.3 years, and 73.6 % were male. Myocardial and pericardial LGE was reported in 43.4 % and 35.8 % of patients, respectively. Nonischemic myocardial or pericardial involvement was reported in 26 (49.1 %) patients. The prevalence of pericardial LGE was associated inversely with the interval between hospital discharge and CMR. COVID-19 survivors had higher end-systolic volume indices (ESVis) and lower left-ventricular ejection fractions than did healthy controls. Seventeen patients underwent follow-up CMR imaging; the end-diastolic volume index, ESVi, and prevalence of pericardial LGE, but not that of nonischemic LGE, were reduced. Conclusion: Among COVID-19 survivors with myocardial injury during the acute phase of the disease, the incidences of nonischemic myocardial and pericardial LGE and CMR imaging-detected signs of cardiac remodeling, partially reversed during follow-up, were high.

The relationship between endolymphatic hydrops features and hearing loss in Bilateral Meniere's disease.

BACKGROUND: This study aimed to investigate the relationship between the features of endolymphatic hydrops and hearing loss in patients with Bilateral Meniere's Disease. METHODS: A retrospective analysis was conducted on 77 patients diagnosed with Bilateral Meniere's Disease. The features of endolymphatic hydrops in the affected ear were evaluated through gadolinium-enhanced inner ear Magnetic resonance imaging. The Spearman correlation coefficient, paired t-tests, and Wilcoxon signed-rank tests were employed for data analysis. RESULTS: The analysis revealed a significant correlation between the degree of endolymphatic hydrops and hearing loss across all frequencies(0.125-8 kHz), including the cochlear, vestibular, and overall degree of endolymphatic hydrops. The strongest correlation between the overall degree of endolymphatic hydrops and hearing loss was observed at low frequencies (r = 0.571, p < 0.05), followed by mid-frequencies (r = 0.508, p < 0.05), and high-frequencies (r = 0.351, p < 0.05), with a correlation of r = 0.463, p < 0.05 for the staging of Meniere's disease. Affected Ears with endolymphatic hydrops both in the cochlea and vestibule exhibited more severe hearing loss and Meniere's disease staging compared to those with isolated endolymphatic hydrops within the same patient. CONCLUSIONS: The features of endolymphatic hydrops in patients with Bilateral Meniere's Disease were found to correlate with the severity of hearing loss and the staging of Meniere's disease.

Cardiac manifestations and outcomes of COVID-19 vaccine-associated myocarditis in the young in the USA: longitudinal results from the Myocarditis After COVID Vaccination (MACiV) multicenter study.

Background: We aimed to study the clinical characteristics, myocardial injury, and longitudinal outcomes of COVID-19 vaccine-associated myocarditis (C-VAM). Methods: In this longitudinal retrospective observational cohort multicenter study across 38 hospitals in the United States, 333 patients with C-VAM were compared with 100 patients with multisystem inflammatory syndrome in children (MIS-C). We included patients ≤30 years of age with a clinical diagnosis of acute myocarditis after COVID-19 vaccination based on clinical presentation, abnormal biomarkers and/or cardiovascular imaging findings. Demographics, past medical history, hospital course, biochemistry results, cardiovascular imaging, and follow-up information from April 2021 to November 2022 were collected. The primary outcome was presence of myocardial injury as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging. Findings: Patients with C-VAM were predominantly white (67%) adolescent males (91%, 15.7 ± 2.8 years). Their initial clinical course was more likely to be mild (80% vs. 23%, p < 0.001) and cardiac dysfunction was less common (17% vs. 68%, p < 0.0001), compared to MIS-C. In contrast, LGE on CMR was more prevalent in C-VAM (82% vs. 16%, p < 0.001). The probability of LGE was higher in males (OR 3.28 [95% CI: 0.99, 10.6, p = 0.052]), in older patients (>15 years, OR 2.74 [95% CI: 1.28, 5.83, p = 0.009]) and when C-VAM occurred after the first or second dose as compared to the third dose of mRNA vaccine. Mid-term clinical outcomes of C-VAM at a median follow-up of 178 days (IQR 114-285 days) were reassuring. No cardiac deaths or heart transplantations were reported until the time of submission of this report. LGE persisted in 60% of the patients at follow up. Interpretation: Myocardial injury at initial presentation and its persistence at follow up, despite a mild initial course and favorable mid-term clinical outcome, warrants continued clinical surveillance and long-term studies in affected patients with C-VAM. Funding: The U.S. Food and Drug Administration.

