Enhancement Magnetic Resonance Imaging Research Articles

Digital Mammography (DM) vs. Dynamic Contrast Enhancement—Magnetic Resonance Imaging (DCE-MRI) in Microcalcifications Assessment: A Radiological–Pathological Comparison

The aim of this study was to compare the characteristics of breast microcalcification on digital mammography (DM) with the histological and molecular subtypes of breast cancer and to identify the predictive value of DM and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing microcalcifications for radiologic–pathologic correlation. We relied on our prospectively maintained database of suspicious microcalcifications on DM, from which data were retrospectively collected between January 2020 and April 2023. We enrolled 158 patients, all of whom were subjected to biopsy. Additionally, 63 patients underwent breast DCE-MRI. Microcalcifications with a linear branched morphology were correlated with malignancies (p < 0.001), among which an association was highlighted between triple negatives (TNs) and segmental distribution (p < 0.001). Amorphous calcifications were correlated with atypical ductal hyperplasia (ADH) (p = 0.013), coarse heterogeneous (p < 0.001), and fine-pleomorphic (p = 0.008) with atypical lobular hyperplasia (ALH) and fine pleomorphic (p = 0.009) with flat epithelial atypia (FEA). Regarding DCE-MRI, no statistical significance was observed between non-mass lesions and ductal carcinoma in situ (DCIS). Concerning mass lesions, three were identified as DCIS and five as invasive ductal carcinoma (IDC). In conclusion, microcalcifications assessed in DM exhibit promising predictive characteristics concerning breast lesion subtypes, leading to a reduction in diagnostic times and further examination costs, thereby enhancing the clinical management of patients.

Regional conduction velocities determined by noninvasive mapping are associated with arrhythmia-free survival after atrial fibrillation ablation

BackgroundAtrial arrhythmogenic substrate is a key determinant of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI), and reduced conduction velocities have been linked to adverse outcome. However, a noninvasive method to assess such electrophysiologic substrate is not available to date. ObjectiveThis study aimed to noninvasively assess regional conduction velocities and their association with arrhythmia-free survival after PVI. MethodsA consecutive 52 patients scheduled for AF ablation (PVI only) and 19 healthy controls were prospectively included and received electrocardiographic imaging (ECGi) to noninvasively determine regional atrial conduction velocities in sinus rhythm. A novel ECGi technology obviating the need of additional computed tomography or cardiac magnetic resonance imaging was applied and validated by invasive mapping. ResultsMean ECGi-determined atrial conduction velocities were significantly lower in AF patients than in healthy controls (1.45 ± 0.15 m/s vs 1.64 ± 0.15 m/s; P < .0001). Differences were particularly pronounced in a regional analysis considering only the segment with the lowest average conduction velocity in each patient (0.8 ± 0.22 m/s vs 1.08 ± 0.26 m/s; P < .0001). This average conduction velocity of the “slowest” segment was independently associated with arrhythmia recurrence and better discriminated between PVI responders and nonresponders than previously proposed predictors, including left atrial size and late gadolinium enhancement (magnetic resonance imaging). Patients without slow-conduction areas (mean conduction velocity <0.78 m/s) showed significantly higher 12-month arrhythmia-free survival than those with 1 or more slow-conduction areas (88.9% vs 48.0%; P = .002). ConclusionThis is the first study to investigate regional atrial conduction velocities noninvasively. The absence of ECGi-determined slow-conduction areas well discriminates PVI responders from nonresponders. Such noninvasive assessment of electrical arrhythmogenic substrate may guide treatment strategies and be a step toward personalized AF therapy.

Peptide radionuclide radiation therapy with Lutathera in multirecurrent nonanaplastic meningiomas: antitumoral activity study by growth rate analysis.

