In study 1, thirty-eight healthy controls were used for optimization of the method. Fifteen patients with progressive supranuclear palsy and an equal number of age-matched healthy controls underwent diffusion tensor MRI and were then investigated and compared groupwise. It was shown that tractography analyses may preferably be performed regionally, such as along the tracts or in different segments of the tracts. Normalization of white matter tracts can be performed using anatomical landmarks. In study 2, 104 males and 153 females in the age interval 13 to 84 years of age participated as healthy individuals in order to investigate age-related changes with diffusion tensor MRI. It was shown that spatially differences in age-related changes exist between subdivided segments within white matter tracts. The aging processes within the CB and the IFO vary regionally. In study 3, 38 human brains were used for investigation of the white matter tract inferior longitudinal fasciculus (ILF) and its subcomponents. Of these, white matter anatomical dissection was performed in 14 post-mortem normal human brains. The remaining 24 brains were investigated in vivo with diffusion tensor MRI in healthy individuals. It was validated that fibers of the ILF in the occipito-temporal region have a clear, constant and detailed organisation. The anatomical connectivity pattern, and quantitative differences between the ILF subcomponents, confirmed a pivotal role of the ILF. In study 4, 12 patients with iNPH were included in the study and examined with diffusion tensor at three time points. For comparison, 12 healthy controls, matched by gender and age were also included. Controls were examined with MRI only once. It was shown that DTI measures differ significantly between patients with iNPH and healthy controls. DTI measures of the CC, the CST and the SLF, correlated to changes in clinical symptoms after shunt surgery. Deeper knowledge about functions of the brain increases possibilities to take advantages from DTI analyses with tractography.

Accurate measures of both clinical image quality and patient radiation risk are needed for successful optimisation of medical imaging with ionising radiation. Optimisation in diagnostic radiology means finding the image acquisition technique that maximises the perceived information content and minimises the radiation risk or keeps it at a reasonably low level. The assessment of image quality depends on the diagnostic task and may in addition to system and quantum noise also be hampered by overlying projected anatomy. The main objective of this thesis is to develop methods for assessment of image quality in simulations of projection radiography. In this thesis, image quality is quantified by modelling the whole x‐ray imaging system including the x‐ray tube, patient, anti‐scatter device, image detector and the observer. This is accomplished by using Monte Carlo (MC) simulation methods that allow simultaneous estimates of measures of image quality and patient dose. Measures of image quality include the signal‐to‐noise‐ratio, SNR, of pathologic lesions and radiation risk is estimated by using organ doses to calculate the effective dose. Based on high‐resolution anthropomorphic phantoms, synthetic radiographs were calculated and used for assessing image quality with model‐observers (Laguerre‐Gauss (LG) Hotelling observer) that mimic real, human observers. Breast and particularly chest imaging were selected as study cases as these are particularly challenging for the radiologists. In chest imaging the optimal tube voltage in detecting lung lesions was investigated in terms of their SNR and the contrast of the lesions relative to the ribs. It was found that the choice of tube voltage depends on whether SNR of the lesion or the interfering projected anatomy (i.e. the ribs) is most important for detection. The Laguerre‐Gauss (LG) Hotelling observer is influenced by the projected anatomical background and includes this into its figure‐of‐merit, SNRhot,LG. The LG‐observer was found to be a better model of the radiologist than the ideal observer that only includes the quantum noise in its analysis. The measures of image quality derived from our model are found to correlate relatively well with the radiologist’s assessment of image quality. Therefore MC simulations can be a valuable and an efficient tool in the search for dose‐efficient imaging systems and image acquisition schemes.

No description available.