Meta-analysis of cardiac magnetic resonance in prognosticating left ventricular function in peripartum cardiomyopathy.

AIMS: Peripartum cardiomyopathy (PPCM) may result in a number of detrimental adverse cardiovascular events, notably persistent left ventricular ejection fraction (LVEF) reduction or even mortality. Imaging parameters on cardiac magnetic resonance (CMR) and their prognostic implications have rarely been perused in PPCM. We aimed to describe CMR's prognostic value in predicting poor left ventricular (LV) function recovery using late gadolinium enhancement (LGE) and T2-weighted or T2 mapping. METHODS AND RESULTS: PubMed, Europe PMC, and ScienceDirect were screened for studies on late gadolinium enhancement (LGE) and myocardial oedema using CMR and PPCM. The outcome of interest was poor LV function recovery, with a follow-up period of at least 6 months. Comparisons between groups with the presence of LGE, myocardial oedema, and recovered against non-recovered patients were pooled. A random-effects model was employed to calculate the effect size. All pooled results were expressed as risk ratios (RRs) and 95% confidence intervals (CI). The area under the curve (AUC) was generated to test overall prognostic accuracy. Six cohort studies with 162 patients were included. The mean age of participants in this study was 30.6 years, and the majority of patients were diagnosed with PPCM after delivery. LGE was associated with a higher risk of poor LV function recovery, particularly when conducted at a later stage of disease (≥2.8 months) [RR = 2.83 (95% CI = 1.25-6.40); P = 0.001]. On the contrary, CMR conducted early (<2.8 months) exhibited a greater predictive value for myocardial oedema perceived by T2 mapping [RR = 3.44 (95% CI = 1.04-11.34); P = 0.043]. Diagnostic-test accuracy meta-analysis revealed that LGE had a sensitivity of 73% (95% CI, 56-85%), specificity of 79% (95% CI, 45-95%), and AUC of 0.78 (95% CI, 0.75-0.82) in predicting poor LV recovery when performed in the later phase, whereas significant myocardial oedema in those with non-recovered LV function had a sensitivity of 12% (95% CI, 2-52%), specificity of 68% (95% CI, 39-88%), and AUC of 0.40 (95% CI, 0.36-0.44) while undertaken in the latter phase. Our findings support the notion that inflammation plays a significant role in PPCM and that alterations to tissue composition occur in a time-dependent manner. CONCLUSIONS: Contrast-enhanced CMR can be utilized as an adjunct examination in post-partum PPCM patients to stratify the risk of poor LV function recovery while conducted at a suitable point in time.

Detangling past and modern zinc anthropogenic source contributions in an urbanized coastal river by combining elemental, isotope and speciation approaches.

