Changing trends in anabolic-androgenic steroid use within Scottish prisons: Detection, prevalence, and quantitation.

Anabolic-androgenic steroids (AASs) are a subclassification of image performance enhancing drugs (IPEDs). While AAS use is most prevalent among people in athletics, there is also high lifetime prevalence of AAS use among prisoners. This study reports the qualitative detection of AASs in seized samples from the Scottish prisons from 2019-2023. Additionally, methods were developed for the quantitative analysis of AASs using gas chromatography-mass spectrometry (GC-MS) and applied to 61 samples of tablets or powders seized from Scottish prisons between July 2022 and July 2023. Since 2022, there has been an increase in AAS detections in the Scottish prisons. Oxymetholone was the most prevalent AAS, followed by metandienone (methandrostenolone, methandienone), methyltestosterone, oxandrolone, mestanolone (methylandrostanolone), stanozolol, and androstenedione. Multiple AASs were found in 21 samples and 10 samples contained other drugs, including amitriptyline, sertraline, zopiclone, mirtazapine, sildenafil, etizolam, Δ9-tetrahydrocannabinol, and the synthetic cannabinoid MDMB-INACA. Most AAS samples were tablets (77.0%), although they were also detected in powders, herbal material, e-cigarettes, and a fragmented soap bar-type sample. There was a large variation in the concentration of AASs in the tablets and powders seized from the Scottish prisons, demonstrating AASs are another highly variable component of the polydrug use situation in prisons, the effects of which need to be examined further.

Utility of block-matching and 3D filter for reproducibility of lung density and denoising in low-dose chest CT: A pilot study.

PURPOSE: This study aimed to acquire an image quality consistent with that of full-dose chest computed tomography (CT) when obtaining low-dose chest CT images and to analyze the effects of block-matching and 3D (BM3D) filters on lung density measurements and noise reduction in lung parenchyma. METHODS: Using full-dose chest CT images, we evaluated lung density measurements and noise reduction in lung parenchyma images for low-dose chest CT. Three filters (median, Wiener, and the proposed BM3D) were applied to low-dose chest CT images for comparison and analysis with images from full-dose chest CT. To evaluate lung density measurements, we measured CT attenuation at the 15th percentile of the lung CT histogram. The coefficient of variation (COV) and contrast-to-noise ratio (CNR) were used to evaluate the noise level. RESULTS: The 15th percentile of the lung CT histogram showed the smallest difference between full- and low-dose CT when applying the BM3D filter, and the highest difference between full- and low-dose CT without filters (full-dose =  - 926.28 ± 0.32, BM3D =  - 926.65 ± 0.32, and low-dose =  - 959.43 ± 0.95) (p < 0.05). The COV was smallest when applying the BM3D filter, whereas the CNR was the highest (p < 0.05). CONCLUSIONS: The results of the study prove that the BM3D filter can reduce image noise while increasing the reproducibility of the lung density, even for low-dose chest CT.

Imaging performance of thoracic SMARCA4-deficient undifferentiated tumor: a case report and literature review.

Background: SMARCA4-deficient undifferentiated tumor (SMARCA4-UT) is a class of high-grade malignant tumors that has only been described in recent years, with an undifferentiated or rhabdoid morphology and genetic deletion of SMARCA4 (BRG1), a subunit of the BRG1-associated factors (BAFs) chromatin remodeling complex. It is a rare tumor type that occurs in young to middle-aged men and usually presents as a compressive thoracic mass with rapid progression and poor prognosis. However, much remains unknown about the clinical and imaging manifestations of the disease. Case Description: Herein, we report a 51-year-old man who came to our hospital with multiple enlarged lymph nodes in the chest after a computed tomography (CT) examination at another hospital. The patient underwent conventional ultrasound (US), contrast-enhanced ultrasound (CEUS), magnetic resonance imaging (MRI), 18F-fluorodeoxyglucose positron emission tomography/CT (PET/CT), and finally confirmed the diagnosis of SMARCA4-UT by US-guided puncture biopsy. After symptomatic management, the patient was transferred to another hospital and we performed a short-term follow-up. Conclusions: During this procedure, we obtained a series of relevant clinical and imaging data, especially US and CEUS images, which were described for the first time, offering valuable imaging information that will contribute to the clinical diagnosis of this disease to a certain extent. Moreover, this case highlights the efficacy of CEUS in identifying internal necrosis within tumors and lymph nodes, thereby improving the success rate of obtaining tumor tissue for pathological diagnosis. These findings substantiate the practical utility of US and CEUS in the context of mediastinal SMARCA4-UT, emphasizing their potential for widespread clinical adoption.

[Combination of lens decentration and tilt in phakic and pseudophakic eyes-Optical simulation of defocus, astigmatism and coma]. / Kombination aus Dezentrierung und Verkippung der Linse im phaken und pseudophaken Auge ­ optische Simulation von Defokus, Astigmatismus und Coma.

