Σφακιανάκης Αλέξανδρος
ΩτοΡινοΛαρυγγολόγος
Αναπαύσεως 5 Άγιος Νικόλαος
Κρήτη 72100
00302841026182
00306932607174
alsfakia@gmail.com

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Κυριακή 18 Δεκεμβρίου 2022

Brachial Plexus Magnetic Resonance Neurography: Technical Challenges and Solutions

alexandrossfakianakis shared this article with you from Inoreader
imageMagnetic resonance neurography of the brachial plexus (BP) is challenging owing to its complex anatomy and technical obstacles around this anatomic region. Magnetic resonance techniques to improve image quality center around increasing nerve-to-background contrast ratio and mitigating imaging artifacts. General considerations include unilateral imaging of the BP at 3.0 T, appropriate selection and placement of surface coils, and optimization of pulse sequences. Technical considerations to improve nerve conspicuity include fat, vascular, and respiratory artifact suppression techniques; metal ar tifact reduction techniques; and 3-dimensional sequences. Specific optimization of these techniques for BP magnetic resonance neurography greatly improves image quality and diagnostic confidence to help guide nonoperative and operative management.
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Modern Low-Field MRI of the Musculoskeletal System: Practice Considerations, Opportunities, and Challenges

alexandrossfakianakis shared this article with you from Inoreader
imageMagnetic resonance imaging (MRI) provides essential information for diagnosing and treating musculoskeletal disorders. Although most musculoskeletal MRI examinations are performed at 1.5 and 3.0 T, modern low-field MRI systems offer new opportunities for affordable MRI worldwide. In 2021, a 0.55 T modern low-field, whole-body MRI system with an 80-cm-wide bore was introduced for clinical use in the United States and Europe. Compared with current higher-field-strength MRI systems, the 0.55 T MRI system has a lower total ownership cost, including purchase price, installation, and maintenance. Althou gh signal-to-noise ratios scale with field strength, modern signal transmission and receiver chains improve signal yield compared with older low-field magnetic resonance scanner generations. Advanced radiofrequency coils permit short echo spacing and overall compacter echo trains than previously possible. Deep learning–based advanced image reconstruction algorithms provide substantial improvements in perceived signal-to-noise ratios, contrast, and spatial resolution. Musculoskeletal tissue contrast evolutions behave differently at 0.55 T, which requires careful consideration when designing pulse sequences. Similar to other field strengths, parallel imaging and simultaneous multislice acquisition techniques are vital for efficient musculoskeletal MRI acquisitions. Pliable receiver coils with a more cost-effective design offer a path to more affordable surface coils and improve image quality. Whereas fat suppression is inherently more challenging at lower field strengths, chemical s hift selective fat suppression is reliable and homogeneous with modern low-field MRI technology. Dixon-based gradient echo pulse sequences provide efficient and reliable multicontrast options, including postcontrast MRI. Metal artifact reduction MRI benefits substantially from the lower field strength, including slice encoding for metal artifact correction for effective metal artifact reduction of high-susceptibility metallic implants. Wide-bore scanner designs offer exciting opportunities for interventional MRI. This review provides an overview of the economical aspects, signal and image quality considerations, technological components and coils, musculoskeletal tissue relaxation times, and image contrast of modern low-field MRI and discusses the mainstream and new applications, challenges, and opportunities of musculoskeletal MRI.
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Changes in endemic patterns of respiratory syncytial virus infection in pediatric patients under the pressure of nonpharmaceutical interventions for COVID‐19 in Beijing, China

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Background

A series of nonpharmaceutical interventions (NPIs) was launched in Beijing, China, on January 24, 2020, to control coronavirus disease 2019.

Methods

To reveal the roles of NPIs on respiratory syncytial virus (RSV), respiratory specimens collected from children with acute respiratory tract infection during Jul 2017 and Dec 2021 in Beijing were screened by CEMP assay. Specimens positive for RSV were subjected to PCR and genotyped by G gene sequencing and phylogenetic analysis using iqtree v1.6.12. The paraFix mutations were analyzed with the R package sitePath. Clinical data were compared using SPSS 22.0 software.

Results

Before NPIs launched, each RSV endemic season started from Oct/Nov to Feb/Mar of the next year in Beijing. After that, the RSV positive rate abruptly dropped from 31.93% in Jan to 4.39% in Feb 2020; then, a dormant state with RSV positive rates ≤1% from Mar to Sep, a nearly dormant state in Oct (2.85%) and Nov (2.98%) and a delayed endemic season in 2020, and abnormal RSV positive rates remaining at approximately 10% in summer until Sep 2021 were detected. Finally, an endemic RSV season returned from Oct 2021. There was a game between subtypes A and B, and RSV-A replaced RSV-B in July 2021 to become the dominant subtype. Six RSV-A and 8 RSV-B paraFix (parallel and fixed) mutations were identified on G. The percentage of severe pneumonia patients decreased to 40.51% after NPIs launched.

