22 research outputs found
Impact of gonad shielding for AP pelvis on dose and image quality on different female sizes : a phantom study
Introduction
In clinical practice AP pelvis standard protocols are suitable for average size patients. However, as the average body size has increased over the past decades, radiographers have had to improve their practice in order to ensure that adequate image quality with minimal radiation dose to the patient is achieved. Gonad shielding has been found to be an effective way to reduce the radiation dose to the ovaries. However, the effect of increased body size, or fat thickness, in combination with gonad shielding is unclear.
The goal of the study was to investigate the impact of gonad shielding in a phantom of adult female stature with increasing fat thicknesses on SNR (as a measure for image quality) and dose for AP pelvis examination.
Methods
An adult Alderson female pelvis phantom was imaged with a variety of fat thickness categories as a representation of increasing BMI. 72 images were acquired using both AEC and manual exposure with and without gonad shielding. The radiation dose to the ovaries was measured using a MOSFET system. The relationship between fat thickness, SNR and dose when the AP pelvis was performed with and without shielding was investigated using the Wilcoxon signed rank test. P-values < 0.05 were considered to be statistically significant.
Results
Ovary dose and SNR remained constant despite the use of gonad shielding while introducing fat layers.
Conclusion
The ovary dose did not increase with an increase of fat thickness and the image quality was not altered.
Implications for practice
Based on this phantom study it can be suggested that obese patients can expect the same image quality as average patients while respecting ALARA principle when using adequate protocols
Relationships between renal cytoplasmic and nuclear aldosterone-receptors
Relationships between renal cytoplasmic and nuclear aldosteronereceptors.Three 3H-aldosterone receptor complexes have been recovered from rat kidneys: 1) cytosol (high speed supernatants), 2) Tris-soluble nuclear (obtained by an osmotic shock procedure), and 3) chromatin-bound (prepared by extracting post-shock nuclei with 0.4 M KCl).Glycerol density gradient analyses of cytosol labelled in vivo or in vitro with 3H-aldosterone yielded two specific peaks -4.5S and 8.5S.These peaks were sensitive to salt concentration; 0.4 M KCl shifted the 8.5S to 4.5S and the addition of Ca++ (6 mM) resulted in a further shift to 3.5S.The Tris-soluble nuclear species sedimented at 3S and the chromatin-bound species at 4S.The time-course of generation of the 3H-aldosterone-labelled cytosol and nuclear receptor species was studied in vivo and in vitro by tissue slice and reconstitution methods.The results obtained are consistent with a three-step mechanism: cytosol (8.5S or 4.5S)â Tris-soluble nuclear (3S)â chromatin-bound (4S).Alternatively, the 3S and 4S complexes may be attached to independent nuclear sites.The formation of the chromatin-bound species was temperature sensitive and failed to form at 0°C.Pre-treatment with DNase but not RNase impaired the generation of both the Tris-soluble nuclear and chromatin-bound species.These results imply a close association between nuclear aldosterone-receptor complexes and intact DNA
Religious socialisation and fertility: transition to third birth in the Netherlands
Although previous studies have demonstrated that religious people in Europe have larger families, the role played by religious socialisation in the context of contemporary fertility behaviour has not yet been analysed in detail. This contribution specifically looks at the interrelation between religious socialisation and current religiosity and their impact on the transition to the third child for Dutch women. It is based on data of the first wave of the Netherlands Kinship Panel Study (2002â2004) and uses event history analysis. The transitions to first, second and third birth are modelled jointly with a control for unobserved heterogeneity. The findings provide evidence for an impact of womenâs current church attendance as well as religious socialisation measured by their fathersâ religious affiliation, when they were teenagers. A religious family background remains influential even when a woman has stopped attending church. The effects of religious indicators strengthen over cohorts. Moreover, the combined religious make-up of the respondentâs parents also significantly determines the progression to the third child.Sâil est bien Ă©tabli que les croyants en Europe ont plus dâenfants que les autres, le rĂŽle de la socialisation religieuse dans le contexte de la fĂ©conditĂ© contemporaine nâa pas encore Ă©tĂ© analysĂ© Ă ce jour. Cette Ă©tude sâintĂ©resse au lien entre la socialisation religieuse et la religiositĂ© actuelle, et Ă leur impact sur la probabilitĂ© dâagrandissement de deux Ă trois enfants de la descendance des femmes nĂ©erlandaises. Les donnĂ©es exploitĂ©es sont celles de la premiĂšre vague du Panel NĂ©erlandais dâEtude de la ParentĂ© (the Netherlands Kinship Panel Study, 2002â2004). A lâaide des techniques de lâanalyse des biographies, les probabilitĂ©s dâagrandissement de rang 1, rang 2 et rang 3 ont Ă©tĂ© modĂ©lisĂ©es de façon conjointe, en contrĂŽlant lâhĂ©tĂ©rogĂ©nĂ©itĂ© non observĂ©e. Les rĂ©sultats mettent en Ă©vidence lâimpact de la frĂ©quentation actuelle de lâĂ©glise par les femmes et de leur socialisation religieuse, mesurĂ©e par lâappartenance religieuse de leur pĂšre quand elles Ă©taient adolescentes. Il apparaĂźt que la religiositĂ© du contexte familial exerce une influence, mĂȘme quand la femme ne frĂ©quente plus lâĂ©glise, et que les effets des indicateurs de pratique religieuse se renforcent dâune gĂ©nĂ©ration Ă lâautre. Enfin, lâappartenance religieuse conjointe des parents de la femme dĂ©termine significativement la probabilitĂ© dâavoir un troisiĂšme enfant
