Quantitative MRI for Evaluation of Musculoskeletal Disease: Cartilage and Muscle Composition, Joint Inflammation, and Biomechanics in Osteoarthritis

alexandrossfakianakis shared this article with you from Inoreader Quantitative MRI for Evaluation of Musculoskeletal Disease: Cartilage and Muscle Composition, Joint Inflammation, and Biomechanics in Osteoarthritis via Investigative Radiology - Current Issue Magnetic resonance imaging (MRI) is a valuable tool for evaluating musculoskeletal disease as it offers a range of image contrasts that are sensitive to underlying tissue biochemical composition and microstructure. Although MRI has the ability to provide high-resolution, information-rich images suitable for musculoskeletal applications, most MRI utilization remains in qualitative evaluation. Quantitative MRI (qMRI) provides additional value beyond qualitative assessment via objective metrics that can support disease characterization, disease progression monitoring, or therapy response. In t his review, musculoskeletal qMRI techniques are summarized with a focus on techniques developed for osteoarthritis evaluation. Cartilage compositional MRI methods are described with a detailed discussion on relaxometric mapping (T2, T2*, T1ρ) without contrast agents. Methods to assess inflammation are described, including perfusion imaging, volume and signal changes, contrast-enhanced T1 mapping, and semiquantitative scoring systems. Quantitative characterization of structure and function by bone shape modeling and joint kinematics are described. Muscle evaluation by qMRI is discussed, including size (area, volume), relaxometric mapping (T1, T2, T1ρ), fat fraction quantification, diffusion imaging, and metabolic assessment by 31P-MR and creatine chemical exchange saturation transfer. Other notable technologies to support qMRI in musculoskeletal evaluation are described, including magnetic resonance fingerprinting, ultrashort echo time imaging, ultrahigh-field MRI, and hybrid MRI-p ositron emission tomography. Challenges for adopting and using qMRI in musculoskeletal evaluation are discussed, including the need for metal artifact suppression and qMRI standardization. View on Web

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Brachial Plexus Magnetic Resonance Neurography: Technical Challenges and Solutions

alexandrossfakianakis shared this article with you from Inoreader Brachial Plexus Magnetic Resonance Neurography: Technical Challenges and Solutions via Investigative Radiology - Current Issue Magnetic 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. View on Web

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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 Modern Low-Field MRI of the Musculoskeletal System: Practice Considerations, Opportunities, and Challenges via Investigative Radiology - Current Issue Magnetic 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. View on Web

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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 Changes in endemic patterns of respiratory syncytial virus infection in pediatric patients under the pressure of nonpharmaceutical interventions for COVID‐19 in Beijing, China via Journal of Medical Virology 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. View on Web

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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 Prevalence of post-COVID Condition 12 Weeks after Omicron Infection Compared to Negative Controls and Association with Vaccination Status via Clinical Infectious Diseases Advance Access 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. View on Web

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Weight and metabolic changes after switching from tenofovir alafenamide (TAF)/emtricitabine (FTC)+dolutegravir (DTG), tenofovir disoproxil fumarate (TDF)/FTC+DTG and TDF/FTC/efavirenz (EFV) to TDF/lamivudine (3TC)/DTG

alexandrossfakianakis shared this article with you from Inoreader Weight and metabolic changes after switching from tenofovir alafenamide (TAF)/emtricitabine (FTC)+dolutegravir (DTG), tenofovir disoproxil fumarate (TDF)/FTC+DTG and TDF/FTC/efavirenz (EFV) to TDF/lamivudine (3TC)/DTG via Clinical Infectious Diseases Advance Access Abstract Participants randomised to first-line tenofovir alafenamide (TAF)/emtricitabine (FTC)+dolutegravir (DTG), tenofovir disoproxil fumarate (TDF)/FTC+DTG or TDF/FTC/efavirenz (EFV) for 192 weeks were then switched to TDF/lamivudine (3TC)/DTG for 52 weeks. Participants switching either TAF/FTC+DTG or TDF/FTC/EFV to TDF/3TC/DTG showed statistically significant reductions in weight, low density lipoprotein, triglycerides, glucose and glycated haemoglobin. View on Web

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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 Errors of Interpretation - correcting the record on the comparative efficacy of surgical masks versus respirators via Clinical Infectious Diseases Advance Access View on Web

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