Convolution neural networks have achieved a state of the art accuracy for multi-class segmentation in biomedical image science. In this thesis, a 2-Stage binary 2D UNet and MultiResUNet are used to segment the 3D cardiac CT Volumes. 3D volumes have been sliced into 2D images. The 2D networks learned to classify the pixels by transforming the information about the segmentation into latent feature space in a contracting path and upsampling them to semantic segmentation in an expanding path. The network trained on diastole and systole timestamp volumes will be able to handle much more extreme morphological differences between the subjects. Evaluation of the results is based on the Dice coefficient as a segmentation metric. The thesis work also explores the impact of the various loss function in image segmentation for the imbalanced dataset. Results show that2-Stage binary UNet has higher performance than MultiResUnet considering segmentation done in all planes. In this work, Convolution neural network prediction uncertainty is estimated using Monte Carlo dropout estimation and it shows that 2-Stage Binary UNet has lower prediction uncertainty than MultiResUNet.

Bakgrund Magnetresonanstomografi undersökningar blir mer frekventa och därmed ökar användningen av gadoliniumbaserade kontrastmedel. Dock är gadoliniumretention ett relativt nyupptäckt fenomen och dess påverkan är fortfarande relativt okänt. Syfte Syftet med denna litteraturstudie är att få en djupare förståelse om vad gadoliniumretention är och dess inverkan på människokroppen, samt vilka implementeringar röntgensjuksköterskorkan behöva göra för att anpassa vården efter ny forskning inom området. Metod Denna studie är en systematisk litteraturstudie. Datainsamlingen har gjorts via databaserna PubMed och CINAHL. Endast vetenskapliga artiklar som uppfyllt inklusionskriterierna, exempelvis att de är peer-reviewed och primärpublicerade, har inkluderats. De artiklar som har besvarat frågeställningarna har kvalitetsgranskats och sedan har artiklarna som uppnådde medel eller hög kvalitet analyserats. Resultat Resultatet av denna studie visar att ackumulerad gadoliniumretention kan uppstå efterupprepade administreringar av gadoliniumbaserade kontrastmedel. Inga negativa biverkningar hos människokroppen har påvisats. För att minska risken för gadoliniumretention rekommenderar flera studier att minska kontrastmedelsdoser och vara varsam vid administrering. Slutsats Gadoliniumretention kan ses som förhöjd signalintensitet främst i dentate nucleus och globuspallidus i hjärnan efter upprepade administreringar av gadoliniumkontrastmedel. Dess påverkan på människokroppen är fortfarande okänd och mer forskning behövs om hurröntgensjuksköterskor kan anpassa vården därefter. / Background Magnetic resonance imaging exams is becoming more common and therefore the use of gadolinium-based contrast media increases. However, gadolinium retention is a relatively newly discovered phenomenon, and its impact on the human body is still unknown. Purpose The purpose of this study is to obtain a deeper understanding of what gadolinium retention is and how it affects the human body, and which implementations radiographers may have to do to adapt the care according to new research within the field. Method This study is a systematic literary review. The data collection was made from the databases PubMed and CINAHL. Only scientific studies that fulfilled the inclusion criteria, for example that they were peer-reviewed and primary published, were included. The articles that answered the questions were quality reviewed and the articles that achieved medium or high quality were analysed. Results The result of this study shows thar accumulated gadoliniumretention can arise after repeated administrations of gadolinium-based contrast media. No adverse effects in the human body have been demonstrated. To reduce the risk of accumulating gadoliniumretention several studies recommend reducing the dosage and to be cautious when administrating. Conclusion Gadoliniumretention can be seen as an increased signal intensity, mainly in dentate nucleus and globus palladius in the human brain after multiple administration of gadolinium-based contrast media. Its adverse effects on the human body are still unknown and more research is needed on how radiographer can adapt the care thereafter.

