RESUMEN

Episodic memory is essential for forming and retaining personal experiences, representing a fundamental aspect of human cognition. Traditional studies of episodic memory have typically used static analysis methods, viewing the brain as an unchanging entity and overlooking its dynamic properties over time. In this study, we utilized dynamic functional connectivity analysis on fMRI data from healthy adults performing an episodic memory task. We quantified integration and recruitment metrics and examined their correlation with memory performance using Pearson correlation. During encoding, integration across the entire brain, especially within the frontoparietal subnetwork, was significantly correlated with memory performance. During retrieval, recruitment becomes significantly associated with memory performance in visual subnetwork, somatomotor subnetwork, and ventral attention subnetwork. At the nodal level, a significant negative correlation was observed between memory scores and integration of the anterior cingulate gyrus, precentral gyrus, and inferior frontal gyrus within the frontoparietal network during encoding task. During retrieval task, a significant negative correlation was found between memory scores and recruitment in the left progranular cortex and right transverse gyral ventral, whereas positive correlations were seen in the right posterior inferior temporal, left middle temporal, right frontal operculum, and left operculum nodes. Moreover, the dynamic reconfiguration of the functional network was predictive of predict memory performance, as demonstrated by a significant correlation between actual and predicted memory scores. These findings advance our understanding network mechanisms underlying memory processes and developing intervention approaches for memory-related disorders as they shed light on critical factors involved in cognitive processes and provide a deeper understanding of the underlying mechanisms driving cognitive function.

Asunto(s)

RESUMEN

Seizure following cerebrospinal fluid (CSF) rhinorrhoea surgery or surgery of the skull base almost always implies postoperative meningoencephalitis, unless proven otherwise. Here, we present the case of a middle-aged female in her 40's who underwent surgical CSF fistula closure and developed seizure on the eighth postoperative day. She was diagnosed to have posterior reversible encephalopathy syndrome (PRES). Early diagnosis and prompt initiation of treatment ensured that she had a complete recovery. Although not reported in the literature, PRES should always be a differential diagnosis in such situations, as delay in diagnosis may result in significant morbidity and rarely mortality.

Asunto(s)

RESUMEN

The narrative review article is focused on the strengths and limitations of modern imaging methods in the preoperative differential diagnosis of uterine mesenchymal tumours. In order to tailor the surgical procedures, imaging methods, namely ultrasound and magnetic resonance imaging (MRI), should be taken into account as well as clinical symptoms, age, and fertility plans. On ultrasound scans, uterine sarcomas have the appearance of large, usually solitary tumours of non-homogenous structure with irregular cysts, ill-defined outline borders (interrupted capsule), absence of calcifications with acoustic shadowing, and moderate to rich internal vascularisation. Rapid growth between follow-ups or atypical growth in peri- or post-menopause is also a sign of malignancy. On MRI, uterine sarcomas are characterized by irregular borders, hyperintense areas on T1-weighted and T2- weighted images, and central non-enhancing necrotic areas. On diffusion-weighted imaging (DWI/MRI), sarcomas exhibit markedly restricted diffusion but there is a significant overlap with some variants of fibroids. Core-needle or hysteroscopic biopsy can be used preoperatively if suspicious features are detected on ultrasound or MRI scans, particularly before myomectomy if fertility preservation is required or when conservative management is considered in asymptomatic women. Other imaging methods, such as positron emission tomography fused with CT (PET-CT) or computed tomography (CT) have limited role to distinguish uterine sarcomas from myomas and are suitable only for staging purposes. The importance of tumour markers including lactate dehydrogenase in preoperative work-up have not been verified yet. Conclusion: Uterine sarcomas can be distinguished from much more common myomas based on a combination of malignant features on ultrasound or MR imaging. In these suspicious cases the type and extent of surgery should be adjusted, avoiding intraperitoneal morcellation, which could lead to iatrogenic tumour spread and worsening of the patient's prognosis.

