Imaging evaluation and volumetric measurement of the space surrounding the diploic veins.

PURPOSE: The diploic veins have been suggested to be involved in the excretion of cerebrospinal fluid and intracranial waste products; however, to date, there have been no reports evaluating the space surrounding the diploic veins. Therefore, we aimed to visualize the distribution of gadolinium-based contrast agent (GBCA) in the space surrounding the diploic veins and to evaluate the spatial characteristics. MATERIALS AND METHODS: Ninety-eight participants (aged 14-84 years) were scanned 4 h after intravenous GBCA injection at Nagoya University Hospital between April 2021 and December 2022. The volume of the space surrounding the diploic veins where the GBCA was distributed was measured using contrast-enhanced T1-weighted images with the application of three-axis motion-sensitized driven equilibrium. The parasagittal dura (PSD) volume adjacent to the superior sagittal sinus was also measured using the same images. Both volumes were corrected for intracranial volume. The correlation between age and the corrected volume was examined using Spearman's rank correlation coefficient; the relationship between the corrected volume and sex was assessed using the Mann-Whitney U test. RESULTS: A significant weak negative correlation was observed between the volume of the space surrounding the diploic veins and age (r = -0.330, p < 0.001). Furthermore, there was a significant weak positive correlation between the PSD volume and age (r = 0.385, p < 0.001). Both volumes were significantly greater in men than in women. There was no correlation between the volume of the space surrounding the diploic veins and the volume of the PSD. CONCLUSION: The volume of the space surrounding the diploic veins was measurable and, in contrast to the volume of the PSD, was greater in younger participants. This space may be related to intracranial excretory mechanisms and immune responses during youth, requiring further research.

Cardiac Magnetic Resonance Imaging as a Risk Stratification Tool in COVID-19 Myocarditis.

The aim of this retrospective study was to identify myocardial injury after COVID-19 inflammation and explore whether myocardial damage could be a possible cause of the persistent symptoms following COVID-19 infection in previously healthy individuals. This study included 139 patients who were enrolled between January and June 2021, with a mean age of 46.7 ± 15.2 years, of whom 68 were men and 71 were women without known cardiac or pulmonary diseases. All patients underwent clinical work-up, laboratory analysis, cardiac ultrasound, and CMR on a 1.5 T scanner using a recommended protocol for morphological and functional assessment before and after contrast media application with multi-parametric sequences. In 39% of patients, late gadolinium enhancement (LGE) was found as a sign of myocarditis. Fibrinogen was statistically significantly higher in patients with LGE than in those without LGE (4.3 ± 0.23 vs. 3.2 ± 0.14 g/L, p < 0.05, respectively), as well as D-dimer (1.8 ± 0.3 vs. 0.8 ± 0.1 mg/L FEU). Also, troponin was statistically significantly higher in patients with myocardial LGE (13.1 ± 0.4 ng/L) compared to those with normal myocardium (4.9 ± 0.3 ng/L, p < 0.001). We demonstrated chest pain, fatigue, and elevated troponin to be independent predictors for LGE. Septal LGE was shown to be a predictor for arrhythmias. The use of CMR is a potential risk stratification tool in evaluating outcomes following COVID-19 myocarditis.

Evaluation of signal intensity changes in dentate nucleus and globus pallidus on magnetic resonance imaging after intrathecal gadolinium-based contrast agent administration.

PURPOSE: Gadolinium deposition has been reported in several normal anatomical structures in the brain after repeated administration of intravenous gadolinium-based contrast agents (GBCAs) used in magnetic resonance imaging (MRI). This study presents preliminary results to see if there is any gadolinium deposition in the dentate nucleus and globus pallidus after using intrathecal GBCAs. METHODS: Between November 2018 and November 2020, 29 patients who underwent intrathecal contrast-enhanced MR cisternography with the suspicion of rhinorrhea were included in this prospective study. In contrast-enhanced MR cisternography, gadoterate meglumine was administered by intrathecal injection at a dose of 1 ml. One month later, patients had a control MRI with 3D T1 SPACE fat-saturated (FS) and susceptibility weighted images (SWI) sequences. The ratio of dentate nucleus signal intensity to middle cerebellar peduncle signal intensity (DN/MCP ratio) and the ratio of globus pallidus signal intensity to thalamus signal intensity (GP/T ratio) were calculated using region of interest (ROI) on pre-contrast and control MRI sequences. RESULTS: There was no significant difference for DN/MCP ratio and GP/T ratio on 3D T1 SPACE FS and SWI sequences after intrathecal GBCAs administration compared to baseline MRI. CONCLUSION: Administration of intrathecal GBCAs did not cause a measurable change in the signal intensity of the dentate nucleus and globus pallidus after a single injection.

