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The use of electromagnetism and the design of antennas in the field of medical imaging have played important roles in clinical practice. Specifically, magnetic resonance imaging (MRI) utilizes transmission and reception antennas, or coils, that are tuned to specific frequencies depending on the strength of the main magnet. Clinical scanners operating at 3 Teslas (T) function at a frequency of 127 MHz, while research scanners at 7 T operate at 300 MHz. An 11.74 T scanner for human imaging, which is currently under development, will operate at a frequency of 500 MHz. MRI allows for the high‐definition scanning of biological tissues, making it a valuable tool for enhancing images acquired with positron emission tomography (PET). PET is an imaging modality used to evaluate the metabolism of organs or cancers. With recent advancements in the development of portable PET systems that can be integrated into any MRI scanner, we propose the design based on electromagnetic simulations of a triple‐tuned array of dipole antennas to operate at 127, 300, and 500 MHz. This array can be attached to the PET inset and used in 3, 7, or 11.74 T scanners. [ABSTRACT FROM AUTHOR]

Background: Previous epidemiological studies have suggested that phthalate exposure may contribute to neurocognitive and neurobehavioral disorders and decreased muscle strength and bone mass, all of which may be associated with reduced physical performance. Walking speed is a reliable assessment tool for measuring physical performance in adults age 60 y and older. Objective: We investigated associations between urinary phthalate metabolites and slowness of walking speed in community-dwelling adults ages 60-98 y. Methods: We analyzed 1,190 older adults [range, 60-98 y of age; mean [+ or -] standard deviation (SD), 74.81 [+ or -] 5.99] from the Korean Elderly Environmental Panel II study and measured repeatedly up to three times between 2012 and 2014. Phthalate exposure was estimated using the following phthalate metabolites in urine samples: mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-n-butyl phthalate (MnBP), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), and mono-benzyl phthalate (MBzP). Slowness was defined as a walking speed of Results: At enrollment, MBzP levels were associated with an increased odds of slowness [odds ratio (OR) per doubling increase: 1.15, 95% confidence interval (CI): 1.02, 1.30; OR for the highest vs. lowest quartile: 2.20 (95% CI: 1.12, 4.35) with p-trend across quartiles = 0.031]. In longitudinal analyses, MEHHP levels showed an increased risk of slowness [OR per doubling increase: 1.15 (95% CI: 1.02, 1.29), OR for the highest vs. lowest quartile: 1.47 (95% CI: 1.04, 2.06), p- trend = 0.035]; whereas those with higher MnBP showed a reduced risk of slowness [OR per doubling increase: 0.84 (95% CI: 0.74, 0.96), OR in the highest (vs. lowest) quartile: 0.64 (95% CI: 0.47, 0.87), p-trend = 0.006]. For linear regression models, MBzP quartiles were associated with slower walking speed (p-trend = 0.048) at enrollment, whereas MEHHP quartiles were associated with slower walking speed, and MnBP quartiles were associated with faster walking speed in longitudinal analysis (p-trend = 0.026 and Discussion: Urinary concentrations of prevalent phthalates exhibited significant associations with slow walking speed in adults ages 60-98 y. https://doi.org/10.1289/EHP10549, Introduction Walking speed is one of the quickest, most reliable, and simple measurements for monitoring the mobility and physical function of older adults. (1) Along with blood pressure, pulse rate, [...]

Magnetic resonance imaging (MRI) for preclinical analysis is useful for testing medical procedures, therapies, and drug development. Preclinical MRI uses small animals, such as mice, for multiple studies. Preclinical studies are often needed to control target mouse models with different parameters; thus, performing simultaneous MRIs is desired to reduce study time and provide a fair comparison. In this study, we propose a variation of a birdcage coil that is capable of providing the same field intensity for each mouse compared to a traditional birdcage coil configuration. The arrangement of the proposed birdcage coil produces a uniform and strongly localized magnetic |B1|-field in each of the four target mice. The design involves rotating the legs of the birdcage coil so that the current distribution produces a uniform field inside each mouse. Electromagnetic simulations were performed to validate the proposed design. The proposed design exhibited a better field intensity than the reference linear, circularly polarized mode birdcage coils and an eight-channel loop array coil. The proposed customized birdcage coil arrangement promises a better field intensity and uniformity across multiple mouse imaging using 9.4 T preclinical MRI scanners. [ABSTRACT FROM AUTHOR]

Background: It has often been reported that thyroid-specific autoimmune diseases (ADs), such as Hashimoto's thyroiditis and Graves' disease, could increase the risk of thyroid cancer, but the association between other ADs beyond thyroid and thyroid cancer has not been well investigated. This study aimed to examine the risk of thyroid cancer in patients with eight ADs compared with those without ADs. Methods: This nationwide retrospective matched cohort study was conducted to investigate the relationship of eight ADs (Hashimoto's thyroiditis, Graves' disease, type 1 diabetes mellitus, Sjogren's disease, inflammatory bowel disease [IBD], vitiligo, systemic lupus erythematosus, and rheumatoid arthritis [RA]) with the risk of incident thyroid cancer using the National Health Insurance Service-National Sample Cohort. The Cox-proportional hazard model was used to estimate the adjusted hazard ratio (HR) and confidence intervals (CI) for thyroid cancer in relation to each of AD compared with control group without AD. Results: During the average follow-up of 9.49 years, 138 thyroid cancer cases were newly developed in control group and 268 cases were occurred in group with 8 ADs. For all of study participants, the risk of thyroid cancer was significantly increased in patients with Hashimoto's thyroiditis (HR = 2.10 [1.57–2.81]), Graves' disease (HR = 2.67 [1.99–3.62]), IBD (HR = 2.06 [1.50–2.83]), vitiligo (HR = 1.71 [1.13–2.59]), RA (HR = 1.76 [1.07–2.90]), and total of 8 ADs (HR = 1.97 [1.60–2.42]) compared with control group without ADs. When ADs were divided into three types, thyroid-specific ADs (HR = 2.37 [1.85–3.03]) showed the strongest and significant association with thyroid cancer, followed by local ADs (HR = 1.83 [1.41–2.38]), and systemic ADs (HR = 1.77 [1.14–2.74]). Conclusions: Specific ADs—especially for thyroid-specific AD, vitiligo, IBD, and RA—were associated with increased risk for thyroid cancer. [ABSTRACT FROM AUTHOR]