Asunto(s)

RESUMEN

Adolescence is a period of substantial social-emotional development, accompanied by dramatic changes to brain structure and function. Social isolation due to lockdowns that were imposed because of the COVID-19 pandemic had a detrimental impact on adolescent mental health, with the mental health of females more affected than males. We assessed the impact of the COVID-19 pandemic lockdowns on adolescent brain structure with a focus on sex differences. We collected MRI structural data longitudinally from adolescents prior to and after the pandemic lockdowns. The pre-COVID data were used to create a normative model of cortical thickness change with age during typical adolescent development. Cortical thickness values in the post-COVID data were compared to this normative model. The analysis revealed accelerated cortical thinning in the post-COVID brain, which was more widespread throughout the brain and greater in magnitude in females than in males. When measured in terms of equivalent years of development, the mean acceleration was found to be 4.2 y in females and 1.4 y in males. Accelerated brain maturation as a result of chronic stress or adversity during development has been well documented. These findings suggest that the lifestyle disruptions associated with the COVID-19 pandemic lockdowns caused changes in brain biology and had a more severe impact on the female than the male brain.

Asunto(s)

Asunto(s)

RESUMEN

Several characteristic radiographic signs associated with various diseases are useful in neuroradiological practice; however, their clinical usefulness varies widely. This article presents some common signs and the associated pathological features, particularly those observed on computed tomography and magnetic resonance imaging or pathognomonic signs that are useful for accurate diagnosis, even in patients with rare diseases.

Asunto(s)

RESUMEN

BACKGROUND: Little is known about the underlying factors contributing to unfavourable clinical outcomes in patients with diabetes mellitus (DM) complicated by new-onset acute myocardial infarction (AMI). The aim of this study was to investigate the impact of DM on the pathophysiologic features and prognosis of patients with new-onset AMI following successful revascularization by utilizing cardiac magnetic resonance (CMR). METHODS: Consecutive patients diagnosed with new-onset AMI between June 2022 and January 2024 were included. All patients underwent culprit vessel revascularization upon admission and CMR imaging 3-7 days later. The primary clinical endpoint of this study was the occurrence of major adverse cardiac and cerebrovascular events (MACCEs), for which the average follow-up was 10 months. RESULTS: A total of 72 patients were divided into a DM group (n = 23) and a non-DM group (n = 49). Multivariate logistic regression analysis revealed that DM was an independent risk factor for the occurrence of microvascular obstruction. Multivariate linear regression analysis found that DM was the influencing factor of global radial strain (B = -4.107, t = -2.328, p = 0.023), while fasting blood glucose influenced infarct segment myocardial radial strain (B = -0.622, t = -2.032, p = 0.046). DM independently contributed to the risk of MACCEs following successful revascularization in patients with AMI (p < 0.05). CONCLUSION: Comprehensive phenotypic characterization of myocardial injury and microcirculatory status could enable reliable identification of high-risk MACCEs in DM patients with new-onset AMI following successful revascularization.

Asunto(s)

Asunto(s)

RESUMEN

BACKGROUND: A consensus definition for active sacroiliitis by MRI, mentioned in the Assessment of SpondyloArthritis International Society (ASAS) classification criteria for axial spondyloarthritis (axSpA), was published in 2009 and included a qualitative and quantitative MRI cut-off component. In 2021, updates to the quantitative component were preliminarily proposed. This post hoc analysis of part A of the phase 3 open-label C-OPTIMISE study (NCT02505542) explores the differences by applying the 2009 and preliminary 2021 inflammatory cut-offs on clinical outcomes of axSpA patients treated with certolizumab pegol. METHODS: Baseline MRI scans were used to classify 657 patients as MRI+ or MRI- according to the quantitative components of the 2009 and preliminary 2021 MRI cut-offs for inflammatory lesions. Clinical outcomes, including ASAS ≥40% improvement (ASAS40), Ankylosing Spondylitis Disease Activity Score and Bath Ankylosing Spondylitis Disease Activity Index, were reported to week 48. RESULTS: Across all analysed outcomes, 2009 MRI+ and preliminary 2021 MRI+ subgroups showed similar results. Notably, clinical outcomes for the discordant group (2009 MRI+but preliminary 2021 MRI- group; 53/657 [8.1%]) were close to those seen in MRI- patients according to either 2009 or preliminary 2021 inflammatory cut-offs, and notably different from the totality of MRI+ subgroups. CONCLUSION: This analysis suggests that the preliminary 2021 cut-offs for MRI inflammatory lesions may slightly increase the specificity of the quantitative part of the 2009 MRI inflammatory lesion definition. The effects of the updated MRI cut-offs need to be assessed on the basis of efficacy outcomes and with the inclusion of aspects of structural changes. TRIAL REGISTRATION NUMBER: NCT02505542.