Several retrospective studies and meta-analyses of Peptide Radionuclide Radiation Therapy in meningiomas suggest six-month progression-free survival improvement for WHO grade 1 and 2 meningiomas. In the present study, we aimed to evaluate the impact of such treatment on three-dimensional volume growth rate (3DVGR) in nonanaplastic meningiomas. The authors performed a retrospective study including eight patients treated with Lutathera®. Millimetric 3D T1-weighted with gadolinium enhancement magnetic resonance imaging sequences were requested for volume measurement. Then, tumor growth rate was classified following a previously described 3DVGR classification (Graillon et al.). Patients harbored seven WHO grade 2 meningiomas and one aggressive WHO grade 1. All patients, except one, underwent four treatment cycles. 3DVGR significantly decreased at 3, 6, and 12 months after treatment initiation analyzing each lesion separately. Mean and median 3DVGR from all patients were respectively at 29.5% and 44.5%/6 months before treatment initiation, then at 16.5% and 25%/6 months at three months post-treatment initiation, 9.5% and 4.5%/6 months after 6 months, as well as 9.5% and 10.5%/6 months after 12 months. At 3, 6, and 12 months after treatment initiation, 4/8, 6/7, and 5/6 patients were class 2 (stabilization or severe 3DVGR slowdown), respectively. No patient was class 1 at 6 and 12 months, suggesting a lack of drug response. In nonanaplastic meningiomas, Lutathera®'s antitumoral activity appeared delayed and more likely observed at six months, while no major response was observed under treatment. Moreover, its antitumoral activity persisted for 12-18 months following treatment initiation.

Superfluorinated, Highly Water-Soluble Polyphosphazenes as Potential 19F Magnetic Resonance Imaging (MRI) Contrast Agents.

"Hot spot" 19F magnetic resonance imaging (MRI) has garnered significant attention recently for its ability to image various disease markers quantitatively. Unlike conventional gadolinium-based MRI contrast agents, which rely on proton signal modulation, 19F-MRI's direct detection has a unique advantage in vivo, as the human body exhibits a negligible background 19F-signal. However, existing perfluorocarbon (PFC) or PFC-based contrast materials suffer from several limitations, including low longitudinal relaxation rates and relatively low imaging efficiency. Hence, we designed a macromolecular contrast agent featuring a high number of magnetically equivalent 19F-nuclei in a single macromolecule, adequate fluorine nucleus mobility, and excellent water solubility. This design utilizes superfluorinated polyphosphazene (PPz) polymers as the 19F-source; these are modified with sodium mercaptoethanesulfonate (MESNa) to achieve water solubility exceeding 360 mg/mL, which is a similar solubility to that of sodium chloride. We observed substantial signal enhancement in MRI with these novel macromolecular carriers compared to non-enhanced surroundings and aqueous trifluoroacetic acid (TFA) used as a positive control. In conclusion, these novel water-soluble macromolecular carriers represent a promising platform for future MRI contrast agents.

Combined Orbital and Cranial Vessel Wall Magnetic Resonance Imaging for the Assessment of Disease Activity in Giant Cell Arteritis.

Acute visual impairment is the most feared complication of giant cell arteritis (GCA) but is challenging to predict. Magnetic resonance imaging (MRI) evaluates orbital pathology not visualized by an ophthalmologic examination. This study combined orbital and cranial vessel wall MRI to assess both orbital and cranial disease activity in patients with GCA, including patients without visual symptoms. Patients with suspected active GCA who underwent orbital and cranial vessel wall MRI were included. In 14 patients, repeat imaging over 12 months assessed sensitivity to change. Clinical diagnosis of ocular or nonocular GCA was determined by a rheumatologist and/or ophthalmologist. A radiologist masked to clinical data scored MRI enhancement of structures. Sixty-four patients with suspected GCA were included: 25 (39%) received a clinical diagnosis of GCA, including 12 (19%) with ocular GCA. Orbital MRI enhancement was observed in 83% of patients with ocular GCA, 38% of patients with nonocular GCA, and 5% of patients with non-GCA. MRI had strong diagnostic performance for both any GCA and ocular GCA. Combining MRI with a funduscopic examination reached 100% sensitivity for ocular GCA. MRI enhancement significantly decreased after treatment (P < 0.01). In GCA, MRI is a sensitive tool that comprehensively evaluates multiple cranial structures, including the orbits, which are the most concerning site of pathology. Orbital enhancement in patients without visual symptoms suggests that MRI may detect at-risk subclinical ocular disease in GCA. MRI scores decreased following treatment, suggesting scores reflect inflammation. Future studies are needed to determine if MRI can identify patients at low risk for blindness who may receive less glucocorticoid therapy.