The role of cardiac magnetic resonance in sports cardiology: results from a large cohort of athletes.

BACKGROUND: Cardiac magnetic resonance (CMR) provides information on morpho-functional abnormalities and myocardial tissue characterisation. Appropriate indications for CMR in athletes are uncertain. OBJECTIVE: To analyse the CMR performed at our Institute to evaluate variables associated with pathologic findings in a large cohort of athletes presenting with different clinical conditions. METHODS: All the CMR performed at our Institute in athletes aged > 14 years were recruited. CMR indications were investigated. CMR was categorised as "positive" or "negative" based on the presence of morphological and/or functional abnormalities and/or the presence of late gadolinium enhancement (excluding the right ventricular insertion point), fat infiltration, or oedema. Variables associated with "positive" CMR were explored. RESULTS: A total of 503 CMR were included in the analysis. "Negative" and "positive" CMR were 61% and 39%, respectively. Uncommon ventricular arrhythmias (VAs) were the most frequent indications for CMR, but the proportion of positive results was low (37%), and only polymorphic ventricular patterns were associated with positive CMR (p = 0.006). T-wave inversion at 12-lead ECG, particularly on lateral and inferolateral leads, was associated with positive CMR in 34% of athletes (p = 0.05). Echocardiography abnormalities resulted in a large proportion (58%) of positive CMR, mostly cardiomyopathies. CONCLUSION: CMR is more efficient in identifying a pathologic cardiac substrate in athletes in case of VAs (i.e., polymorphic beats), abnormal ECG repolarisation (negative T-waves in inferolateral leads), and borderline echocardiographic findings (LV hypertrophy, mildly depressed LV function). On the other hand, CMR is associated with a large proportion of negative results. Therefore, a careful clinical selection is needed to indicate CMR in athletes appropriately.

How often should we perform magnetic resonance imaging (MRI) for the follow-up of pituitary adenoma?

Magnetic resonance imaging (MRI) is the examination of choice for diagnosing and monitoring pituitary adenoma (also known as pituitary neuroendocrine tumor or PitNET), whether treated or not. However, repeating the examination too often (and sometimes unnecessarily) is costly, and worrying data on tissue accumulation (brain, bone, etc.) of gadolinium atoms dissociated from their carrier molecule (chelator) have led European authorities to ban contrast agents based on linear chelators of gadolinium, which are particularly susceptible to rapid dissociation, in favor of chemically more stable macrocyclic chelators. It is therefore important to determine the optimal frequency for pituitary MRI monitoring in order to safely assess the natural history or therapeutic response of pituitary adenomas. The aim of this article is to summarize the most recent data on optimal follow-up intervals depending on the type, size and location of the pituitary tumor and the clinical situation in general, in order to generate monitoring algorithms to guide clinicians.

Development and Characterization of Gadolinium and Copper Reinforced Bioactive Glass: An In Vitro Study.

INTRODUCTION: Bioactive glass, an innovative alloplastic material utilizing a matrix of silica particles combined with calcium and phosphorus, has been widely employed for the regeneration of bony defects due to its bone-forming capabilities and biocompatibility. Nevertheless, it comes with several drawbacks, including a slow degradation rate, low mechanical strength, and susceptibility to fractures. To address these issues, the present research was done to develop and characterize a novel bioactive glass incorporating gadolinium (Gd) and copper (Cu). METHODS: The bioactive glass doped with Gd and Cu were synthesized and subjected to characterization through X-ray diffraction (XRD), scanning electron microscopy (SEM), and attenuated total reflectance-infrared (ATR-IR) analysis. RESULTS: The bioactive glass, enriched with Gd and Cu, underwent analysis using ATR-IR spectroscopy, XRD, and SEM. ATR-IR revealed characteristic silicate bands, while SEM indicated the presence of particles larger than 4 µm. XRD analysis identified the formation of Na2Ca4(PO4)2SiO4 (Silicorhenatite), Na2Ca2Si3O9 (Combeite), and wollastonite (calcium inosilicate mineral; CaSiO3). The crystalline nature of these compounds contributed to the favorable mechanical properties of the bioactive glass. CONCLUSION: In summary, the creation of the innovative Gd-Cu-incorporated bioactive glass demonstrates favorable mechanical characteristics, suggesting significant promise for augmenting bone regeneration.