Asunto(s)

RESUMEN

The relationship between structural changes in the cerebral gray matter and diminished balance control performance in patients with chronic ankle instability (CAI) has remained unclear. This paper aimed to assess the difference in gray matter volume (GMV) between participants with CAI and healthy controls (HC) and to characterize the role of GMV in the relationship between disease duration and balance performance in CAI. 42 participants with CAI and 33 HC completed the structural brain MRI scans, one-legged standing test, and Y-balance test. Regional GMV was measured by applying voxel-based morphometry methods. The result showed that, compared with HC, participants with CAI exhibited lower GMV in multiple brain regions (familywise error [FWE] corrected p < 0.021). Within CAI only, but not in HC, lower GMV in the thalamus (ß = -0.53, p = 0.003) and hippocampus (ß = -0.57, p = 0.001) was associated with faster sway velocity of the center of pressure (CoP) in eyes closed condition (i.e., worse balance control performance). The GMV in the thalamus (percentage mediated [PM] = 32.02%; indirect effect ß = 0.119, 95% CI = 0.003 to 0.282) and hippocampus (PM = 33.71%; indirect effect ß = 0.122, 95% CI = 0.005 to 0.278) significantly mediated the association between the disease duration and balance performance. These findings suggest that the structural characteristics of the supraspinal elements is critical to the maintenance of balance control performance in individuals suffering from CAI, which deserve careful consideration in the management and rehabilitation programs in this population.

Asunto(s)

RESUMEN

Total ankle arthroplasty (TAA) is an effective alternative for treating patients with end-stage ankle degeneration, improving mobility, and providing pain relief. Implant survivorship is constantly improving; however, complications occur. Many causes of pain and dysfunction after total ankle arthroplasty can be diagnosed accurately with clinical examination, laboratory, radiography, and computer tomography. However, when there are no or inconclusive imaging findings, magnetic resonance imaging (MRI) is highly accurate in identifying and characterizing bone resorption, osteolysis, infection, osseous stress reactions, nondisplaced fractures, polyethylene damage, nerve injuries and neuropathies, as well as tendon and ligament tears. Multiple vendors offer effective, clinically available MRI techniques for metal artifact reduction MRI of total ankle arthroplasty. This article reviews the MRI appearances of common TAA implant systems, clinically available techniques and protocols for metal artifact reduction MRI of TAA implants, and the MRI appearances of a broad spectrum of TAA-related complications.

Asunto(s)

RESUMEN

The gold standard diagnostic imaging tool for ankle OCLs is magnetic resonance imaging, which allows precise evaluation of the articular cartilage and assessment of the surrounding soft tissue structures. Post-operative morphologic MRI assessment via MOCART scores provide semi-quantitative analysis of the repair tissue, but mixed evidence exists regarding its association with post-operative outcomes. Post-operative biochemical MRIs allow assessment of the collagen network of the articular cartilage via T2-mapping and T2∗ mapping, and assessment of the articular glycosaminoglycan content via delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho mapping and sodium imaging.