Predicting cerebral glioma enhancement pattern using a machine learning-based magnetic resonance imaging radiomics model

To establish a machine learning radiomics model that can accurately predict MRI enhancement patterns of glioma based on T2 fluid attenuated inversion recovery (T2-FLAIR) images for optimizing the workflow of magnetic resonance imaging (MRI) examinations of glioma patients. We retrospectively collected preoperative MR T2-FLAIR images from 385 patients with pathologically confirmed glioma, who were divided into enhancing and non-enhancing groups according to the enhancement pattern. Predictive radiomics models were established using Gaussian Process, Linear Regression, Linear Regression-Least absolute shrinkage and selection operator, Support Vector Machine, Linear Discriminant Analysis or Naive Bayes as the classifiers in the training cohort (n=201)and tested both in the internal (n=85) and external validation cohorts (n=99). The receiver-operating characteristic curve was used to assess the predictive performance of the models. The predictive model constructed based on 15 radiomics features using Gaussian Process as the classifier had the best predictive performance in both the training cohort and the internal validation cohort, with areas under the curve (AUC) of 0.88 (95% CI: 0.81-0.94) and 0.80 (95% CI: 0.71-0.88), respectively. In the external validation cohort, the model showed an AUC of 0.81 (95% CI: 0.71-0.90) with sensitivity, specificity, positive predictive value and negative predictive value of 0.98, 0.61, 0.76 and 0.96, respectively. The T2-FLAIR-based machine learning radiomics model can accurately predict the enhancement pattern of gliomas on MRI.

A 3-hour time interval may not be sufficient for delayed enhancement magnetic resonance imaging with intravenous gadoteridol injection based on 3d-real IR sequence of the inner ear in Meniere’s disease patient

Background Magnetic resonance imaging (MRI) can be applied to visualize endolymphatic hydrops (EH). Aims/Objectives To explore whether a 3-h time interval was feasible for clinical practice. Materials and methods We prospectively enrolled 15 patients with unilateral Meniere’s disease, each of whom underwent delayed enhancement MRI scan of the inner ear after intravenous gadoteridol injection at a 3-h interval. The ears of these patients were divided into two groups (group A: the affected ears; group B: the unaffected ears). Among the two groups, the signal intensity in perilymphatic area of the basal turn of cochlea, the results of visual evaluations in the vestibule, cochlea and semicircular canal and the detection results of EH were compared. Results Regarding the signal intensity, a difference was found between group A and group B (p = .016). Besides, no difference was found between the visual evaluations in the vestibule, cochlea and semicircular canal of the two groups. Regarding the detection results of EH, group A (6 vestibules were undiagnosable; 8 cochleae were undiagnosable); group B (9 vestibules were undiagnosable; 10 cochleae were undiagnosable). Conclusions and significance In the clinical application of gadoteridol for the inner ear, 3-h delayed MR imaging may not be sufficient.

Multimodality Imaging in Cranial Giant Cell Arteritis: First Experience with High-Resolution T1-Weighted 3D Black Blood without Contrast Enhancement Magnetic Resonance Imaging.

In order to support or refute the clinical suspicion of cranial giant cell arteritis (GCA), a supplemental imaging modality is often required. High-resolution black blood Magnetic Resonance Imaging (BB MRI) techniques with contrast enhancement can visualize artery wall inflammation in GCA. We compared findings on BB MRI without contrast enhancement with findings on 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/low-dose computed tomography (2-[18F]FDG PET/CT) in ten patients suspected of having GCA and in five control subjects who had a 2-[18F]FDG PET/CT performed as a routine control for malignant melanoma. BB MRI was consistent with 2-[18F]FDG PET/CT in 10 out of 10 cases in the group with suspected GCA. In four out of five cases in the control group, the BB MRI was consistent with 2-[18F]FDG PET/CT. In this small population, BB MRI without contrast enhancement shows promising performance in the diagnosis of GCA, and might be an applicable imaging modality in patients.