Fibrosis modeling choice affects morphology of ventricular arrhythmia in non-ischemic cardiomyopathy.

Introduction: Patients with non-ischemic cardiomyopathy (NICM) are at risk for ventricular arrhythmias, but diagnosis and treatment planning remain a serious clinical challenge. Although computational modeling has provided valuable insight into arrhythmic mechanisms, the optimal method for simulating reentry in NICM patients with structural disease is unknown. Methods: Here, we compare the effects of fibrotic representation on both reentry initiation and reentry morphology in patient-specific cardiac models. We investigate models with heterogeneous networks of non-conducting structures (cleft models) and models where fibrosis is represented as a dense core with a surrounding border zone (non-cleft models). Using segmented cardiac magnetic resonance with late gadolinium enhancement (LGE) of five NICM patients, we created 185 3D ventricular electrophysiological models with different fibrotic representations (clefts, reduced conductivity and ionic remodeling). Results: Reentry was induced by electrical pacing in 647 out of 3,145 simulations. Both cleft and non-cleft models can give rise to double-loop reentries meandering through fibrotic regions (Type 1-reentry). When accounting for fibrotic volume, the initiation sites of these reentries are associated with high local fibrotic density (mean LGE in cleft models: p< 0.001, core volume in non-cleft models: p = 0.018, negative binomial regression). In non-cleft models, Type 1-reentries required slow conduction in core tissue (non-cleftsc models) as opposed to total conduction block. Incorporating ionic remodeling in fibrotic regions can give rise to single- or double-loop rotors close to healthy-fibrotic interfaces (Type 2-reentry). Increasing the cleft density or core-to-border zone ratio in cleft and non-cleftc models, respectively, leads to increased inducibility and a change in reentry morphology from Type 2 to Type 1. Conclusions: By demonstrating how fibrotic representation affects reentry morphology and location, our findings can aid model selection for simulating arrhythmogenesis in NICM.

Direct Visualization of Tracer Permeation into the Endolymph in Human Patients Using MR Imaging.

PURPOSE: The endolymph of the inner ear, vital for balance and hearing, has long been considered impermeable to intravenously administered gadolinium-based contrast agents (GBCAs) due to the tight blood-endolymph barrier. However, anecdotal observations suggested potential GBCA entry in delayed heavily T2-weighted 3D-real inversion recovery (IR) MRI scans. This study systematically investigated GBCA distribution in the endolymph using this 3D-real IR sequence. METHODS: Forty-one patients suspected of endolymphatic hydrops (EHs) underwent pre-contrast, 4-h, and 24-h post-contrast 3D-real IR imaging. Signal intensity in cerebrospinal fluid (CSF), perilymph, and endolymph was measured and analyzed for temporal dynamics of GBCA uptake, correlations between compartments, and the influence of age and presence of EH. RESULTS: Endolymph showed a delayed peak GBCA uptake at 24h, contrasting with peaks in perilymph and CSF at 4h. Weak to moderate positive correlations between endolymph and CSF contrast effect were observed at both 4 (r = 0.483) and 24h (r = 0.585), suggesting possible inter-compartmental interactions. Neither the presence of EH nor age significantly influenced endolymph enhancement. However, both perilymph and CSF contrast effects significantly correlated with age at both time points. CONCLUSION: This study provides the first in vivo systematic confirmation of GBCA entering the endolymph following intravenous administration. Notably, endolymph uptake peaked at 24h, significantly later than perilymph and CSF. The lack of a link between endolymph contrast and both perilymph and age suggests distinct uptake mechanisms. These findings shed light on inner ear fluid dynamics and their potential implications in Ménière's disease and other inner ear disorders.

Reliable differentiation of necrosis and active metabolically contours of glioblastoma multiforme using susceptibility-based imaging.