Challenges for IT-Enabled Formative Assessment of Complex 21st Century Skills
In this article, we identify and examine opportunities for formative assessment provided by information technologies (IT) and the challenges which these opportunities present. We address some of these challenges by examining key aspects of assessment processes that can be facilitated by IT: datafication of learning; feedback and scaffolding; peer assessment and peer feedback. We then consider how these processes may be applied in relation to the assessment of horizontal, general complex 21st century skills (21st CS), which are still proving challenging to incorporate into curricula as well as to assess. 21st CS such as creativity, complex problem solving, communication, collaboration and self-regulated learning contain complex constructs incorporating motivational and affective components. Our analysis has enabled us to make recommendations for policy, practice and further research. While there is currently much interest in and some progress towards the development of learning/assessment analytics for assessing 21st CS, the complexity of assessing such skills, together with the need to include affective aspects means that using IT-enabled techniques will need to be combined with more traditional methods of teacher assessment as well as peer assessment for some time to come. Therefore learners, teachers and school leaders must learn how to manage the greater variety of sorts and sources of feedback including resolving tensions of inconsistent feedback from different sources
OPTIMAX 2017 : radiation dose, image quality optimisation,the use of new technology in medical imaging
This year OPTIMAX settled in Oslo. After the successof previous years, we are proud to present the fourthEbook. As in previous years, the group was madeup of PhD-, MSc- and BSc students as well astutors from the seven European partner universities.Professional mix was drawn from medical physics/physics and radiography. OPTIMAX 2017 was partlyfunded by the partner universities and partly by theparticipants. Two students from South Africa and twofrom Brazil were invited by Hanze UAS (Groningen)and ESTeSL (Lisbon) summer school includedlectures and group projects in which experimentalresearch was conducted in four teams. Four research projects were performed with a focuson radiation dose optimization and image quality,namely: Possible dose reduction for pediatric patientsfor conventional radiology; Can the tube voltage belowered with the use of direct-conversion flat paneldetector system?; Impact of body size and kV in chestradiography; Quantity assessment on Image quality ofCBCT images of head phantom with implants of metaland ceramic objects.The last day of OPTIMAX 2017there was a poster session and a conference, in whichthe research teams presented their posters and oralpresentations. This book comprises of two sections, the first twochapters concern generic background informationabout international teamwork during the OPTIMAXsummerschool. The next chapters with theory on which the researchprojects were built. The second section containsthe research papers of the four research projects.Two research papers, Can the tube voltage belowered with the use of direct-conversion flat-paneldetector system? And Impact of body size and kV inchest radiography: Experimental receiver operatingcharacteristic analysis using a Multipurpose ChestPhantom âLungmanâ have been accepted for the ECRconference, Vienna, 2018 as oral presentations
Socialisation Religieuse et FĂ©conditĂ©: LâarrivĂ©e du TroisiĂšme Enfant aux Pays-Bas
Onkoplastische Rekonstruktion mit Fibula pro Tibia nach Resektion eines Marjolin-Ulcus am Unterschenkel - eine Fallvorstellung
Onkoplastische Rekonstruktion mit Fibula pro Tibia nach Resektion eines Marjolin-Ulcus am Unterschenkel - eine Fallvorstellung
Guest Editorial: OPTIMAX 2013
In 2012 we were awarded an Erasmus Intensive Programme grant to facilitate OPTIMAX 2013, a three week duration residential summer school held within the UK during August 2013. The summer school helped to further develop student radiographer skills in optimising x-radiation dose and image quality. With a major emphasis on visual techniques to determine image quality, lesion visibility, lesion detection performance and physical measures of image quality (eg signal to noise ratio (SNR)) we conducted controlled laboratory experiments on phantoms using Computed Radiography, CT and Full Field Digital Mammography. Mathematical modelling was used for radiation dose estimation. Sixty seven people from 5 European countries participated. This included 49 PhD, MSc and BSc students. Discipline areas included radiography, physics, biomedical science and nuclear medicine