The accumulation of trace metals in the environmental compartments of coastal rivers is a global and complex environmental issue, requiring multiple tools to constrain the various anthropogenic sources and biogeochemical processes affecting the water quality of these environments. The Valao fluvio-estuarine system (Rio de Janeiro, Brazil) presents a challenging case of a coastal river contaminated by both modern and historical anthropogenic metal sources, located in the land and in the intra-estuary, continuously mixed by tidal cycles. This study employed a combination of spatial distribution analysis of trace metals including gadolinium (Gd), zinc (Zn) isotopic analyses, and X-ray absorption spectroscopy (XAS) to distinguish between these sources. The concentrations of metals in both dissolved (water samples) and surficial sediment compartments (Suspended Particulate Matter and sediment samples) display an overall enrichment trend from upstream to downstream. Multivariate statistical analysis allows to discriminate geogenic elements derived from watershed geology (Ti, K, and Mg) vs anthropogenic contaminants from urban runoff and domestic sewage discharges (Cu, Cr, Pb, Zn, and Gd); and legacy metal contaminants (Zn and Cd) remobilized from ancient metallurgical wastes and transported upstream in the estuary during tidal cycles. The anthropogenic Gd concentration in the dissolved compartment increases along the watercourse, highlighting continuous ongoing sewage discharge. Zinc solid speciation also indicates that Zn contribution from legacy metallurgy waste is primarily associated with sulfide-Zn and Zn-phyllosilicate in the outlet estuary, while in upstream sediments of fluvio-estuarine system, Zn is found bound to organic matter. Zinc isotope systematically reveals a progressive downstream shift to heavier isotope compositions. Upstream, the relatively pristine site and the urbanized section of the river exhibit a relatively uniform δ66/64Zn value (+0.20 ± 0.07 ‰) in suspended particulate matter (SPM) and surficial sediments. These results indicate that domestic sewage discharges contribute to Zn enrichment in sediments of the Valao fluvio-estuarine system but without modifying its isotope signature in sediments. The sediment of the downstream estuarine section shows a heavier δ66/64Zn value (+0.48 ± 0.08 ‰), indicating the strong influence of the intra-estuarine source identified as the historical metallurgic contamination. An integrated view of the geochemical tracers allows thus inferring that the untreated sewage and legacy metallurgical contamination are the primary sources of anthropogenic Zn contamination. It highlights the progressive mixing along the estuarine gradient under tidal dynamics. The influence of the former source continuously expands from the headland towards the estuary.

Mitigating gadolinium toxicity in guar (Cyamopsis tetragonoloba L.) through the symbiotic associations with arbuscular mycorrhizal fungi: physiological and biochemical insights.

BACKGROUND: Gadolinium (Gd) is an increasingly found lanthanide element in soil; thus, understanding its impact on plant physiology, biochemistry, and molecular responses is crucial. Here, we aimed to provide a comprehensive understanding of Gd (150 mg kg- 1) impacts on guar (Cyamopsis tetragonoloba L.) plant yield and metabolism and whether the symbiotic relationship with arbuscular mycorrhizal fungi (AMF) can mitigate Gd toxicity of soil contamination. RESULTS: AMF treatment improved mineral nutrient uptake and seed yield by 38-41% under Gd stress compared to non-inoculated stressed plants. Metabolic analysis unveiled the defense mechanisms adopted by AMF-treated plants, revealing carbon and nitrogen metabolism adaptations to withstand Gd contamination. This included an increase in the synthesis of primary metabolites, such as total sugar (+ 39% compared to control), soluble sugars (+ 29%), starch (+ 30%), and some main amino acids like proline (+ 57%) and phenylalanine (+ 87%) in the seeds of AMF-treated plants grown under Gd contamination. Furthermore, fatty acid and organic acid profile changes were accompanied by the production of secondary metabolites, including tocopherols, polyamines, phenolic acids, flavones, and anthocyanins. CONCLUSIONS: Overall, the coordinated synthesis of these compounds underscores the intricate regulatory mechanisms underlying plant-AMF interactions and highlights the potential of AMF to modulate plant secondary metabolism for enhanced Gd stress tolerance.

Quantitative assessment of gadolinium deposition in dentate nuclei with MR fingerprinting.