Background: MRI- safety education is an important aspect from a work environment perspective and patient perspective, to avoid harmful and deadly accidents. Aim: The aim of the study was at two hospitals investigate if the radiographers feels that the MRI safety education is enough to work safe in MRI environment. The study’s aim was also to investigate in what form MRI-safety is preformed and see if there is a difference between hospital A and B. The study was addressed to radiographers who works with MRI and radiographers who works with other modalities. This study also investigates if radiographers knows about guidelines for other staff who works regularly at MRI and if the radiographers feel that this education is enough. Method: The study is an empirical quantitative inquiry study with qualitative analysis. The inquiry was own constructed to answer the study´s aims. Forty radiographers from two hospitals ware included. Results: The results showed 53% of the participants have not attended any education about MRI-safety through their current employer. 65 % of the participants who attended education claimed the education was enough for them to work in a MRI-safe way. 52% of the participants experience that other workmen’s/clinicians don’t have enough education to create an MRI safe environment. A significant different in form of education was found in web education that were more frequent at hospital B. Conclusion: The results shows that majority of the participant haven’t had any safety education from their current employer. However, the ones who did found it to be enough to work in an MRI-safe way. The participants comments showed that MR-safety education always a current subject in need of repetition and development. / Bakgrund: Magnetisk Resonanstomografi (MR)- säkerhetsutbildning är en viktig aspekt ur både arbetsmiljösynpunkt och ur patientperspektiv för att undvika skadliga och dödliga olyckor. Syfte: Studien syftade till att på två sjukhus undersöka om röntgensjuksköterskorna upplever att utbildningen är tillräcklig för att arbeta säkert i MR-miljö. Studien syftade också till att undersöka på vilket sätt säkerhetsutbildning inom MR sker samt jämföra skillnaden mellan sjukhus A och B. Studien riktade sig till röntgensjuksköterskor som arbetar med MR, samt övriga röntgensjuksköterskor på röntgenavdelningen. I studien undersöktes även om röntgensjuksköterskorna känner till om det finns riktlinjer för annan personal/sjukvårdspersonal som vistas i MR-miljö samt om röntgensjuksköterskan upplever den utbildningen som tillräcklig. Metod: En empirisk kvantitativ enkätstudie med inslag av kvalitativ analys. Enkätfrågorna egenkonstruerades för att besvara studiens syften. Fyrtio röntgensjuksköterskor från två sjukhus inkluderades. Resultat: Resultatet visade att 53% av deltagarna inte genomgått någon MR-säkerhetsutbildning via nuvarande arbetsgivare. Av deltagarna som hade genomgått en sådan utbildning uppgav 65% att den var tillräcklig för att arbeta MR-säkert. I studien upplevde 52% att övrig personal/sjukvårdspersonal inte var tillräckligt utbildad för att skapa en säker MR-miljö. En signifikant skillnad mellan sjukhusen visades vid utbildningsform webbutbildning som var mer förekommande på sjukhus B.  Slutsats: Resultatet av studien visade att majoriteten av deltagarna inte hade genomgått någon MR-säkerhetsutbildning via nuvarande arbetsgivare, däremot upplevde de som hade gjort det att utbildningen var tillräcklig för att kunna arbeta MR-säkert. Deltagarnas egna synpunkter visar att MR-säkerhetsutbildning är något som ständigt är aktuellt och alltid behöver upprepas samt uppdateras.

Bakgrund: Våld mot kvinnor är ett världsproblem. Vårdpersonal har ingen anmälningsplikt vid misstanke av våld mot vuxna. Vikten att lyfta fram mest förekommande tecken i samband med våld i nära relation anses viktigt för att ge vårdsökanden adekvat hjälp och stöd. Syfte: Syftet med studien var att belysa typiska tecken på våld i nära relationer på kvinnor som röntgensjuksköterskan kan upptäcka inom  yrkesrollen Metod: En litteraturstudie med kvalitativ ansats genomfördes. Databaserna Cinahl, Medline och PsyckINFO har använts för sökning vilket resulterade i 16 artiklar. Efter analys av dessa artiklar skapades två huvudkategorier med subkategorier. Resultat: Våld relaterade situationer börjar ofta med psykiskt våld för att senare utvecklas till olika grad av fysiskt våld. Skadorna sker över hela kroppen men mest runt huvud, ansikte och hals området. Det har visat sig att strypning är en av bakomliggande orsaker till många våldsrelaterade dödsfall. Två grupper som framkom var synliga och dolda tecken. Diskussion: Trots satsningar fortsätter våld mot kvinnor. För att bekämpa detta är det högst nödvändigt att myndigheter samarbetar och tar ansvar. Slutsats: Den våldutsatte befinner sig oftast i chocksituation och är känslig mot omgivningen. Korrekt omhändertagande är viktigt för att minska negativa känslor. / Abstract: Signs of interpersonal violence towards women- what radiographer can detect Background: Domestic violence is a worldwide problem. Healthcare professionals in Sweden has no responsibility to report domestic violence against adults. It is important to raise awareness about common signs of domestic violence and give healthcare seekers adequate help. Purpose:  The aim is to illustrate typical signs of domestic violence against women which radiographers can discover in the profession. Method: A literature research in databases Cinahl, Medline and Psykinfo was used to find 16 scientific articles. After analysing articles, two categories, with subcategories were created. Results: Violence-related injuries often start with mental violence and develop into different degrees of physical violence. Injuries appear in all parts of the body, studies have shown that the head, face and neck region are most usually affected. Also known is that strangulation is the cause of many violent related deaths. Discussion: Violence against women still continues. To overcome this problem, it is necessary for all involved authorities to cooperate and take responsibility. Conclusion: The victim is usually in shock and sensitive towards the environment. Proper care is important to reduce the negative emotions the victim may encounter.