Self-supervised MRI denoising: leveraging Stein’s unbiased risk estimator and spatially resolved noise maps

Thermal noise caused by the imaged object is an intrinsic limitation in magnetic resonance imaging (MRI), resulting in an impaired clinical value of the acquisitions. Recently, deep learning (DL)-based denoising methods achieved promising results by extracting complex feature representations from large data sets. Most approaches are trained in a supervised manner by directly mapping noisy to noise-free ground-truth data and, therefore, require extensive paired data sets, which can be expensive or infeasible to obtain for medical imaging applications. In this work, a DL-based denoising approach is investigated which operates on complex-valued reconstructed magnetic resonance (MR) images without noise-free target data. An extension of Stein’s unbiased risk estimator (SURE) and spatially resolved noise maps quantifying the noise level with pixel accuracy were employed during the training process. Competitive denoising performance was achieved compared to supervised training with mean squared error (MSE) despite optimizing the model without noise-free target images. The proposed DL-based method can be applied for MR image enhancement without requiring noise-free target data for training. Integrating the noise maps as an additional input channel further enables the regulation of the desired level of denoising to adjust to the preference of the radiologist.

FK-means: automatic atrial fibrosis segmentation using fractal-guided K-means clustering with Voronoi-clipping feature extraction of anatomical structures.

Assessment of left atrial (LA) fibrosis from late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) adds to the management of patients with atrial fibrillation. However, accurate assessment of fibrosis in the LA wall remains challenging. Excluding anatomical structures in the LA proximity using clipping techniques can reduce misclassification of LA fibrosis. A novel FK-means approach for combined automatic clipping and automatic fibrosis segmentation was developed. This approach combines a feature-based Voronoi diagram with a hierarchical 3D K-means fractal-based method. The proposed automatic Voronoi clipping method was applied on LGE-MRI data and achieved a Dice score of 0.75, similar to the score obtained by a deep learning method (3D UNet) for clipping (0.74). The automatic fibrosis segmentation method, which uses the Voronoi clipping method, achieved a Dice score of 0.76. This outperformed a 3D UNet method for clipping and fibrosis classification, which had a Dice score of 0.69. Moreover, the proposed automatic fibrosis segmentation method achieved a Dice score of 0.90, using manual clipping of anatomical structures. The findings suggest that the automatic FK-means analysis approach enables reliable LA fibrosis segmentation and that clipping of anatomical structures in the atrial proximity can add to the assessment of atrial fibrosis.

Nanodiamond-Enhanced Magnetic Resonance Imaging.

Nanodiamonds (ND) hold great potential for diverse applications due to their biocompatibility, non-toxicity, and versatile functionalization. Direct visualization of ND by means of non-invasive imaging techniques will open new venues for labeling and tracking, offering unprecedented and unambiguous detection of labeled cells or nanodiamond-based drug carrier systems. The structural defects in diamonds, such as vacancies, can have paramagnetic properties and potentially act as contrast agents in magnetic resonance imaging (MRI). The smallest nanoscale diamond particles, detonation ND, are reported to effectively reduce longitudinal relaxation time T1 and provide signal enhancement in MRI. Using in vivo, chicken embryos, direct visualization of ND is demonstrated as a bright signal with high contrast to noise ratio. At 24 h following intravascular application marked signal enhancement is noticed in the liver and the kidneys, suggesting uptake by the phagocytic cells of the reticuloendothelial system (RES), and in vivo labeling of these cells. This is confirmed by visualization of nanodiamond-labeled macrophages as positive (bright) signal, in vitro. Macrophage cell labeling is not associated with significant increase in pro-inflammatory cytokines or marked cytotoxicity. These results indicate nanodiamond as a novel gadolinium-free contrast-enhancing agent with potential for cell labeling and tracking and over periods of time.