Purpose: Gadolinium-enhancing necrosis in glioblastoma multiforme (GBM), as an occasionally occurring false positive in contrast enhancement (CE) imaging, leads to trouble for segmentation of GBM and treatment. Therefore, the investigation of complementary detection way to identify the metabolically active volume of the tumor with high reliability is very worth to be addressed. Here, we reported on a case of GBM with gadolinium-enhancing necrosis in an experimental CE imaging study in mice and evaluated the discrimination of the necrosis and metabolically active parts of the GBM using conventional and state-of-the-art susceptibility-based MRI. Methods: In this study, following 5-aminolevulinic acid (ALA) and iron supplements (FAC, 6 h after ALA, intra-tumoral injection) to animal, T2*-W imaging and quantitative susceptibility mapping (QSM) were performed, and compared with CE imaging. Results: The signal intensity (SI) of the active and necrosis areas of the case in the CE image demonstrated no significant difference while the SI on the T2*-W images and susceptibility value in QSM changed 24 and 150%, respectively. Conclusion: The preclinical case report provides valuable insights into the potential of susceptibility-based MRI using ALA + FAC to apply as a robust discriminator between necrotic and viable tumors.

Clear cell hepatocellular carcinoma: Gd-EOB-DTPA-enhanced MR imaging features and prognosis.

PURPOSE: To investigate imaging findings on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-enhanced MRI) and prognosis of clear cell hepatocellular carcinoma (CCHCC) comparing with non-otherwise specified hepatocellular carcinoma (NOS-HCC). METHODS: The clinical, pathological and MR imaging features of 42 patients with CCHCC and 84 age-matched patients with NOS-HCC were retrospectively analyzed from January 2015 to October 2021. Univariate and multivariate logistic regression and Cox regression analyses were performed to identify independent diagnostic and prognostic factors for CCHCC. Disease-free survival (DFS) and overall survival (OS) were determined by Kaplan-Meier analysis. RESULTS: CCHCC showed fat content more frequently (P < 0.001) and relatively higher Edmondson tumor grade (P = 0.001) compared with NOS-HCC. The lesion-to-muscle ratio (LMR) and lesion-to-liver ratio (LLR) of CCHCC on pre-enhancement T1-weighted imaging (pre-T1WI) (P = 0.001, P = 0.003) and hepatobiliary phase (HBP) (P = 0.007, P = 0.048) were significantly higher than those of NOS-HCC. The area under the curve (AUC) for fat content, LLR on pre-T1WI and their combination with better diagnostic performance in predicting CCHCC were 0.678, 0.666, and 0.750, respectively. There was no statistically significant difference in clinical outcomes between CCHCC and NOS-HCC. Multivariate Cox analysis confirmed that tumor size > 2 cm and enhancing capsule were independent prognostic factors for DFS and OS among CCHCC patients. CONCLUSION: Fat content and adjusted lesion signal intensity on pre-T1WI and HBP could be used to differentiate CCHCC from NOS-HCC. CCHCC had similar prognosis with NOS-HCC.

Biventricular Impairment and Ventricular Interdependence in Patients With Alcoholic Cardiomyopathy: Insights Through Cardiac Magnetic Resonance Imaging.

BACKGROUND: Alcoholic cardiomyopathy (ACM) can lead to progressive cardiac dysfunction and heart failure, but little is known about biventricular impairment and ventricular interdependence (VI) in ACM patients. PURPOSE: To use cardiac MRI to investigate biventricular impairment and VI in ACM patients. STUDY TYPE: Retrospective. POPULATION: Forty-one male patients with ACM and 45 sex- and age-matched controls. FIELD STRENGTH/SEQUENCE: 3.0 T/balanced steady-state free precession sequence, inversion recovery prepared echo-planar imaging sequence and phase-sensitive inversion recovery sequence. ASSESSMENT: Biventricular structure, function, and global strain (encompassing peak strain [PS], peak systolic, and diastolic strain rate), PS of interventricular septal (IVS), microvascular perfusion (including upslope and time to maximum signal intensity [TTM]), late gadolinium enhancement (LGE), and baseline characteristics were compared between the controls and ACM patients. STATISTICAL TESTS: Student's t-test, Mann-Whitney U test, Pearson's correlation, and multivariable linear regression models with a stepwise selection procedure. A two-tailed P value <0.05 was deemed as statistically significant. RESULTS: Compared to control subjects, ACM patients showed significantly biventricular adverse remodeling, reduced left ventricle (LV) global upslope and prolonged global TTM, and the presence of LGE. ACM patients were characterized by a significant decline in all global strain within the LV, right ventricle (RV), and IVS compared with the controls. RV global PS was significantly associated with LV global PS and IVS PS in radial, circumferential, and longitudinal directions. Multivariable analyses demonstrated the longitudinal PS of IVS was significantly correlated with RV global radial PS (ß = 0.614) and circumferential PS (ß = 0.545). Additionally, RV global longitudinal PS (GLPS) was significantly associated with radial PS of IVS (ß = -0.631) and LV GLPS (ß = 1.096). DATA CONCLUSION: ACM patients exhibited biventricular adverse structural alterations and impaired systolic and diastolic function. This cohort also showed reduced LV microvascular perfusion, the presence of LGE, and unfavorable VI. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 3.