Asunto(s)

RESUMEN

Radiography is considered the first-line screening exam for clinically suspected osteomyelitis. However, additional evaluation is generally needed. MRI is the definitive diagnostic exam with high sensitivity and specificity combined with excellent anatomic definition. Gadolinium contrast can be useful to detect areas of devitalization before surgery. Bone marrow edema on fluid-sensitive images and low signal intensity on T1-weighted images in the presence of secondary MRI findings, including ulcer, sinus tract, and cellulitis with or without abscess are typical findings of osteomyelitis. If MRI is contraindicated, three phase bone scan can be used. Early diagnosis and treatment is essential.

Asunto(s)

RESUMEN

MRI is a valuable tool for diagnosing a broad spectrum of acute and chronic ankle disorders, including ligament tears, tendinopathy, and osteochondral lesions. Traditional two-dimensional (2D) MRI provides a high image signal and contrast of anatomic structures for accurately characterizing articular cartilage, bone marrow, synovium, ligaments, tendons, and nerves. However, 2D MRI limitations are thick slices and fixed slice orientations. In clinical practice, 2D MRI is limited to 2 to 3 mm slice thickness, which can cause blurred contours of oblique structures due to volume averaging effects within the image slice. In addition, image plane orientations are fixated and cannot be changed after the scan, resulting in 2D MRI lacking multiplanar and multiaxial reformation abilities for individualized image plane orientations along oblique and curved anatomic structures, such as ankle ligaments and tendons. In contrast, three-dimensional (3D) MRI is a newer, clinically available MRI technique capable of acquiring high-resolution ankle MRI data sets with isotropic voxel size. The inherently high spatial resolution of 3D MRI permits up to five times thinner (0.5 mm) image slices. In addition, 3D MRI can be acquired image voxel with the same edge length in all three space dimensions (isotropism), permitting unrestricted multiplanar and multiaxial image reformation and postprocessing after the MRI scan. Clinical 3D MRI of the ankle with 0.5 to 0.7 mm isotropic voxel size resolves the smallest anatomic ankle structures and abnormalities of ligament and tendon fibers, osteochondral lesions, and nerves. After acquiring the images, operators can align image planes individually along any anatomic structure of interest, such as ligaments and tendons segments. In addition, curved multiplanar image reformations can unfold the entire course of multiaxially curved structures, such as perimalleolar tendons, into one image plane. We recommend adding 3D MRI pulse sequences to traditional 2D MRI protocols to visualize small and curved ankle structures to better advantage. This article provides an overview of the clinical application of 3D MRI of the ankle, compares diagnostic performances of 2D and 3D MRI for diagnosing ankle abnormalities, and illustrates clinical 3D ankle MRI applications.

Asunto(s)

RESUMEN

This article is meant to serve as a reference for radiologists, orthopedic surgeons, and other physicians to enhance their understanding of progressive collapsing foot deformity, also known as adult acquired flat foot deformity. Pathophysiology, imaging findings, especially on MRI and 3-dimensional MRI are discussed with relevant illustrations so that the readers can apply these principles in their practice for better patient managements.

Asunto(s)

RESUMEN

The increase in competitive sports practice among children and lack of ionizing radiation have resulted in a higher demand for MRI examinations. MRI of the children skeleton has some particularities that can lead orthopedists, pediatricians, and radiologists to diagnostic errors. The foot and ankle have several bones with abundant radiolucent and high signal intensity cartilage in several ossification centers, apophysis and physis, that can make this interpretation even harder. The present revision aims to show, how to differentiate between normal developmental findings and anatomic variants from pathologic conditions, whether mechanical, inflammatory, infectious, or neoplastic.