NCMP-02. BIOPSY OUTCOMES OF PATIENTS WITH SUSPECTED LEPTOMENINGEAL CARCINOMATOSIS: A RETROSPECTIVE CASE SERIES

Abstract BACKGROUND Leptomeningeal carcinomatosis is commonly considered when patients present with meningeal enhancement on magnetic resonance imaging (MRI), even without a known primary malignancy. In practice, some clinicians advocate for early meningeal biopsy to expedite diagnosis, citing lack of specificity of other testing, such as cerebrospinal fluid (CSF) analysis. METHODS We identified a cohort of patients with meningeal enhancement that underwent biopsy for diagnostic purposes between 2010 and 2022. Presenting symptoms, physical exam, enhancement pattern on MRI, other imaging findings, CSF parameters, other laboratory results, final diagnosis, and recommended treatment were recorded when available. RESULTS Out of nearly 100 cases included, the majority were autoimmune or inflammatory in etiology. Only 13 patients were diagnosed with malignancy-related enhancement, and 10 of these cases were felt to be true carcinomatosis. Nine out of the 13 patients were diagnosed with lymphoma. Four of these lymphomas were diagnosed on systemic biopsy, with meningeal biopsies negative for malignant cells. The other malignancies included systemic adenocarcinoma, oligodendroglioma, and a rare hematologic cancer. Nearly all 13 patients had abnormal CSF parameters, notably pleocytosis, but none had malignant cells in the fluid. Most frequent presenting symptoms were encephalopathy, vision changes, and strength/sensory changes. MRI often showed cranial nerve or general cerebral and cerebellar involvement, and physical exam often showed cranial nerve, strength, and sensory deficits. All patients proceeded with chemotherapy after diagnosis. CONCLUSIONS When leptomeningeal carcinomatosis is considered based on MRI enhancement, the clinical approach should continue to revolve around indirect testing such as CSF analysis, serum studies, and other imaging techniques to consider alternative biopsy sites before pursuing direct sampling with meningeal biopsy. With this approach, many patients with suspected carcinomatosis can avoid undergoing meningeal biopsy and decrease the chance of treatment delay.

The benefit of a double ventricular extra stimuli protocol to improve functional substrate mapping during ablation of ventricular tachycardia. - The S3-VT-FREE project

Abstract Introduction Ablation of ventricular tachycardia (VT) based on substrate-based mapping has been proposed to itemize areas of interest identifying areas of low-voltage, late potentials (LPs), and deceleration zones (DZs). However, partial delineation of targets for ablation is likely responsible for a suboptimal long-term success rate. The abnormal electrograms (EGMs), featuring low-voltage near-field components may be hidden within the high-amplitude far-field signal. We hypothesized that the acquisition of functional mapping after double ventricular extrastimuli (S3 protocol) would uncover relevant areas of functional substrate that could be missed during sinus or S1 map. We aim to evaluate the potential benefit and the feasibility of functional substrate mapping using an S3 protocol for VT ablation and to assess its colocalization with detected corridors using late gadolinium enhancement magnetic resonance imaging (LGE-MRI). Methods We included consecutively 29 patients with structural cardiomypathy who underwent a VT ablation. The S3 protocol included: (1) assessment of the ventricular effective refractory period (ERP), (2) pacing protocol from the apex of the right ventricle with S1 x 6 (cycle length: 600ms) followed by S2 (ERP+30ms) and S3 (ERP+50ms). Electroanatomical mapping was acquired with the EnsiteX system (Abbott, IL) using HD Grid catheter and omnipolar signals. ILAMs were used to identify deceleration zones and areas of late potentials were identified for all maps. A non-invasive substrate assessment was done with LGE-MRI and post-processing with a commercially available system (ADAS3D, Spain) with automated identification of corridors. Results The S3 protocol was completed in 25 of the 29 procedures (86.2%). The repeated induction of ventricular arrhythmias did not allow for full protocol of the S3 protocol in 4 patients (13.8%). The functional substrate identified during the S3 activation mapping was significantly more extensive than the one identified using S1 and S2 activation mappings (p&amp;lt;0.05) (Table). The S3 protocol unmasked a higher number of DZs (p&amp;lt;0.01), a wider area of LPs (p&amp;lt;0.01), and a longer duration of the DZs (p=0.01). All DZ maps were compared with preprocedural cardiac magnetic resonance. The number of DZs matching with conduction corridors identified by LGE-MRI was higher in the activation mapping of S3 compared with the S1 and S2 ones (p=0.02). After VT ablation based on an S3 protocol, 88% of patients have been VT free during a median follow-up of 9 months. Conclusions This novel substrate-based protocol to assess the ventricular functional substrate is feasible in the majority of patients (86.2%) and allows for a better identification of targets for ablation and could facilitate VT ablation, and improve the prognosis of the patients after ablation.