Conclusions

NPIs launched in Beijing seriously interfered with the endemic season of RSV.

This article is protected by copyright. All rights reserved.

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Prevalence of post-COVID Condition 12 Weeks after Omicron Infection Compared to Negative Controls and Association with Vaccination Status

alexandrossfakianakis shared this article with you from Inoreader

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ABSTRACT
Background
Post-COVID symptoms can persist several months after SARS-CoV-2 infection. Little is known, however, about the prevalence of post-COVID condition following infections from Omicron variants and how this varies according to vaccination status
Objective
This study evaluates the prevalence of symptoms and functional impairment 12 weeks after an infection by Omicron variants (BA.1 and BA.2) compared to negative controls tested during the same peri od.
Methods
Outpatient individuals tested positive or negative for COVID-19 infection between December 2021 and February 2022 at the Geneva University Hospitals were followed 12 weeks after their test date.
Results
Overall, 11.7% of Omicron cases had symptoms 12 weeks after the infection compared to 10.4% of individuals who tested negative during the same period (p < 0.001), and symptoms were much less common in vaccinated vs non-vaccinated individuals with Omicron infection (9.7% vs 18.1%, p < 0.001). There were no significant differences in functional impairment at 12 weeks between Omicron cases and negative controls even after adjusting for multiple potential confounders.
Conclusion
The differential prevalence of post-COVID symptoms and functional impairment attributed to Omicron BA.1 and BA.2 infection is low when compared to negative controls. Vaccination is associated with lower prevalence of post-COVID symptoms.
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Errors of Interpretation - correcting the record on the comparative efficacy of surgical masks versus respirators

alexandrossfakianakis shared this article with you from Inoreader

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Tuberculosis and the Risk of Ischemic Heart Disease: A Nationwide Cohort Study

alexandrossfakianakis shared this article with you from Inoreader

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Abstract
Background
Little is known about the risk of ischemic heart disease (IHD) in tuberculosis (TB) survivors.
Methods
We performed a population-based retrospective cohort study using the Korean National Health Insurance Service database. TB survivors (n = 60,602) and their 1:1 age- and sex-matched controls (n = 60,602) were enrolled. Eligible participants were followed up from 1 year after their TB diagnosis to the date of an IHD event, date of deat h, or the end of the study period (December 31, 2018), whichever came first. The risk of IHD was estimated using a Cox proportional hazards regression, and stratified analyses were performed for related factors. Among IHD events, we additionally analyzed for myocardial infarction (MI).
Results
During a median of 3.9 years of follow-up, 2.7% of TB survivors (1,633/60,602) and 2.0% of the matched controls (1,228/60,602) developed IHD, and 0.6% of TB patients (341/60,602) and 0.4% of the matched controls (223/60,602) developed MI. The overall risk of developing IHD and MI was higher in TB patients (adjusted hazard [aHR] 1.21, 95% CI 1.12–1.32 for IHD and aHR 1.48, 95% CI 1.23–1.78 for MI) than in the matched controls. Stratified analyses showed that TB survivors have an increased risk of IHD and MI regardless of income, place of residence, smoking status, alcohol consumption, physical activity, body mass index, and Charlson comorbidity index.
Conclusions
TB surviv ors have a higher risk of IHD than matched controls. Strategies are needed to reduce the burden of IHD in TB survivors.
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Πέμπτη 15 Δεκεμβρίου 2022

Recommendation for imaging follow‐up strategy based on time‐specific disease failure for nasopharyngeal carcinoma

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Background

To develop a common follow-up strategy for appropriate imaging examination at an appropriate time for nasopharyngeal carcinoma (NPC).

Methods

Independent prognostic factors were identified by Cox regression analysis, and a nomogram model was developed. Random survival forest (RSF) model was constructed to depict probability of disease failure during a 5-year follow-up and establish a reasonable risk-based follow-up strategy.

Results

The nomogram model finally categorized the patients into three risk groups. RSF model demonstrated distribution trends for local and regional recurrences, bone metastasis, liver metastasis, and lung metastasis of NPC. Adequate imaging at follow-up should be considered between 10 and 21 months for patients at moderate-risk of recurrence or metastasis and 7–36 months for those at high-risk.

Conclusions

The temporal distribution of incidence rates of recurrence or metastasis varied among different risk groups. We recommend implementing a focused and targeted imaging surveillance intervention at appropriate times to improve its efficiency and reduce costs.

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