RATIONALE AND OBJECTIVES: Gadolinium deposition in the dentate nucleus (DN) has been evaluated by T1-weighted imaging (T1WI) and T1 (R1) mapping, but not MR fingerprinting (MRF). This study investigated associations between T1 and T2 values of DN and gadolinium-based contrast agents (GBCAs) using 2-dimensional MRF. MATERIALS AND METHODS: This study included 101 patients. Region of interest analysis was performed for T1 and T2 values of DN on MRF (T1-MRF, T2-MRF) and T1-weighted images (T1WI ratio). T1 and T2 ratios compared to normal cerebellar white matter (T1-MRF ratio, T2-MRF ratio) were calculated. The type of previous GBCA was confirmed in 79 patients, and linear regressions were performed between T1, T2 values and number of GBCAs. RESULTS: Good correlations were observed between T1-MRF and T1WI ratio (ρ = -0.69, P < 0.001) and between T1-MRF ratio and T1WI ratio (ρ = -0.76, P < 0.001). Mild correlations were observed between T2-MRF and T1WI ratio (ρ = -0.32, P < 0.001) and between T2-MRF ratio and T1WI ratio (ρ = -0.44, P < 0.001). The number of linear-type GBCAs was associated with T1-MRF (ß = -0.62, P < 0.001) and T1-MRF ratio (ß = -0.54, P < 0.001) in univariate linear regression analyses, and with T1-MRF (ß = -0.61, P < 0.001) and T1-MRF ratio (ß = -0.53, P < 0.001) in multivariate analysis. The number of linear-type GBCAs was associated with T2-MRF (ß = -0.30, P < 0.001) and T2-MRF ratio (ß = -0.29, P < 0.001) in univariate analyses, and with T2-MRF (ß = -0.31, P < 0.001) and T2-MRF ratio (ß = -0.32, P < 0.001) in multivariate analyses. No associations were observed between number of macrocyclic GBCAs and T1-MRF (ratio) or T2-MRF (ratio). CONCLUSION: The number of linear-type GBCA administrations was associated with lower T1 and T2 values (ratios) in DN.

Relevance of increased negative T waves in apical hypertrophic cardiomyopathy with progressive myocardial damage: Insights from repeat cardiac magnetic resonance studies.

In patients with apical hypertrophic cardiomyopathy (HCM), progressive electrocardiographic changes are observed during long-term follow-up. However, it is difficult to correspond these changes to the specific myocardial changes. Cardiac magnetic resonance (CMR) imaging can elucidate myocardial changes by late gadolinium enhancement. Here, we present the long-term follow-up (>18 years) on a patient with apical HCM, whereupon, precise and continuous changes in the myocardium, causing ST segment and T wave changes on electrocardiography, were observed on CMR images. The combination of electrocardiography and CMR facilitates management of patients with apical HCM because it helps explain and understand the nature of electrocardiography changes over time.

Cardiac amyloidosis: A diagnostic challenge.

Cardiac amyloidosis is indeed a condition characterized by the deposition of amyloid proteins in the myocardium, leading to thickening and stiffening of the heart muscle. These abnormal protein deposits can interfere with the heart's normal functioning and may pose diagnostic challenges due to its varied clinical presentation and resemblance to other heart condition. Here, we present a case of 55-year-old female patient of uncontrolled hypertensions for 15 years. About 15 years ago, she presented with chest pain and was diagnosed with cardiomyopathy (CM) characterized by low left ventricle (LV) function of unknown cause. Despite being on antihypertensive treatment, the patient continued to experience chest heaviness with persistent elevate blood pressure. An echocardiogram revealed increased LV septal wall thickness, valvular thickening, and biatrial dilation. Subsequently, cardiac magnetic resonance imaging (CMR) was performed, which revealed left atrium enlargement and asymmetrical myocardial wall thickening, particularly at the septum. White blood axial image revealed thickened inter atrial septum, while late gadolinium enhancement (LGE) magnetic resonance (LGE MR) images showed patchy LGE at the base relative to the apex of the myocardium, highlighting the base-to-apex gradient, subendocardial pattern enhancement at apical lateral wall, and transmural pattern enhancement of the mid anteroseptal and inferoseptal wall. Additionally, a short axis time to invert T1 scout image of left ventricle displayed an abnormal nulling pattern initially in the myocardium, followed by the blood pool, and finally the spleen. These findings collectively led to the diagnosis of cardiac amyloidosis.

Peripartum Cardiomyopathy is Associated With Abnormalities of Myocardial Deformation and Late Gadolinium Enhancement.