Abstract 12357: Investigating Sex-Specific Factors Influencing Atrial Fibrillation Burden in Patients With Persistent Atrial Fibrillation: A DECAAF II Subanalysis

Background: Atrial Fibrillation(AF) burden provides insights beyond the common binary classification of AF recurrence after catheter ablation(CA). Objective: We sought to investigate the predictors of AF burden in patients with persistent AF(PeAF) at 1 year post-CA, with a focus on sex-based differences. The analysis was conducted separately for both female and male. Methods: We examined all PeAF patients in the DECAAF II trial and divided them into 2 groups, women and men. Baseline demographics and late gadolinium enhancement magnetic resonance imaging data were reviewed. Patients were instructed to provide single-lead home ECG strips once daily. AF burden was calculated by dividing the total number of days in AF over the total number of days when strips were sent. Univariate and multivariate analysis were performed to predict AF burden beyond the 3-month blanking period. Results: We included 658 patients(20% Female,80% male) who transmitted 215825 ECG strips. The average AF burden across the population was 17%. The mean AF burden was higher in women(21%) than in men(16%)(p&lt;0.01). In women, on univariate analysis, baseline fibrosis(p&lt;0.05), history of stroke(p&lt;0.01) and left atrial(LA) volume(p&lt;0.01) were positively correlated with AF burden. After conducting a multivariate analysis, we found that baseline fibrosis(p&lt;0.05), history of stroke(p&lt;0.05), vascular diseases(p&lt;0.05), and LA volume(p&lt;0.01) were independent predictors of AF burden. In men, on univariate analysis, age(p&lt;0.01), baseline fibrosis(p&lt;0.01), hyperlipidemia(p&lt;0.01) and LA volume(p&lt;0.01) were positively correlated with AF burden. After conducting a multivariate analysis, only LA volume (p&lt;0.01) and age(&lt;0.01) continued to be significantly related(Table 1). Conclusion: Sex-specific management strategies are crucial for addressing AF, as our study demonstrates a significant impact of sex on predicting AF burden monitored by a single-lead handheld smartphone ECG device.

Abstract 18093: History of Stroke as a Predictor of High Left Atrial Fibrosis in Patients With Persistent Atrial Fibrillation

Introduction: The relationship between left atrial (LA) remodeling and ischemic stroke (IS) risk in patients with atrial fibrillation (AF) is well-established. The DECAAF II trial is the largest MRI-based, multicenter, randomized study conducted on persistent AF patients. Hypothesis: Our research investigates whether a history of stroke correlates with the extent of atrial fibrosis, as determined by late gadolinium enhancement magnetic resonance imaging (LGE-MRI), among the DECAAF II trial population. Methods: Patients with persistent AF who underwent LGE-MRI were enrolled and categorized into two cohorts: those with a history of stroke and those without. Covariates were adjusted using propensity score matching, and atrial fibrosis was compared between groups. Participants were then subdivided according to three baseline atrial fibrosis cut-off values: ≥ 15%, ≥ 20%, ≥ 25%. Univariate logistic regression and adjusted multivariate analyses were applied to evaluate the impact of clinical characteristics and risk factors on baseline fibrosis. Results: From the 843 patients involved in the DECAAF II trial, 70 (8.3%) had a stroke history. Those with stroke history had higher rates of hypertension, diabetes, and hyperlipidemia. Seventy patients without a stroke history were matched to stroke patients using propensity score analysis, revealing a significantly higher fibrosis in the stroke group (20.2% vs. 8.1%, p = 0.017). Increasing age significantly predicted all three baseline fibrosis categories (≥15%, ≥20%, ≥25%). Notably, stroke history was as a predictor of baseline fibrosis ≥25%, even after adjusting for other risk factors and clinical characteristics (OR = 1.98 [1.14-3.43], p = 0.01). Conclusions: There is a significant correlation between high left atrial fibrosis level and an increased risk of ischemic stroke in patients with persistent atrial fibrillation. This suggests that atrial fibrosis may provide insights into stroke risk classification.

