By generating a synthetic CT image (sCT) directly from the MRI, the electron density can be calculated, and the CT examination can be excluded from the patient flow minimizing the risk of uncertainties in the registration. Basing the radiation treatment process solely on MR images is called MRI-only and is beneficial for the patient as it can provide more accurate radiation treatment than the standardised treatment with fewer CT examinations and possibly a more cost-effective radiation treatment process.  The conventional coils that are normally used in MRI for dose planning purpose cannot be placed directly on the patient as the outer body contour then can be deformed by these relatively heavy coils. The coils are therefore placed on a special holder which creates distance between the coil and the patient, this degrades the signal to noise ratio (SNR). The department for radiation treatment at Linköping University Hospital has access to a newly developed coil with so-called Air Technology. This type of coil is significantly lighter than the conventional ones and the idea is that this coil can be placed directly on the patient without causing deformation.  The aim of this project is to develop a software tool to validate an MRI-only workflow and to investigate if the radiation dose calculation based on sCT data differs from calculations based on CT data. Furthermore, to examine if the AIR coil has any effect on the body contour and the calculated dose.  For the evaluation of the AIR coil three similarity comparison methods were used, Hausdorff distance, Dice similarity coefficient (DSC) and Surface DSC. The result for the Hausdorff distance showed that eight out of eleven comparisons were within 4 mm difference, this corresponded good with Surface DSC where eight out of eleven had a result over 99% at a 3 mm tolerance. DSC measures gave above 98.5% for nine out of eleven of the comparisons.  The investigation on whether the radiation dose calculation differed was done using the dose- volume histogram statistics in Eclipse. A method calculating the gamma index was implemented in MICE. The results showed that nine out of ten gamma indexes had deviations that were within the same range. An explanation for why the results of one patient were not within the same range as the others could not be found and needs further investigations.

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Dans le domaine médical, l'informatisation des professions de santé et le développement du dossier médical personnel (DMP) entraîne une progression rapide du volume d'information médicale numérique. Le besoin de convertir et de manipuler toute ces informations sous une forme structurée constitue un enjeu majeur. C'est le point de départ de la mise au point d'outils d'interrogation appropriés pour lesquels, les méthodes issues du traitement automatique du langage naturel (TALN) semblent bien adaptées. Les travaux de cette thèse s'inscrivent dans le domaine de l'analyse de documents médicaux et traitent de la problématique de la représentation de l'information biomédicale (en particulier du domaine radiologique) et de son accès. Nous proposons de construire une base de connaissance dédiée à la radiologie à l'intérieur d'une base de connaissance générale (réseau lexico-sémantique JeuxDeMots). Nous montrons l'intérêt de l'hypothèse de non séparation entre les différents types de connaissances dans le cadre d'une analyse de documents. Cette hypothèse est que l'utilisation de connaissances générales, en plus de celles de spécialités, permet d'améliorer significativement l'analyse de documents médicaux.Au niveau du réseau lexico-sémantique, l'ajout manuel et automatisé des méta-informations sur les annotations (informations fréquentielles, de pertinences, etc) est particulièrement utile. Ce réseau combine poids et annotations sur des relations typées entre des termes et des concepts ainsi qu'un mécanisme d'inférence dont l'objet est d'améliorer la qualité et la couverture du réseau. Nous décrivons comment à partir d'informations sémantiques présentes dans le réseau, il est possible de définir une augmentation des index bruts construits pour chaque comptes rendus afin d'améliorer la recherche documentaire. Nous présentons, ensuite, une méthode d'extraction de relations sémantiques entre des termes ou concepts. Cette extraction est réalisée à l'aide de patrons linguistiques auxquels nous avons rajouté des contraintes sémantiques.Les résultats des évaluations montrent que l'hypothèse de non séparation entre les différents types de connaissances améliorent la pertinence de l'indexation. L'augmentation d'index permet une amélioration du rappel alors que les contraintes sémantiques améliorent la précision de l'extraction de relations. / In the medical field, the computerization of health professions and development of the personal medical file (DMP) results in a fast increase in the volume of medical digital information. The need to convert and manipulate all this information in a structured form is a major challenge. This is the starting point for the development of appropriate tools where the methods from the natural language processing (NLP) seem well suited.The work of this thesis are within the field of analysis of medical documents and address the issue of representation of biomedical information (especially the radiology area) and its access. We propose to build a knowledge base dedicated to radiology within a general knowledge base (lexical-semantic network JeuxDeMots). We show the interest of the hypothesis of no separation between different types of knowledge through a document analysis. This hypothesis is that the use of general knowledge, in addition to those specialties, significantly improves the analysis of medical documents.At the level of lexical-semantic network, manual and automated addition of meta information on annotations (frequency information, pertinence, etc.) is particularly useful. This network combines weight and annotations on typed relationships between terms and concepts as well as an inference mechanism which aims to improve quality and network coverage. We describe how from semantic information in the network, it is possible to define an increase in gross index built for each records to improve information retrieval. We present then a method of extracting semantic relationships between terms or concepts. This extraction is performed using lexical patterns to which we added semantic constraints.The results show that the hypothesis of no separation between different types of knowledge to improve the relevance of indexing. The index increase results in an improved return while semantic constraints improve the accuracy of the relationship extraction.