Après l’incorporation de radionucléides dans l’organisme, l’imagerie quantitative en médecine nucléaire et l’anthroporadiométrie sont utilisés pour quantifier l’activité retenue. L’étalonnage de ces systèmes in vivo peut être amélioré afin de tenir en compte de la variabilité individuelle. En vue d’optimiser la mesure de l’activité retenue, des fantômes d’étalonnage innovants ont été réalisés par impression 3D. L’infographie 3D a été utilisée pour la conception, en parallèle avec un travail d’ingénierie permettant l’inclusion de radionucléides et l’adaptation aux besoins des utilisateurs. Un jeu de fantômes thyroïdiens adapté à l’âge a été développé et utilisé pour améliorer la mesure anthroporadiométrique thyroïdienne des enfants. À la suite d’une étude systématique, les coefficients d’étalonnage des installations de routine et de crise de l’IRSN ont été déterminés pour l’adulte et les enfants de 5, 10 et 15 ans. Un fantôme thyroïdien pathologique a été développé en plus du jeu de fantômes thyroïdiens dédié à la crise pour améliorer la mesure de fixation thyroïdienne en médecine nucléaire. Une étude multicentrique a été réalisée pour optimiser l’étalonnage afin de mieux personnaliser le traitement des pathologies bénignes de la thyroïde. Pour l’anthroporadiométrie pulmonaire, une famille de fantômes de poitrine a été développée pour améliorer la surveillance des travailleuses du nucléaire. Finalement, ce travail de recherche a permis de développer des fantômes adaptés aux besoins et de démontrer leur utilité pour la quantification de l’activité en dosimétrie interne. / Following the incorporation of radionuclides in the body, quantitative imaging in nuclear medicine and in vivo spectrometry measurements are used to quantify the retained activity. The calibration of these in vivo systems can be improved to take account of individual variability. To optimize the measurements of the activity retained, innovative calibration phantoms were created and manufactured by 3D printing. 3D computer graphics were used for the design, coupled with an engineering work allowing the inclusion of radionuclides and the fit to users’ needs. A set of age-specific thyroid phantoms has been developed and used to improve the thyroid in vivo measurement of children. Following a systematic study, the calibration coefficients for IRSN emergency and routine installations were determined for adults and 5, 10 and 15 year old children. A pathological thyroid phantom has been developed in addition to the set of thyroid phantoms dedicated to the emergency to improve the thyroid uptake measurement in nuclear medicine. A multicentre study was carried out to optimize the calibration so that treatment of thyroid benign diseases moves towards a better personalization. For lung in vivo measurement, a set of breast phantoms has been developed to improve the monitoring of female workers. Finally, this research work has allowed developing several phantoms adapted to the needs and their usefulness was proven for the quantification of the activity in internal dosimetry.