Abstract 19134: Association Between CHA 2 DS 2 -VASc and LA Volume Index: Insights From DECAAF II

Introduction: LA Volume is strongly associated with atrial fibrillation (AF) and underlying atrial myopathy. The CHA 2 DS 2 -VASc score predicts stroke risk in patients with AF. The aim of this study is to investigate the relationship between the two. Methods: In this subanalysis of the DECAAF II trial, patients with persistent AF undergoing first-time catheter ablation underwent a baseline late gadolinium enhancement magnetic resonance imaging (LGE-MRI) within one month prior to ablation. LA Volume Index (LAVI) was defined as LA Volume on the MRI prior to ablation divided by body surface area ( mL/m2 ). The CHA2 DS2 -VASc score was also calculated at baseline prior to ablation. Analysis of Variance (ANOVA) test and linear regression were used to study the association between the two. Results: 815 patients were included, (78.9% males, mean age 62.7 ± 9.1 years) (table). The mean LAVI was 62.2 ± 18.9 mL/m2, and mean CHA2 DS2 -VASc score was 1.7 ± 1.27. The ANOVA test showed significant differences between group (F = 7.71, p &lt;0.001). For every point increase in CHA2 DS2 -VASc score, LAVI increases by 3 (LAVI = 2.99 * CHA2 DS2 -VASc + 57; p &lt;0.001) (figure). Conclusions: Our data suggests that structural remodeling in patients with AF is likely driven by multiple factors. There was a clear association between CHA2 DS2 -VASc score and higher LAVI. Serial analysis of LA Volume at different time points is needed to further understand the impact of individual comorbidities on LA volume dilation.

An Investigation Into Whether the Facial Nerve and Auditory Nerve can be Protected by Removal of the Posterior Wall of the Internal Auditory Canal Under 30° Neuroendoscopy During Vestibular Schwannoma Surgery.

The aim of this study was to evaluate the surgical technique of microresection of vestibular schwannoma by removing the posterior wall of the internal auditory canal (IAC) under neuroelectrophysiological monitoring and 30° neuroendoscopy, with respect to the protection of facial and auditory nerve function. Forty-five cases of microscopic resection of auditory neuromas were performed through a posterior approach to the inferior occipital sigmoid sinus using a 30° neuroendoscope to assist in the removal of the posterior wall of the IAC during surgery. Patients underwent cranial enhancement magnetic resonance imaging examination and functional assessment of the facial and auditory nerves before and after surgery, and clinical data were collected for retrospective analysis. All tumors were removed in 41 patients, and most of the tumors were removed in 4 patients. The facial nerve was anatomically preserved in 43 patients (95.6%), and the percentage of facial nerve function preservation (House-Brackmann grade I-II) was 84.4%. Forty patients (88.9%) had anatomical preservation of the auditory nerve, with a 66.7% functional preservation rate. At 3 to 39 months of follow-up, 45 patients were reviewed with 3.0T-enhanced magnetic resonance imaging, and no tumor recurrence was observed in any of the patients. Microscopic resection of auditory neuroma through the posterior approach of the inferior occipital sigmoid sinus with intraoperative use of 30° neuroendoscopic assistance to abrade the posterior wall of the IAC can eliminate dead space in certain anatomical areas during surgery and minimize surgical damage to the facial and auditory nerves, which is the basis for preservation of facial and auditory nerve function.

Adult Intramedullary Mature Teratoma of the Spinal Cord: An Unusual Case with a Review of the Literature

Intraspinal teratoma is a rare subtype of spinal cord tumors, accounting for only 0.2% to 0.5% of cases. These tumors consist of a mixture of two or more germ cell layers, including the ectoderm, endoderm, and mesoderm. They often contain epithelial tissues, fatty tissues, and follicles derived from these three layers, which can be visualized on magnetic resonance imaging (MRI) in most cases. However, in our patient, a 35-year-old woman with an intradural oval intramedullary teratoma at the L4 level, the tumor exhibited features similar to those of a schwannoma. On MRI, the tumor appeared as a 2-cm mass attached to the end of the spinal cord, with intermediate signal intensity on T2-weighted images and iso-intensity without enhancement on T1-weighted images. L4 laminoplasty with tumor removal was performed under intraoperative monitoring. The tumor was found to be firm with a cyst containing mucoid and fatty tissue posteriorly. Near-total resection was achieved, although the tumor margin was indistinct. A literature review revealed spinal cord tethering and the presence of fatty tissue without MRI enhancement as characteristic findings of teratomas and dermoid cysts.