Asunto(s)

RESUMEN

Peripheral neuropathies of the foot and ankle can be challenging to diagnose clinically due to concomitant traumatic and nontraumatic or degenerative orthopedic conditions. Although clinical history, physical examination, and electrodiagnostic testing comprised of nerve conduction velocities and electromyography are used primarily for the identification and classification of peripheral nerve disorders, MR neurography (MRN) can be used to visualize the peripheral nerves as well as the skeletal muscles of the foot and ankle for primary neurogenic pathology and skeletal muscle denervation effect. Proper knowledge of the anatomy and pathophysiology of peripheral nerves is important for an MRN interpretation.

Asunto(s)

RESUMEN

Subarachnoid hemorrhage (SAH) is defined as sudden bleeding into the subarachnoid space. Although its incidence is low, mortality remains high. The most frequent cause of spontaneous SAH is aneurysm rupture. Cerebral CT scans are highly sensitive in ruling out SAH within the first 6 hours. Due to the recent improvement in imaging resolution, only a strong clinical suspicion can justify a cerebrospinal fluid analysis if the CT scan is normal after 6 hours. Cerebral MRI is also highly sensitive in both the acute and sub-acute phases. This article reviews the various clinical and paraclinical elements of the diagnostic approach, the main etiologies and the risk factors associated with SAH.

L'hémorragie sous-arachnoïdienne (HSA) se définit par un saignement brutal dans l'espace sous-arachnoïdien. Bien que son incidence soit faible, la mortalité demeure élevée. La cause la plus fréquente d'une HSA spontanée est une rupture d'anévrisme. Le CT-scan cérébral présente une sensibilité très élevée pour exclure une HSA dans les 6 premières heures. Grâce à l'amélioration récente du pouvoir de résolution de l'imagerie, seule une forte suspicion clinique peut motiver une analyse du liquide céphalorachidien si le CT-scan est normal au-delà de 6 heures. L'IRM cérébrale a également une sensibilité élevée à la fois aux phases aiguë et subaiguë. Cet article passe en revue les différents éléments cliniques et paracliniques de l'approche diagnostique, les principales étiologies ainsi que les facteurs de risques associés à l'HSA.

Asunto(s)

RESUMEN

BACKGROUND: Recent studies suggested that persons with migraine might be at higher risk of structural brain changes, including cerebral small vessel disease and atrophy. However, findings in the literature are inconsistent, with variations observed in the direction, magnitude, and population characteristics of reported effects, and large-scale population-based evidence remains scarce. Hence, we investigated the association of migraine with structural brain changes in a middle-aged and elderly population. METHODS: Within the population-based Rotterdam Study, lifetime history of migraine was assessed using a validated questionnaire between 2006 and 2011. Magnetic resonance imaging of the brain was performed in 4920 participants (median age 61.7 [IQR 45.5, 97.5] years, 55.4% female) to assess imaging markers of cerebral small vessel disease and brain atrophy. We used linear and logistic regression models to examine the cross-sectional association of migraine with brain volumes (total grey and white matter volumes in mL) and cerebral small vessel disease markers (white matter hyperintensity volume in mL, presence of lacunes and cerebral microbleeds). Adjustments were made for age, sex, intracranial volume and cardiovascular variables. Analyses were also stratified by sex and presence of aura. RESULTS: The lifetime prevalence of migraine was 15.3% (752/4920). In multivariable adjusted regression models, we found no statistically significant differences between participants with and without migraine in terms of total brain volume (mean difference [MD]: 2.21 mL, 95% confidence interval [CI]: -0.38 ; 4.81), grey matter volume (MD: 0.38 mL, 95% CI: -1.98 ; 2.74), white matter volume (MD: 2.19 mL, 95% CI: -0.56 ; 4.93), log white matter hyperintensity volume (MD: -0.04 mL, 95% CI: -0.10 ; 0.02), presence of lacunes (odds ratio [OR]: 0.82, 95% CI: 0.58-1.15), and presence of cerebral microbleeds (OR: 0.95, 95% CI: 0.76-1.18). CONCLUSION: In this study, we found that middle-aged and elderly participants with migraine were not more likely to have structural brain changes on magnetic resonance imaging.

Asunto(s)

Asunto(s)