Bakgrund: Hög kompetens hos röntgensjuksköterskorna är essentiellt för att upprätthålla hög patient- samt personalsäkerhet inom strålskydd. Ett flertal studier har undersökt röntgensjuksköterskans kunskap och behov av vidareutbildning ur olika aspekter. Syfte: Studiens syfte var att undersöka hur röntgensjuksköterskor på två sjukhus upplevde sina kunskaper i strålsäkerhet, tillgång till skyddsutrustning och behovet av vidareutbildning. Metod: Studien genomfördes som en kvalitativ semistrukturerad intervjustudie med tio intervjuer. Analysen för studien gjordes i form av en kvalitativ innehållsanalys med en deduktiv form. Resultat: Resultaten av studien visade att det fanns skillnad mellan röntgensjuksköterskans säkerhetskunskap och hur rutiner efterlevdes på arbetsplatsen inom strålsäkerhetsområdet. Även om de flesta initialt uppskattade sin kunskap till god eller tillräcklig så fanns skillnader som till största delen grundades på vilket sjukhus informanten arbetade på. När det gällde grundläggande säkerhetsutrustning fanns det en skillnad mellan sjukhusen, både när det gällde tillgång och lättillgänglighet. Tillgången till vidareutbildning skilde sig också mellan sjukhusen. Slutsats: Röntgensjuksköterskors förmåga att arbeta patientsäkert ur strålskyddssynpunkt var sammankopplat med deras kunskap i strålsäkerhet och arbetsplatsens tillgång till strålningsförebyggande hjälpmedel. Studien visade på skillnader mellan de två röntgenavdelningar som undersöktes främst när det gällde tillgång på regelbunden utbildning inom strålsäkerhet och tillgången på strålförebyggande utrustning, men också användandet av utrustningen i det dagliga arbetet. / Background: The radiographers’ competences in the field of radiation protection is essential in ensuring a high standard of patient and staff safety. Several studies have examined various aspects effecting the radiographers’ knowledge and need for further training. Aim: The aim of this study was to investigate how radiographers from two hospitals experienced their knowledge of radiation safety, access to protective equipment and the need for further training. Method: The study was conducted as a qualitative semi-structured interview study with ten radiographers participating. The analysis for the study was done in the form of a qualitative content analysis using a deductive form. Results: The study found a difference between the radiographers’ knowledge in radiation safety and how radiation safety routines were performed. Although most initially estimated their knowledge to be good or sufficient, there were some differences, based on which hospital the radiographers’ worked at. When it came to basic safety equipment there where differences noted between the hospitals, both in terms of access and availability. The availability of continued education varied significantly between the two hospitals. Conclusion: The ability of radiographers to work patient-safe, from a radiation protection standpoint, is linked to their knowledge of radiation safety and the workplace's access to radiation protection equipment. The study showed differences between the two radiography departments that were examined. Differences were noted mainly in terms of access to continued radiation safety education, the availability of radiation protection equipment and the use of protective equipment in daily work.

Background One of the most used treatments for hyperthyroidism, is therapy with radioactive iodine (131I), which is accumulated in the thyroid gland. To determine the activity of 131I to be administered for a certain absorbed dose, the volume of the gland is of great importance but the historically used methods for estimating the functional volume of the gland are based on large approximations. The use of SPECT images enables increased accuracy of functional volume determination. However, there is a need for more realistic phantom studies and improved image segmentation. Aim The aim of this thesis was to find a robust method for image segmentation of the thyroid gland that could adapt to various object sizes and contrasts. The aim was also to develop an accessible and flexible 3D thyroid phantom for measurements and optimisation of parameter settings. Materials and Methods Thyroid phantoms made from playdough loaded with 99mTcO4-, were placed in a neck phantom filled with 99mTcO4- solution of various concentration. SPECT and CT acquisitions of the phantoms were performed and the SPECT images were segmented using thresholding and region growing algorithms. The thresholds in the segmentation algorithms were optimised by minimisation of cost functions consisting of Dice score, against the CT-volume, and relative SPECT volume. To find thresholds that could be used on all phantom volumes and image backgrounds, two overall cost functions were optimised for high and low backgrounds respectively. The optimised thresholds were validated on another set of playdough phantoms. They were also used on a simpler plastic can phantom for comparison of the performance relative to the method used in the clinic today. Results The optimised thresholds showed a substantial divergence between the measurements, ranging from 40 to 58 % for the thresholding algorithm and from 8 to 19 % for the region growing algorithm. The overall optimised thresholds were 55 and 48 % for high and low image backgrounds for the thresholding algorithm which was selected for the validation measurements due to its lower overall cost function and high stability. The developed method indicated a higher accuracy in functional volume determination of the thyroid gland than the standard method used. Conclusions An image segmentation method for functional volume determination of the thyroid gland, that can adapt to image contrast, was developed in this thesis. The method indicates an improved accuracy for functional volume determination of thyroid glands, but more experiments would need to be conducted. The developed thyroid phantoms enable further optimisation of image segmentation parameters for various object sizes, contrasts and shapes. The results indicate that thresholds deduced from simpler phantoms may be too uncertain which might lead to overtreatment of hyperthyroidism with 131I. It was also indicated that thresholding is more suitable than region growing for image segmentation of SPECT images.

