30 research outputs found
THE INFLUENCE OF SONOGRAPHER EXPERIENCE ON MEASUREMENTS OF SKELETAL MUSCLE CROSS-SECTIONAL AREA
Jonathan P. Beausejour1, Caleb C. Voskuil2, Dustin Dunnick3, Kristen M. Badillo1, Joel E. Harden4, Jason I. Pagan1, Kylie K. Harmon1, Ryan M. Girts1, Gena R. Gerstner4, Joshua C. Carr2, Matt S. Stock1. 1University of Central Florida, Orlando, FL. 2Texas Christian University, Fort Worth, TX. 3Arkansas Tech University, Russellville, AR. 4Old Dominion University, Norfolk, VA.
BACKGROUND: The affordability and convenience of B-mode ultrasound devices has made their use widespread in university research settings, clinics, and hospitals. As such, establishing a reliable image acquisition protocol is essential for reporting consistent measurements. Since ultrasound image acquisition requires training and skill, relying on the same sonographer to conduct all imaging can be challenging, especially if turnover of research support is frequent. The purpose of this study was to investigate whether sonographer experience influences ultrasound-derived measures of muscle cross-sectional area (mCSA). By assessing three muscles, we sought to determine whether the influence of experience is muscle specific. METHODS: An experienced (7 years) and novice sonographer independently acquired images of the biceps brachii, vastus lateralis, and medial gastrocnemius of 17 participants (10 females, 7 males; mean ± SD age = 22 ± 3 years). Images were captured in the transverse plane with use of a panoramic function while participants rested in the supine (biceps brachii, vastus lateralis) or prone (medial gastrocnemius) position. Before data collection, the novice sonographer engaged in a 2-hr training session with the experienced sonographer, which included acquiring images together on 2 pilot participants not included in the sample. The sonographers were not together in the laboratory during image acquisition and the order in which images were acquired between sonographers and muscles was randomized. Images were analyzed in ImageJ by a blinded, experienced investigator not present during data collection. Statistical analyses included paired samples t-tests, Cohen’s d effect sizes, intraclass correlation coefficients (ICC ), and the standard error of measurement (SEM). RESULTS: Similar mCSA values were observed for the biceps brachii (p = .280, d = .271, ICC = .975, SEM = 6.5%) and vastus lateralis (p = .417, d = .202, ICC = .986, SEM = 6.6%). There were significant differences between sonographers for the medial gastrocnemius (p = .035; d = .559; ICC = .939, SEM = 8.2%). CONCLUSION: The influence of sonographer experience on mCSA measurements is muscle specific. Specifically, medial gastrocnemius mCSA values differ between an experienced versus a novice sonographer. Our findings have important implications for laboratories that use ultrasound and possess research team members of varying experience levels
Interobserver agreement in distinguishing large adrenal adenomas and adrenocortical carcinomas on computed tomography
Methodological considerations of electron spin resonance spin trapping techniques for measuring reactive oxygen species generated from metal oxide nanomaterials
The effect of zirconium doping of cerium dioxide nanoparticles on pulmonary and cardiovascular toxicity and biodistribution in mice after inhalation
Development and manufacture of nanomaterials is growing at an exponential rate, despite an incomplete understanding of how their physicochemical characteristics affect their potential toxicity. Redox activity has been suggested to be an important physicochemical property of nanomaterials to predict their biological activity. This study assessed the influence of redox activity by modification of cerium dioxide nanoparticles (CeO2 NPs) via zirconium (Zr) doping on the biodistribution, pulmonary and cardiovascular effects in mice following inhalation. Healthy mice (C57BL/6 J), mice prone to cardiovascular disease (ApoE−/−, western-diet fed) and a mouse model of neurological disease (5 × FAD) were exposed via nose-only inhalation to CeO2 NPs with varying amounts of Zr-doping (0%, 27% or 78% Zr), or clean air, over a four-week period (4 mg/m3 for 3 h/day, 5 days/week). Effects were assessed four weeks post-exposure. In all three mouse models CeO2 NP exposure had no major toxicological effects apart from some modest inflammatory histopathology in the lung, which was not related to the amount of Zr-doping. In ApoE−/− mice CeO2 did not change the size of atherosclerotic plaques, but there was a trend towards increased inflammatory cell content in relation to the Zr content of the CeO2 NPs. These findings show that subacute inhalation of CeO2 NPs causes minimal pulmonary and cardiovascular effect four weeks post-exposure and that Zr-doping of CeO2 NPs has limited effect on these responses. Further studies with nanomaterials with a higher inherent toxicity or a broader range of redox activities are needed to fully assess the influence of redox activity on the toxicity of nanomaterials