Characterization of breast calcification types using dual energy X-ray method

Calcifications are products of mineralization whose presence is usually associated with pathological conditions. The minerals mostly seen in several diseases are calcium oxalate (CaC2O4), calcium carbonate (CaCO3) and hydroxyapatite (HAp). Up to date, there is no in-vivo method that could discriminate between minerals. To this aim, a dual energy X-ray method was developed in the present study. An analytical model was implemented for the determination of the Calcium/Phosphorus mass ratio (mca/mp ). The simulation was carried out using monoenergetic and polyenergetic X-rays and various calcification thicknesses (100 to 1000 um) and types (CaC2O4, CaCO3, HAp). The experimental evaluation of the method was performed using the optimized irradiation conditions obtained from the simulation study. X-ray tubes, combined with energy dispersive and energy integrating (imaging) detectors, were used for the determination of the mca/mp in phantoms of different mineral types and thicknesses. Based on the results of the experimental procedure, statistical significant difference was observed between the different types of minerals when calcification thicknesses were 300 um or higher

Dual Energy Method for Breast Imaging: A Simulation Study

Dual energy methods can suppress the contrast between adipose and glandular tissues in the breast and therefore enhance the visibility of calcifications. In this study, a dual energy method based on analytical modeling was developed for the detection of minimum microcalcification thickness. To this aim, a modified radiographic X-ray unit was considered, in order to overcome the limited kVp range of mammographic units used in previous DE studies, combined with a high resolution CMOS sensor (pixel size of 22.5 m) for improved resolution. Various filter materials were examined based on their K-absorption edge. Hydroxyapatite (HAp) was used to simulate microcalcifications. The contrast to noise ratio (CNR ) of the subtracted images was calculated for both monoenergetic and polyenergetic X-ray beams. The optimum monoenergetic pair was 23/58 keV for the low and high energy, respectively, resulting in a minimum detectable microcalcification thickness of 100 m. In the polyenergetic X-ray study, the optimal spectral combination was 40/70 kVp filtered with 100 m cadmium and 1000 m copper, respectively. In this case, the minimum detectable microcalcification thickness was 150 m. The proposed dual energy method provides improved microcalcification detectability in breast imaging with mean glandular dose values within acceptable levels

Dual energy subtraction method for breast calcification imaging

The aim of this work was to present an experimental dual energy (DE) method for the visualization of microcalcifications (μCsμCs). A modified radiographic X-ray tube combined with a high resolution complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) X-ray detector was used. A 40/70 kV spectral combination was filtered with 100 μmμm cadmium (Cd) and 1000 μmμm copper (Cu) for the low/high-energy combination. Homogenous and inhomogeneous breast phantoms and two calcification phantoms were constructed with various calcification thicknesses, ranging from 16 to 152 μmμm. Contrast-to-noise ratio (CNR) was calculated from the DE subtracted images for various entrance surface doses. A calcification thickness of 152 μmμm was visible, with mean glandular doses (MGD) in the acceptable levels (below 3 mGy). Additional post-processing on the DE images of the inhomogeneous breast phantom resulted in a minimum visible calcification thickness of 93 μmμm (MGD=1.62 mGy). The proposed DE method could potentially improve calcification visibility in DE breast calcification imaging

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Clinical characteristics of COVID-19 in neonates and young infants

We report the clinical characteristics and management of fourteen neonates and very young infants with COVID-19. Although all presented with mild symptoms and did not require specific treatment, most of them had abnormal laboratory and radiological findings. Ten infants presented with neutropenia and/or monocytosis but none with lymphopenia. Transient hypertriglyceridemia and/or prolonged viral shedding were detected in 9 patients. Conclusion: Based to our experience, COVID-19 is mild in very young infants and might have distinct laboratory findings.What is Known:• SARS-CoV-2 in infants is a mild disease.• The period of transmission is approximately 2 weeks.What is New:• Very young age is not a risk factor for severe COVID-19 but could be associated with prolonged viral shedding.• Neutropenia and monocytosis are distinct characteristics of COVID-19 in very young infants. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature

Association of total and neutralizing SARS-CoV-2 spike -receptor binding domain antibodies with epidemiological and clinical characteristics after immunization with the 1st and 2nd doses of the BNT162b2 vaccine