Prostate cancer (PCa) is the second most common cancer diagnosis for men and the fifth leading cause of cancer-related death worldwide. A common treatment strategy for PCa is external beam radiation therapy (EBRT), where high doses of radiation are used to kill cancer cells. Recent developments in RT include maintaining acceptable side effects during intensified treatment over fewer treatment occasions (hypofractionation) and boosting the level of radiation to the gross tumor volume (GTV) visible on multiparametric magnetic resonance imaging (mpMRI) and positron emission tomography (PET). Without a histopathological (HP) reference, the dose distribution cannot be compared to the varying grades of aggressivity within the cancer, known as ISUP grade groups (IGGs). The aim of this master thesis project was to explore the dose distribution over IGGs using a gold standard HP reference and investigate the mitigating effects of rectal spacers, following a hypofractionated RT schedule with focal boosts. The dataset consists of 15 patients, planned for radical prostatectomy. These patients harbored high-risk disease (IGG ≥ 4) in the GTV. HP evaluations following surgery resulted in physical slices of the prostate, showing the location and IGG of lesions. EBRT treatment plans that combined an ultra-hypofractionation strategy with a boost to the GTV were made. The dose distributions were evaluated by dose volume histograms (DVHs) over the target volumes, organs at risks (OARs) and the lesions. Robust evaluations of targets and OARs were performed by recalculating doses following translations of the patient by 2 mm in all directions. Similarly, lesions were shifted by 2 mm in all directions with respect to the nominal dose plan to estimate the sensitivity to motion. The effects of the translations were assessed by examining the impact on the DVHs and percentage of passed clinical goals. Two viable dose plans for each patient were produced, one for a 10 mm spacer and one for 8 mm. Both plans fulfill all rectum goals. For the 10 mm plan, the average median dose (D50) was greater than the prescribed prostate dose (42.7 Gy) for all IGGs by atleast 1.1 Gy. The D50 of the higher grades (IGG 3, 4 and 5) were 47.5, 46.4 and 48.7 Gy, meaning that they were closer to the desired GTV dose 49.0 Gy than the prescribed prostate dose. This thesis project showed that it is possible to reach high GTV doses while sparing the OARs and that the higher IGGs received a higher dose than the lower grades. Examining rectal dose depending on different spacer thicknesses allowed us to recommend a spacer thickness that is safe to use, which can provide increased patient comfort while saving time and resources.

Nuklearmedicin är en specialitet där Flour18-fluorodeoxyglukos positronemissionstomografi/datortomografi (18F-FDG PET/DT) är en vanligt förekommande undersökning. Den vanligaste indikationen för att genomgå undersökningen är misstänkt eller känd cancer. Syfte: Syftet var att studera patienters upplevelse av information i samband med en 18F-FDG PET/DT-undersökning. Metod: En kvantitativ tvärsnittsstudie genomfördes på nuklearmedicinska avdelningen där 100 patienter som uppfyllde inklusionskriterierna tillfrågades om medverkan i studien. Efter undersökningen ombads studiedeltagarna att besvara en enkät innehållande nio studiespecifika frågor gällande informationen med fem tillhörande svarsalternativ. Resultat: Studiens resultat visar att 93,4% av studiedeltagarna upplevde den skriftliga informationen som tydlig och lättförståelig. Samtliga enkätfrågor erhöll en median på 4 vilket överensstämmer med svarsalternativet 5 “Instämmer helt”. Resultatet visar att 86 studiedeltagare (94,5%) var nöjda med den muntliga informationen samt att 78 studiedeltagare (88,7%) var nöjda med den skriftliga informationen. Resultatet påvisade att informationen gällande den radioaktiva isotopen erhöll 7 "Instämmer i låg grad" och informationen efter undersökningen erhöll 3 "Instämmer inte alls". Slutsats: Majoriteten av patienter som genomgår en 18F-FDG PET/DT-undersökning är nöjda med informationsinnehållet i samband med undersökningen. Informationen gällande den radioaktiva isotopen samt informationen efter undersökningen behöver dock förbättras. En mer omfattande studie som inkluderar fler studiedeltagare under en längre tidsperiod bör genomföras för ett mer generaliserbart resultat hos den aktuella patientgruppen. / Nuclear Medicine is a speciality in which Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is a common examination. The most common indication for undergoing the examination is known or suspected cancer. Aim: Our aim was to study patients’ experiences regarding the information during an 18F-FDG PET/CT examination. Method: A quantitative cross-sectional study was carried out at the Nuclear Medicine department in which 100 patients who met the inclusion criteria were asked to participate. The participants were asked to answer a questionnaire regarding the information containing of nine study-specific questions with five options. Results: The results of our study showed that 93,4% of the participants perceived the written information as direct and easily comprehensible. All questions received a median score of 4, which corresponds with alternative 5 “Strongly agree”. The result shows that 86 participants (94,5%) were satisfied with the verbal information and that 78 participants (88,7%) were satisfied with the written information. The results showed that the information regarding the radioactive isotope received 7 “Disagree” and the information after the examination received 3 “Strongly disagree”. Conclusion: The majority of patients who undergo an 18F-FDG PET/CT examination are satisfied with the information during the examination. However, the information regarding the radioactive tracer and the information after the examination needs to be improved. A larger study that includes more participants over a longer period of time is suggested to be conducted for more generalized results.