Purpose: Peripartum cardiomyopathy (PPCM) affects women in late pregnancy and postpartum. Cardiovascular magnetic resonance (CMR) can contribute to PPCM diagnosis and management. We explored CMR findings in PPCM, including myocardial strain and late gadolinium enhancement (LGE) patterns. Materials and Methods: This retrospective single-centre study included patients with PPCM who underwent CMR from 2010 to 2018. Exclusions were other cardiomyopathy causes. CMR parameters, including ventricular function, LGE, and myocardial strain, were compared between the PPCM group and healthy controls. Transthoracic echocardiographic data were reviewed to assess functional improvement in PPCM patients. Results: Thirty-two women with PPCM (mean age 42 ± 6 years) and 26 controls (mean age 43 ± 14 years) were included. PPCM patients had significantly lower left ventricular (LV) ejection fractions (median 37.5% vs 60.5%, P < .001), higher LV end-diastolic volumes (median 108 ml/m² vs 76 ml/m², P < .001), and reduced global LV strain compared to controls. Eighteen PPCM patients (58%) had non-ischaemic pattern LGE, with no LGE in controls besides hingepoint LGE (23%). LGE was most prevalent in the basal and mid anteroseptum. LGE patterns included linear mid-wall, subepicardial, and right ventricular side of the septum. Twenty-four patients (92%) showed improvement in LVEF at follow-up echocardiogram (mean LVEF 28% ± 1.9% at diagnosis and 45% ± 3% at follow-up, P < .001). Conclusion: We identified a non-ischaemic pattern LGE that is nonspecific in isolation but could suggest PPCM in the correct clinical context along with abnormal CMR strain values. Future studies should evaluate the clinical application of these findings to facilitate earlier diagnosis and enhance management.

Non-invasive diagnosis of liver fibrosis via MRI using targeted gadolinium-based nanoparticles.

INTRODUCTION: Accurate diagnosis of liver fibrosis is crucial for preventing cirrhosis and liver tumors. Liver fibrosis is driven by activated hepatic stellate cells (HSCs) with elevated CD44 expression. We developed hyaluronic acid (HA)-coated gadolinium-based nanoprobes to specifically target CD44 for diagnosing liver fibrosis using T1-weighted magnetic resonance imaging (MRI). MATERIALS AND METHODS: NaGdF4 nanoparticles (NPs) were synthesized via thermal decomposition and modified with polyethylene glycol (PEG) to obtain non-targeting NaGdF4@PEG NPs. These were subsequently coated with HA to target HSCs, resulting in liver fibrosis-targeting NaGdF4@PEG@HA nanoprobes. Characterization includedd transmission electron microscopy and X-ray diffraction. Cell viability was assessed using the Cell Counting Kit-8 (CCK-8). Internalization of NaGdF4@PEG@HA nanoprobes by mouse HSCs JS1 cells via ligand-receptor interaction was observed using flow cytometry and confocal laser scanning microscopy (CLSM). Liver fibrosis was induced in C57BL/6 mice using a methionine-choline deficient (MCD) diet. MRI performance and nanoprobe distribution in fibrotic and normal livers were analyzed using a GE Discovery 3.0T MR 750 scanner. RESULTS: NaGdF4@PEG@HA nanoprobes exhibited homogeneous morphology, low toxicity, and a high T1 relaxation rate (7.645 mM⁻¹s⁻¹). CLSM and flow cytometry demonstrated effective phagocytosis of NaGdF4@PEG@HA nanoprobes by JS1 cells compared to NaGdF4@PEG. MRI scans revealed higher T1 signals in fibrotic livers compared to normal livers after injection of NaGdF4@PEG@HA. NaGdF4@PEG@HA demonstrated higher targeting ability in fibrotic mice. CONCLUSIONS: NaGdF4@PEG@HA nanoprobes effectively target HSCs with high T1 relaxation rate, facilitating efficient MRI diagnosis of liver fibrosis.