Penetrance of Dilated Cardiomyopathy in Genotype-Positive Relatives.

BACKGROUND: Disease penetrance in genotype-positive (G+) relatives of families with dilated cardiomyopathy (DCM) and the characteristics associated with DCM onset in these individuals are unknown. OBJECTIVES: This study sought to determine the penetrance of new DCM diagnosis in G+ relatives and to identify factors associated with DCM development. METHODS: The authors evaluated 779 G+ patients (age 35.8 ± 17.3 years; 459 [59%] females; 367 [47%] with variants in TTN) without DCM followed at 25 Spanish centers. RESULTS: After a median follow-up of 37.1 months (Q1-Q3: 16.3-63.8 months), 85 individuals (10.9%) developed DCM (incidence rate of 2.9 per 100 person-years; 95% CI: 2.3-3.5 per 100 person-years). DCM penetrance and age at DCM onset was different according to underlying gene group (log-rank P = 0.015 and P <0.01, respectively). In a multivariable model excluding CMR parameters, independent predictors of DCM development were: older age (HR per 1-year increase: 1.02; 95% CI: 1.0-1.04), an abnormal electrocardiogram (HR: 2.13; 95% CI: 1.38-3.29); presence of variants in motor sarcomeric genes (HR: 1.92; 95% CI: 1.05-3.50); lower left ventricular ejection fraction (HR per 1% increase: 0.86; 95% CI: 0.82-0.90) and larger left ventricular end-diastolic diameter (HR per 1-mm increase: 1.10; 95% CI: 1.06-1.13). Multivariable analysis in individuals with cardiac magnetic resonance and late gadolinium enhancement assessment (n = 360, 45%) identified late gadolinium enhancement as an additional independent predictor of DCM development (HR: 2.52; 95% CI: 1.43-4.45). CONCLUSIONS: Following a first negative screening, approximately 11% of G+ relatives developed DCM during a median follow-up of 3 years. Older age, an abnormal electrocardiogram, lower left ventricular ejection fraction, increased left ventricular end-diastolic diameter, motor sarcomeric genetic variants, and late gadolinium enhancement are associated with a higher risk of developing DCM.

[A case of neurosarcoidosis initially diagnosed as cervical spondylotic myelopathy, leading to diagnosis by gadolinium contrast-enhanced MRI].

A 70-year-old female presented with bilateral numbness in her upper limbs. She was diagnosed with cervical spondylotic myelopathy and underwent cervical laminoplasty. However, there was no significant improvement in sensory disturbance, and at 6 months after surgery, she developed subacute motor and gait disturbance in four extremities. Spinal MRI revealed a long lesion of the spinal cord with edema, and a part of the lesion showed gadolinium contrast enhancement. Bronchoscopy revealed an elevated CD4/8 ratio, and gallium scintigraphy demonstrated an accumulation in the hilar lymph nodes, leading to a diagnosis of neurosarcoidosis. In case of rapid deterioration during the course of cervical spondylotic myelopathy, neurosarcoidosis should be considered as a differential diagnosis, which can be assessed by contrast-enhanced MRI.

Spontaneous intracranial hypotension: Exploring the viability of non-contrast FLAIR as a substitute for contrast-enhanced T1WI in assessing pachymeningeal thickening.