Introduktion: Alla röntgenundersökningar med joniserande strålning ska vara berättigade och optimerade. Detta kräver röntgenremisser av god kvalité. Syfte: Syftet med litteraturöversikten var att beskriva faktorer som har påverkan i röntgenremissens berättigandeprocess. Metod: En allmän litteraturöversikt baserad på kvantitativa studier som kvalitetsgranskats. Resultat: Resultatet presenteras i fem kategorier: berättigade och oberättigade röntgenundersökningar, avsaknad av klinisk information, användning av riktlinjer, införande av intervention och röntgenremissens utformning. Slutsats: Röntgenremissers kvalité har betydelse i berättigandeprocessen. Antalet oberättigade röntgenundersökningar minskar genom ökad kunskap vilket gör utbildning för remitterande läkare till en nyckelfaktor. Detta leder till säkrare sjukvård där patienter inte utsätts för onödig joniserande strålning. / Introduction: All x-ray examinations with ionizing radiation must be justified and optimized. This requires radiology referral of good quality. Aim: The aim of the study was to describe factors that affect the process of justification in radiology referrals. Method: A general literature review based on quantitative studies that have been verified based on its credibility. Result: The results are presented in five categories: justified and unjustified x-ray examinations, lack of clinical information, use of guidelines, introduction of intervention and the design of the radiology referral. Conclusion: The quality of the radiology referral has significance in the process of justification. Number of unjustified x-ray examinations are reduced through increased knowledge, which makes education for referring physicians a keyfactor. This leads to safer healthcare where patients are not exposed to unnecessary ionizing radiation.

Bakgrund: Skelettscintigrafi är en nuklearmedicinsk undersökning. Undersökningen är den mest använda nukleardiagnostiska metoden och den genomförs ofta som en helkroppsundersökning. För att undersökningen ska kunna erhålla sin diagnostiska kvalitet, samt följa strålsäkerhetsmyndighetens rekommendationer behövs det mer kännedom till hur optimeringen ska följa as low as reasonably achievable (ALARA). Studiens syfte var att optimera patientstråldos samt att undersöka hur injicerad aktivitet kan anpassas efter patientens specifika parametrar. Metod: Studiegruppen bestod av 85 patienter som genomgick skelettscintigrafier vid Central sjukhuset i Karlstad, från perioden februari-april 2020. Resultat: Visade att både ålder och vikt är patientspecifika variabler som borde tas till betraktning vid bestämning av injicerad strålningsdos. Konklusionen: För att optimera undersökningen för varje patient bör injicerad aktivitet anpassas efter både kroppsvikt och ålder. Fler studier där andra parametrar undersöks måste genomföras. / Background: Bone scintigraphy is a nuclear medicine procedure. It is the most used nuclear diagnostic method and provides the opportunity to perform a full-body examination. For the method to retain its diagnostic quality, and to follow the recommendations of the Radiation Safety Authority, more knowledge is required on how the optimization should follow as low as reasonably achievable (ALARA). The purpose of the study was to optimize patient radiation dose and to investigate how the injected activity can be adapted to patient-specific parameters. Method: The study group consisted of 85 patients who underwent bone scintigraphy at the Central Hospital in Karlstad, from the period February-April 2020. Result: Showed that age and weight are patient-specific variables that should be considered when determining injected radiation dose. Conclusion: To optimize the examination for each patient, injected activity should be adjusted according to the patient’s body weight and age. More studies in where other parameters are investigated must be carried out.