Expression of clMagR/clCry4 protein in mBMSCs provides T2-contrast enhancement of MRI

Here, we propose for the first time the evaluation of magnetosensitive clMagR/clCry4 as a magnetic resonance imaging (MRI) reporter gene that imparts sensitivity to endogenous contrast in eukaryotic organisms. Using a lentiviral vector, we introduced clMagR/clCry4 into C57BL/6 mice-derived bone marrow mesenchymal stem cells (mBMSCs), which could specifically bind with iron, significantly affected MRI transverse relaxation, and generated readily detectable contrast without adverse effects in vivo. Specifically, clMagR/clCry4 makes mBMSCs beneficial for enhancing the sensitivity of MRI-R2 for iron-bearing granules, in which cells recruit exogenous iron and convert these stores into an MRI-detectable contrast; this is not achievable with control cells. Additionally, Prussian blue staining was performed together with ultrathin cell slices to provide direct evidence of natural iron-bearing granules being detectable on MRI. Hence, it was inferred that the sensitivity of MRI detection should be correlated with clMagR/clCry4 and exogenous iron. Taken together, the clMagR/clCry4 has great potential as an MRI reporter gene. Statement of significanceIn this study, we propose the evaluation of magnetosensitive clMagR/clCry4 as an MRI reporter gene, imparting detection sensitivity to eukaryotic mBMSCs for endogenous contrast. At this point, the clMagR and clCry4 were located within the cytoplasm and possibly influence each other. The clMagR/clCry4 makes mBMSCs beneficial for enhancing the sensitivity of MRI-R2 for iron-bearing granules, in which protein could specifically bind with iron and convert these stores into MRI-detectable contrast; this is not achieved by control cells. The viewpoint was speculated that the clMagR/clCry4 and exogenous iron were complementary to each other. Additionally, Prussian blue staining was performed together with TEM observations to provide direct evidence that the iron-bearing granules were sensitive to MRI.

The Effectiveness of Ablation Therapy for Atrial Fibrillation: A Systematic Review.

It is expected that the prevalence of atrial fibrillation (AF), the most prevalent cardiac arrhythmia among people aged 65 to 85, would be mostly classified using the CHAS2DS2-VASc approach for anticoagulation therapy. A high number of people in the entire world will be living with AF by 2030. Long-term follow-up data are sparse, although radiofrequency catheter ablation (CA) for symptomatic AF patients has the potential to be a curative therapy. Although women are referred later and less often than men, the outcomes following ablation are comparable across both genders. Health-related quality of life suffers from AF, and patients often find themselves less active as a result of their condition. AF may have a wide variety of symptoms and signs from the clinic's point of view. Women are more likely to exhibit symptoms than men; one reason for this is that women have an average QT interval that is 10-20 milliseconds longer than men, which is more likely to exacerbate tachycardia symptoms. In search of medical databases for relevant medical literature, we looked at PubMed/Medline, the Cochrane Library, and Google Scholar. Ten publications were gathered after the papers were located, assessed, and qualifying criteria applied were used to select them. The finished articles were done to give an overview of the effectiveness of ablation therapy for AF. Some studies showed that there was no statistical significance between invasive and pharmacological treatments. Other research found no difference in the recurrence of atrial arrhythmia between pulmonary vein isolation (PVI) CA alone and PVI + enhancement magnetic resonance imaging (MRI)-guided fibrosis ablation in individuals with persistent AF. The oldest individuals in studies comparing CA to medical treatment for AF demonstrated no improvement in prognosis after CA. Also, complications from therapy and CA's efficacy in preventing future atrial arrhythmias were similarly low across all age groups. Based on the above, we concluded that more studies are required to establish the most effective approach to treating AFto apply it in daily practice and gain more knowledge about it.