PURPOSE: To avoid contrast administration in spontaneous intracranial hypotension (SIH), some studies suggest accepting diffuse pachymeningeal hyperintensity (DPMH) on non-contrast fluid-attenuated inversion recovery (FLAIR) as an equivalent sign to diffuse pachymeningeal enhancement (DPME) on contrast-enhanced T1WI (T1ce), despite lacking thorough performance metrics. This study aimed to comprehensively explore its feasibility. METHODS: In this single-center retrospective study, between April 2021 and November 2023, brain MRI examinations of 43 patients clinically diagnosed with SIH were assessed using 1.5 and 3.0 Tesla MRI scanners. Two radiologists independently assessed the presence or absence of DPMH on FLAIR and DPME on T1ce, with T1ce serving as a gold-standard for pachymeningeal thickening. The contribution of the subdural fluid collections to DPMH was investigated with quantitative measurements. Using Cohen's kappa statistics, interobserver agreement was assessed. RESULTS: In 39 out of 43 patients (90.7%), pachymeningeal thickening was observed on T1ce. FLAIR sequence produced an accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 72.1%, 71.8%, 75.0%, 96.6%, and 21.4% respectively, for determining pachymeningeal thickening. FLAIR identified pachymeningeal thickening in 28 cases; however, among these, 21 cases (75%) revealed that the pachymeningeal hyperintense signal was influenced by subdural fluid collections. False-negative rate for FLAIR was 28.2% (11/39). CONCLUSION: The lack of complete correlation between FLAIR and T1ce in identifying pachymeningeal thickening highlights the need for caution in removing contrast agent administration from the MRI protocol of SIH patients, as it reveals a major criterion (i.e., pachymeningeal enhancement) of Bern score.

Gadolinium-based contrast agents aggravate mechanical and thermal hyperalgesia in a nitroglycerine-induced migraine model in male mice.

In the diagnosis of migraine, which is a neurovascular disease, gadolinium-based contrast agents (GBCAs) are used to rule out more serious conditions. On the other hand, it remains unclear as a scientific gap whether GBCAs may trigger migraine-related pain. The aim of this study was to investigate the effect of GBCAs on mechanical and thermal pain behaviour in a nitroglycerin (NTG)-induced migraine model in mice. NTG (10 mg/kg) was administered intraperitoneally to adult (6-8weeks old) BALB/c mice 2 h before behavioral tests 5 times every other day on days 1st, 3rd, 5th and 9th to induce migraine model (N = 50). As GBCAs, gadobenate dimeglumine (linear-ionic), Gadodiamide (linear-nonionic), and gadobutrol (macrocyclic-nonionic) were delivered intravenously through the tail vein of mice for 5 days on test days. Mechanical pain threshold (plantar and facial withdrawal threshold) was evaluated by plantar von Frey and periorbital von Frey tests on days 1st, 5th, and 9th, and thermal pain threshold (latency) was evaluated by hot plate and cold plate tests on days 3rd and 7th. There was a statistically significant increase in mechanical and thermal hyperalgesia in NTG administered groups compared to the control group. Gadodiamide, gadobutrol and gadobenate dimeglumine administration significantly decreased latency, paw and facial withdrawal threshold (0.18 ± 0.05, 0.17 ± 0.07, 0.16 ± 0.09; 9th day values respectively) compared to NTG group (0.27 ± 0.05). The results of this in vivo study show that GBCAs produce effects that may trigger migraine attacks in migraine. It is recommended that these effects be further investigated and supported by further clinical studies.

Toxicity Mechanisms of Gadolinium and Gadolinium-Based Contrast Agents-A Review.

Gadolinium-based contrast agents (GBCAs) have been used for more than 30 years to improve magnetic resonance imaging, a crucial tool for medical diagnosis and treatment monitoring across multiple clinical settings. Studies have shown that exposure to GBCAs is associated with gadolinium release and tissue deposition that may cause short- and long-term toxicity in several organs, including the kidney, the main excretion organ of most GBCAs. Considering the increasing prevalence of chronic kidney disease worldwide and that most of the complications following GBCA exposure are associated with renal dysfunction, the mechanisms underlying GBCA toxicity, especially renal toxicity, are particularly important. A better understanding of the gadolinium mechanisms of toxicity may contribute to clarify the safety and/or potential risks associated with the use of GBCAs. In this work, a review of the recent literature concerning gadolinium and GBCA mechanisms of toxicity was performed.