Image guidance and visualization play an important role in modern surgery to help surgeons perform their surgical procedures. Here, the focus is on neurosurgery applications, in particular brain tumor surgery where a craniotomy (opening of the skull) is performed to access directly the brain region to be treated. In this type of surgery, once the skull is opened the brain can change its shape, and this deformation is known as brain shift. Moreover, the boundaries of many types of tumors are difficult to identify by the naked eye from healthy tissue. The main goal of this work was to study and develop image guidance and visualization methods for tumor surgery in order to overcome the problems faced in this type of surgery. Due to brain shift the magnetic resonance dataset acquired before the operation (preoperatively) no longer corresponds to the anatomy of the patient during the operation (intraoperatively). For this reason, in this work methods were studied and developed to compensate for this deformation. To guide the deformation methods, information of the superficial vessel centerlines of the brain was used. A method for accurate (approximately 1 mm) reconstruction of the vessel centerlines using a multiview camera system was developed. It uses geometrical constraints, relaxation labeling, thin plate spline filtering and finally mean shift to find the correct correspondences between the camera images. A complete non-rigid deformation pipeline was initially proposed and evaluated with an animal model. From these experiments it was observed that although the traditional non-rigid registration methods (in our case coherent point drift) were able to produce satisfactory vessel correspondences between preoperative and intraoperative vessels, in some specific areas the results were suboptimal. For this reason a new method was proposed that combined the coherent point drift and thin plate spline semilandmarks. This combination resulted in an accurate (below 1 mm) non-rigid registration method, evaluated with simulated data where artificial deformations were performed. Besides the non-rigid registration methods, a new rigid registration method to obtain the rigid transformation between the magnetic resonance dataset and the neuronavigation coordinate systems was also developed. Once the rigid transformation and the vessel correspondences are known, the thin plate spline can be used to perform the brain shift deformation. To do so, we have used two approaches: a direct and an indirect. With the direct approach, an image is created that represents the deformed data, and with the indirect approach, a new volume is first constructed and only after that can the deformed image be created. A comparison of these two approaches, implemented for the graphics processing units, in terms of performance and image quality, was performed. The indirect method was superior in terms of performance if the sampling along the ray is high, in comparison to the voxel grid, while the direct was superior otherwise. The image quality analysis seemed to indicate that the direct method is superior. Furthermore, visualization studies were performed to understand how different rendering methods and parameters influence the perception of the spatial position of enclosed objects (typical situation of a tumor enclosed in the brain). To test these methods a new single-monitor-mirror stereoscopic display was constructed. Using this display, stereo images simulating a tumor inside the brain were presented to the users with two rendering methods (illustrative rendering and simple alpha blending) and different levels of opacity. For the simple alpha blending method an optimal opacity level was found, while for the illustrative rendering method all the opacity levels used seemed to perform similarly. In conclusion, this work developed and evaluated 3D reconstruction, registration (rigid and non-rigid) and deformation methods with the purpose of minimizing the brain shift problem. Stereoscopic perception of the spatial position of enclosed objects was also studied using different rendering methods and parameter values.

Övergången mellan högskola och arbete kan för många vara en väldigt jobbig period. En bra introduktion för den nyutexaminerade röntgensjuksköterskan är viktigt för att snabbt och enkelt kunna komma in i sitt arbete. Målet med introduktionen är att den nyutexaminerade ska känna en trygghet på arbetsplatsen och bli självständig i sitt arbete. Det finns få studier som belyser ämnet “introduktion på en ny arbetsplats” och ännu färre studier som belyser nyutexaminerade röntgensjuksköterskors åsikter om introduktionen. Förfrågan från ett flertal röntgenavdelningar har lett författarna till ett arbete inom området ”introduktion på arbetsplatsen för nyutexaminerade röntgensjuksköterskor”. Syftet med studien är att undersöka vilka faktorer nyutexaminerade röntgensjuksköterskor upplever är viktiga vid introduktionen på en ny arbetsplats. En kvalitativ studie gjordes med sju kvinnliga informanter i södra och mellersta Sverige. Den insamlade datan analyserades med en innehållsanalys och tre huvudkategorier bildades: Upplevelser av introduktionen; Kommunikation och sociala relationer samt Förbättringsförslag. En viktig faktor som uppskattades av våra informanter är konstruktiv feedback och kontinuitet av handledare för att självsäkerheten ska öka. Mycket av det som tas upp i studien har förbättringspotential för chefer och blivande arbetskollegor. / The transition between university and work can be a difficult period for some people. A good introduction to the new graduated radiographer is important for a quick and easy access to the workplace. The aim of the introduction is to feel safe and independent in the workassignments. Few studies highlight the subject of "introduction on a new workplace” and even fewer studies highlight ”new graduated radiographers’ views on the introduction”. A request from a number of radiology departments has led the authors to write this thesis. The purpose of this study is to examine factors new graduated radiographer considered important for a good introduction on a new workplace. A qualitative study was conducted with seven female informants in southern and central Sweden. The collected data was analyzed with a content analysis and three main categories were formed: Experiences of the introduction; Communication and social relations; Suggestions for improvement. Something that was appreciated by our participants was constructive feedback and continuity of supervisors to increase self-confidence. The content in this study has an improvement potential for managers and future colleagues.