Background: Data regarding the association of antibody levels elicited after immunization with the BNT162b2 mRNA COVID-19 vaccine with epidemiological and clinical parameters are limited. Methods: We prospectively measured the total (TAbs-RBD) and the neutralizing antibodies (NAbs-RBD) against the receptor binding domain (RBD) of SARS-CoV-2 spike protein in a cohort of 268 Healthcare workers before immunization, 20 days after the 1st dose and 30 days after the 2nd dose of the BNT162b2 vaccine. A statistical analysis for possible association of antibodies’ levels with epidemiological and clinical parameters was performed. Results: The mean age (±SD) of the participants was 45.45 years (±11.93) (range: 24–70 years) and 211 (79.9%) were females. Statistically significant differences were detected regarding both TAbs-RBD and NAbs-RBD between the first and second doses of the vaccine (P < 0.001). The median (IQR) percentage (%) of NAbs-RBD after the 1st dose was 51.07% (31.60%) and after the 2nd dose 95.31% (3.70%) (P < 0.001). The correlation between the TAbs-RBD and NAbs-RBD was after the 1st dose, Spearman's, rho: 0.861 (P < 0.001) and after the 2nd dose rho: 0.989 (P < 0.001). Twenty days after the 1st dose, 56/264 (21.2%) of the participants had low levels of NAbs-RBD, while one month after the 2nd dose all of them had protective levels of NAbs-RBD. After the 2nd vaccine dose, a statistically significant negative association of TAbs-RBD was detected for age (P < 0.001), smoking (P = 0.011), and immunosuppressive medications (P < 0.001), while a positive association was detected for BMI (P = 0.004) and systemic adverse events after immunization (P = 0.001). Conclusion: A significant correlation of TAbs-RBD and NAbs-RBD was detected after both vaccine doses. Older age, smoking, and immunosuppressive medications negatively affected the final antibody level after SARS-CoV-2 immunization. Our findings emphasize the significance of the 2nd vaccine dose especially in the older age groups. © 2021 Elsevier Lt

Pencil Beam Spectral Measurements of Ce, Ho, Yb, and Ba Powders for Potential Use in Medical Applications

The aim of the present study was to obtain modified X-ray spectra, by using appropriate filter materials for use in applications such as dual energy X-ray imaging. K-edge filtering technique was implemented in order to obtain narrow energy bands for both dual- and single-kVp techniques. Three lanthanide filters (cerium, holmium, and ytterbium) and a filter outside lanthanides (barium), with low K-edge, were used to modify the X-ray spectra. The X-ray energies that were used in this work ranged from 60 to 100 kVp. Relative root mean square error (RMSE) and the coefficient of variation were used for filter selection. The increasing filter thicknesses led to narrower energy bands. For the dual-kVp technique, 0.7916 g/cm2 Ho, 0.9422 g/cm2 Yb, and 1.0095 g/cm2 Yb were selected for 70, 80, and 90 kVp, respectively. For the single-kVp technique 0.5991 g/cm2 Ce, 0.8750 g/cm2 Ba, and 0.8654 g/cm2 Ce were selected for 80, 90, and 100 kVp, respectively. The filtered X-ray spectra of this work, after appropriate modification, could be used in various X-ray applications, such as dual-energy mammography, bone absorptiometry, and digital tomosynthesis

Application of a dual energy X-ray imaging method on breast specimen

The purpose of this study was to evaluate a dual energy method, developed by our group, on a breast cancer specimen. A modified radiographic X-ray tube combined with a high resolution complementary metal-oxide semiconductor (CMOS) active pixel sensor (APS) X-ray detector was used. A 40/70 kV spectral combination was filtered with 100 μm cadmium (Cd) and 1000 μm copper (Cu) for the low/high-energy combination. Dual energy images were obtained from a formalin-fixed breast cancer specimen for various entrance surface doses (ESD). Initial results showed that the DE images were directly comparable with the mammographic image and similar or even increased calcification information was identified, with mean glandular dose values at acceptable levels. Keywords: Dual energy, Calcifications, X-rays, CMO

Dual Energy Method for Breast Imaging: A Simulation Study

Dual energy methods can suppress the contrast between adipose and glandular tissues in the breast and therefore enhance the visibility of calcifications. In this study, a dual energy method based on analytical modeling was developed for the detection of minimum microcalcification thickness. To this aim, a modified radiographic X-ray unit was considered, in order to overcome the limited kVp range of mammographic units used in previous DE studies, combined with a high resolution CMOS sensor (pixel size of 22.5 μm) for improved resolution. Various filter materials were examined based on their K-absorption edge. Hydroxyapatite (HAp) was used to simulate microcalcifications. The contrast to noise ratio (CNRtc) of the subtracted images was calculated for both monoenergetic and polyenergetic X-ray beams. The optimum monoenergetic pair was 23/58 keV for the low and high energy, respectively, resulting in a minimum detectable microcalcification thickness of 100 μm. In the polyenergetic X-ray study, the optimal spectral combination was 40/70 kVp filtered with 100 μm cadmium and 1000 μm copper, respectively. In this case, the minimum detectable microcalcification thickness was 150 μm. The proposed dual energy method provides improved microcalcification detectability in breast imaging with mean glandular dose values within acceptable levels