Trajectories of functional and structural myocardial parameters in post-COVID-19 syndrome-insights from mid-term follow-up by cardiovascular magnetic resonance.

Introduction: Myocardial tissue alterations in patients with post-Coronavirus disease 2019 syndrome (PCS) are often subtle and mild. Reports vary in the prevalence of non-ischemic and ischemic injuries as well as the extent of ongoing myocardial inflammation. The exact relevance of these myocardial alterations is not fully understood. This study aimed at describing the trajectories of myocardial alterations in PCS patients by mid-term follow-up with cardiovascular magnetic resonance (CMR). Methods: This study entails a retrospective analysis of symptomatic PCS patients referred for follow-up CMR between August 2020 and May 2023 due to mildly affected or reduced left or right ventricular function (LV and RV, respectively) and structural myocardial alterations, e.g., focal and diffuse fibrosis, on baseline scans. Follow-up CMR protocol consisted of cine images and full coverage native T1 and T2 mapping. Baseline and follow-up scans were compared using t-tests or Wilcoxon tests. Post-hoc analysis was carried out in a subgroup based on the change of LV stroke volume (SV) between scans. Results: In total, 43 patients [median age (interquartile range) 46 (37-56) years, 33 women] received follow-ups 347 (167-651) days after initial diagnosis. A decrease in symptoms was recorded on follow-ups (p < 0.03) with 23 patients being asymptomatic at follow-ups [symptomatic at baseline 43/43 (100%) vs. symptomatic at follow-up 21/43 (49%), p < 0.001]. Functional improvement was noted for LV-SV [83.3 (72.7-95.0) vs. 84.0 (77.0-100.3) ml; p = 0.045], global radial [25.3% (23.4%-27.9%) vs. 27.4% (24.4%-33.1%); p < 0.001], and circumferential strains [-16.5% (-17.5% to -15.6%) vs. -17.2% (-19.5% to -16.1%); p < 0.001]. In total, 17 patients had an LV-SV change >10% on follow-up scans (5 with a decrease and 12 with an increase), with LV-SV, RV-SV, and global longitudinal strain being discriminatory variables on baseline scans (p = 0.01, 0.02, and 0.04, respectively). T1- or T2-analysis revealed no changes, remaining within normal limits. Conclusion: Symptomatic load as well as blood pressures decreased on follow-up. CMR did not detect significant changes in tissue parameters; however, volumetric, specifically LV-SV, and deformation indexes improved during mid-term follow-up.

Catheter ablation of parahisian premature ventricular complexes in patients with and without cardiac scar.

BACKGROUND: Ablation of premature ventricular complexes (PVCs) originating from the parahisian area is challenging. Late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) scar may influence procedural outcomes; the impact of cardiac scar on parahisian PVCs has not been described. OBJECTIVE: The objective of this study was to examine the incidence and significance of LGE-CMR scarring in patients undergoing ablation for parahisian PVCs. METHODS: Consecutive patients who underwent preprocedure LGE-CMR imaging and ablation of parahisian PVCs were included. Acute and long-term outcomes were examined. RESULTS: Forty-eight patients were included (male, n = 37; age, 66 ± 10 years; ejection fraction, 50% ± 12%; preprocedure PVC burden, 21% ± 12%). Intramural LGE-CMR scar was present in 33 of 48 (69%) patients. Cryoablation was used in 9 patients; ablation in multiple chambers was required in 28 (58%) patients. The PVC site of origin (SOO) was intramural (n = 25 patients), left ventricular (n = 5), and right ventricular (n = 18). Patients with LGE-CMR scar were more likely to have intramural PVCs (64% vs 27%; P < .04) and to require ablation in multiple cardiac chambers (58% vs 13%; P < .02). Patients with intramural scar required longer duration of ablation delivery (31 ± 20 minutes vs 17 ± 8 minutes; P < .02). Acute procedural success was 69%; PVC burden on follow-up was 6% ± 9% and similar for those with and without scar. CONCLUSION: Ablation of parahisian PVCs often requires mapping and ablation of multiple cardiac chambers, with an intramural SOO identified in most patients. An intramural scar was associated with an intramural SOO of the PVCs requiring more extensive ablation procedures, with similar long-term outcomes compared with those without scar.