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No description available.

Bakgrund: Magnetresonanstomografi (MR) är associerat med olika risker relaterade till magnetfälten. Enligt patientsäkerhetslagen ska vårdpersonalen arbeta för patientens säkerhet och undvika vårdskador. Om vårdpersonal inte känner till risker med de olika magnetfälten kan detta leda till en brist i MR-säkerheten. Syfte: Att beskriva erfarenheter och upplevelser av MR-undersökningar och MR-säkerhet hos vårdpersonal som följer med patienter vid en MR-undersökning. Metod: En kvalitativ metod användes för denna studie med semi-strukturerade intervjuer som datainsamlingsmetod. Totalt deltog16 informanter från ett universitetssjukhus i Sverige i studien. Insamlade data analyserades med manifest innehållsanalys. Resultat: Resultatet visar att informanterna upplever att MR-undersökningar kräver mycket förberedelser för vårdpersonalen och innebär ofta lång undersökningstid. Informanternas erfarenhet av att medfölja till MR-undersökningar var generellt liten på grund av att det ofta var långt mellan undersökningstillfällena och att detta kan leda till glömska av vad som är tillåtet och inte tillåtet vid MR-kameran som medföljande vårdpersonal. Det uppkom av informanternas beskrivningar att metall utgör risker nära magnetkameran och att det finns risker för brännskador för patienter. Resultatet visade även att informanter litade på sig själva gällande MR-säkerhet men att det även fanns en önskan om att få ta del av mer utbildning i ämnet. Slutsats: Vårdpersonalens erfarenheter och upplevelser om MR-underökningar och MR- säkerhet visar att kunskap om risker med MR-undersökningar förekommer och att mycket förberedelser krävs. Erfarenheten av MR-undersökningar bland informanterna var liten och likaså kunskapen om MR-säkerhetsutbildning.

Many software companies today collect command usage data by monitoring and logging user interactions within their applications. This is not always utilised to its full potential, but with the use of state-of-the-art process mining techniques, this command usage log data can be used to gain insights about the users' workflows. These insights can then be used to improve the software application and boost user productivity and efficiency. One area where this might be especially relevant is within the radiology domain, where the radiology labour shortage renders every efficiency-improvement valuable. Connected to this, this thesis aimed to evaluate a number of process mining techniques on real radiology PACS command usage data from Sectra to identify which techniques might be useful for analysing user workflows. Three process discovery algorithms (Alpha, Heuristics, and Inductive Miner - infrequent) were used on two datasets and evaluated based on a number of quantitative metrics (fitness and simplicity) and qualitative aspects (interpretability and usefulness). The qualitative aspects of the resulting process models were assessed through interviews with domain experts at Sectra, and the Heuristics Miner was found to discover the most useful models that could be interpreted and analysed by domain experts, mainly due to its simpler process model notation. To reduce model complexity, three different filtering methods based on sequential pattern mining were evaluated as a pre-processing step before applying the discovery algorithms. This resulted in improvements for the Alpha and Inductive Miner - infrequent, although none of the methods improved the Heuristic Miner models against the baseline. Trace clustering was also explored to address model complexity with the aim of identifying trace execution variants. Several configurations of trace representation techniques and clustering algorithms were used, and the neural-network-based approaches, Word2Vec and Autoencoder, emerged as the alternatives that achieved the best scores in the clustering evaluation. A few clusters with well-separated trace execution variants were identified - although most clusters were still complex and dominated by similar events. Finally, a prototype application with integrated process mining concepts was created based on the findings from the previous interviews. This was then evaluated with domain experts at Sectra, with the aim of investigating what concepts are practically useful for assisting with domain analysis. The findings indicate a clear use case for such an application to analyse sequential relations and command usage patterns in PACS user workflows, providing a data-driven and on-demand approach for hypotheses testing. Simpler concepts like manual filtering and aggregation were found to be practically useful and prioritised by the domain experts, while the opinion was more divided on the automatic pre-processing methods.