BACKGROUND AND PURPOSE: The effect of lens decentration and tilt on retinal image quality has been extensively studied in the past in simulations and clinical studies. The purpose of this study was to analyze the effect of combined lens decentration and tilt on the induction of defocus, astigmatism and coma in phakic and pseudophakic eyes. METHODS: Simulations were performed with Zemax on the Liou-Brennan schematic model eye. Based on the position of the gradient lens the image plane was determined (best focus). The lens was decentered horizontally from -1.0 mm to 1.0 mm in steps of 0.2 mm and tilted with respect to the vertical axis from -10° to 10° in steps of 2° (in total 121 combinations of decentration and tilt). For each combination of decentration and tilt defocus, astigmatism (in 0/180°) and horizontal coma was extracted from wave front error and recorded for a pupil size of 4 mm. After replacement of the gradient lens with an aberration correcting artificial lens implant model with the equatorial plane of the artificial lens aligned to the equatorial plane of the gradient lens, the simulations were repeated for the pseudophakic eye model. RESULTS: For the lens positioned according to the Liou-Brennan schematic model eye the simulation yielded a defocus of 0.026 dpt/-0.001 dpt, astigmatism of -0.045 dpt/-0.018 dpt, and a coma of -0.015 µm/0.047 µm for phakic/pseudophakic eyes. Maximum values were observed for a horizontal decentration of 1.0 mm and a tilt with respect to the vertical axis of 10° with 1.547 dpt/2.982 dpt for defocus, 0.971 dpt/1.871 dpt for astigmatism, and 0.441 µm/1.209 µm for coma. Maximum negative values occurred in phakic/pseudophakic eyes with -0.293 dpt/-1.224 dpt for defocus, for astigmatism -0.625 dpt/-0.663 dpt and for coma -0.491 µm /-0.559 µm, respectively. CONCLUSION: In this simulation study the effect of a combination of lens decentration in horizontal direction and tilt with respect to the vertical axis on defocus, astigmatism and horizontal coma was analyzed. The results may help to describe in clinical routine if with a decentered or tilted artificial lens implant the postoperative refraction does not match the target refraction or the resulting astigmatism after cataract surgery is not fully explained by measurement of corneal astigmatism.

Effectiveness of Non-Local Means Algorithm with an Industrial 3 MeV LINAC High-Energy X-Ray System for Non-Destructive Testing.

Industrial high-energy X-ray imaging systems are widely used for non-destructive testing (NDT) to detect defects in the internal structure of objects. Research on X-ray image noise reduction techniques using image processing has been widely conducted with the aim of improving the detection of defects in objects. In this paper, we propose a non-local means (NLM) denoising algorithm to improve the quality of images obtained using an industrial 3 MeV high-energy X-ray imaging system. We acquired X-ray images using various castings and assessed the performance visually and by obtaining the intensity profile, contrast-to-noise ratio, coefficient of variation, and normalized noise power spectrum. Overall, the quality of images processed by the proposed NLM algorithm is superior to those processed by existing algorithms for the acquired casting images. In conclusion, the NLM denoising algorithm offers an efficient and competitive approach to overcome the noise problem in high-energy X-ray imaging systems, and we expect the accompanying image processing software to facilitate and improve image restoration.

Theoretical image performance with customized aspheric and spherical IOLs - when do we get a benefit from customized aspheric design?

BACKGROUND & PURPOSE: Implantation of an artificial intraocular lens (IOL) during cataract surgery significantly changes the balance of aberrations in the eye. We demonstrate the theoretical superiority of customized aspheric IOL designs over standard spherical IOLs for different values of corneal curvature, asphericity and axial length. METHODS: For a selected set of corneal surfaces we calculated a best-fit equiconvex spherical IOL. In a second step we customized the IOL back surface to correct the wavefront aberrations of the cornea. Then we calculated a quadric approximation of the IOL back surface to retrieve the aspheric parameters of the customized lens in terms of radius of curvature and asphericity/conic constant. The optical performance of the three IOL models was monitored in terms of lateral ray spread (LRS) at retinal plane for variations of corneal curvatures, asphericity and axial lengths of the pseudophakic eye. RESULTS: The LRS of customized aspheric IOLs was significantly smaller compared to that of spherical IOLs (typically between 10 and 25 dB). For high aspheric coefficients the LRS increased with spherical IOLs. With aspheric IOLs LRS was higher for steep corneas paired with high aspheric coefficients, mostly due to the fitting error of the quadratic function. For several combinations of corneal curvature and aspheric coefficients the focal point of the aspheric IOL was up to 400 times smaller than the spherical one. CONCLUSION: This study appeals to the reader for the potential benefit of customized aspheric IOL design instead of the principle of a 'one size fits all' aspheric coefficient as used currently in clinical practice. A benefit with customized IOLs is less depending from the axial length and can be achieved with corneas of a moderate prolate aspheric shape with an equal or more negative Q value than the average of -0.22. Longer eyes seem to benefit less than short eyes.