Objectives. To identify treatment indications for symptomatic and asymptomatic Florid Cemento- Osseous Dysplasia in adult patients. To explore the relationship between clinical variables, demographics, and radiographic findings. Methods. A systematic review was conducted by an independent investigator using the electronic databases, PubMed, ProQuest, Embase, Web of Science, Dentistry and Oral Sciences Database (DOSS) and TRIP databases to identify cohort, retrospective, and cross-sectional studies on Florid Cemento-Osseous dysplasia treatment options in adults from 2001-2022. Inclusion criteria for this systematic review included: studies must be in English; open-access; published between 2001-2021. The PRISMA guidelines and Joanna Briggs Institute (JBI) Critical Appraisal checklist were used for reporting and quality assessment of each study. Results. From initial 122 studies, 11 fit the criteria and were analyzed for this systematic review. Black females were reported to have significant presentation for FCOD. Mean age of patients was 40 years old. Eight studies reported symptoms as clinical presentation of FCOD, making it the most common. Six studies reported swelling and three studies reported infection. Five studies recommended surgical treatment in symptomatic patients with disturbances around the lesions such as, presence of necrotic bone, secondary infection, or neoplasia. Treatment of asymptomatic FCOD or biopsies were contraindicated in all studies but one, while dental prophylaxis was recommended. Conclusion. For cases of Asymptomatic FCOD, dental prophylaxis and monitoring were the most common treatment options provided. According to existing literature, symptomatic FCOD may be treated through curettage, blood stimulation, or pulp vitality testing of specific areas with periapical inflammation. Continued dental prophylaxis and monitoring were the most common treatment options suggested. More research should be done using experimental and clinical trials to explore proper treatment options for symptomatic and asymptomatic FCOD to draw clear consensus. / Oral Biology

Bakgrund: 68Gallium- Prostataspecifikt membranantigen – Positronemissionstomografi/Datortomografi (68Ga-PSMA-PET/DT) är en metod för att undersöka patienter med prostatacancer och eventuella metastaser. Denna undersökningsmetod har gjort att fler patienter kan få en diagnos i ett tidigt skede. Det saknas studier i patientupplevelser kring denna undersökning. Syfte: Syftet med studien är att beskriva patienters upplevelse av en 68Ga-PSMA-PET/DT-undersökning från remiss till utförd bildtagning.  Metod: En empirisk kvalitativ intervjustudie med semistrukturerade intervjufrågor genomfördes med 12 patienter. Resultatet analyserades med en induktiv kvalitativ innehållsanalys. Resultat: Resultatet visade att de flesta som intervjuades upplevde att de var välinformerade både muntligt från remitterande läkare, kallelse och den muntliga informationen som gavs under undersökningen. Majoriteten av patienterna upplevde inget obehag eller oro kring de olika momenten av undersökningen. Det framkom att muntlig information gällande risker med strålning till allmänheten inte givits till alla patienterna och studien fann att det fanns förbättringsbehov inom det området. Några upplevde att det var obehagligt att behöva ta diuretika, dricka vatten samt att ligga länge i PET/DT- kameran. Några av patienterna tyckte att undersökningen tog lång tid.  Slutsats: Studien visade att de flesta av patienterna kände sig välinformerade och väl bemötta. Studien fann däremot att det finns förbättringsområden vad gäller information efter undersökningen. Några patienter upplevde vissa förberedande moment som ansträngande, men en majoritet upplevde inga problem med undersökningen.

No description available.