Titel: Röntgensjuksköterskans upplevelse av att arbeta med externa granskare under jourtid Syfte: Att undersöka hur röntgensjuksköterskan upplever arbetet med externa granskare under jourtid. Material och metod: Sex stycken röntgensjuksköterskor från två olika sjukhus i mellansverige intervjuades under perioden januari till mars 2017. Inklusionskriterierna för studien var minst två års erfarenhet av yrket samt minst ett års erfarenhet av att arbeta med externa granskare under jourtid. Tillstånd från verksamhetschefer och samtycke från informanterna erhölls innan studien startade. Data samlades in genom en kvalitativ metod med semistrukturerade intervjuer bestående av öppna frågor. Den insamlade datan analyserades med kvalitativ innehållsanalys enligt Graneheim & Lundman. Intervjuerna transkriberades och lästes igenom flera gånger. Därefter identifierades meningsbärande enheter och dessa kondenserades till koder. Genom koderna kunde kategorier och subkategorier identifieras. Resultat: I resultatet framkom fyra kategorier; Teleradiologi – tekniska aspekter, externa granskare jämfört med radiolog på plats, kommunikation och röntgensjuksköterskans kompetenser och egenskaper med tillhörande subkategorier. Konklusion: Informanterna upplever att det tar längre tid att kommunicera med externa granskare (EG) i jämförelse med att ha en radiolog på plats som kan ge svar direkt när röntgensjuksköterskan (RSS) är i behov av vägledning och snabba svar. I kommunikationen upplevs det också finnas språkbarriärer samt bristande kunskap, speciellt hos de sekreterare som tar emot samtal hos EG. Detta leder till frustration och blir ofta ett hinder i akuta situationer då RSS vill prata med en radiolog direkt. Under jourtid upplever RSS att denne får ta ett ökat ansvar samtidigt som förmågan att ta egna initiativ och beslut måste finnas. RSS upplever ingen förändring av bildkvalitén på de bilder som skickas i arbetet med EG. Informanterna upplevde i helhet att arbetet med EG fungerar bra och tillfredsställande under förutsättningarna att tekniken fungerar som den ska samtidigt som arbetsflödet inte ökar för mycket.

La radiothérapie interne vectorisée (RIV) permet une irradiation systémique la plus élective possible des lésions métastatiques de cancers. Nous rapportons une étude de phase I avec première injection à l’homme mise en place au Centre Léon Bérard pour le traitement de patients porteurs de métastases de synovialosarcomes. Sur un schéma théranostique, une étape d’imagerie et de dosimétrie était réalisée afin d’étudier la biodistribution du radiopharmaceutique diagnostique (RPD) compagnon du radiopharmaceutique thérapeutique (RPT). En cas de biodistribution favorable (fixation tumorale supérieure aux organes sains environnant) permettant d’envisager la RIV avec un effet tumoricide tout en limitant les effets secondaires de l’irradiation de tissus sains, les patients recevaient le RPT. Au total 20 patients ont été inclus. Dix d’entre eux étaient éligibles à la phase thérapeutique : 2 n’ont pas pu être traités du fait d’une progression de la maladie et 8 ont été traités, incluant 1 patiente ayant pu recevoir une 2ème injection de RPT du fait d’une stabilisation de la maladie. Les effets secondaires ont été principalement hématologiques. Les réponses au traitement ont été des stabilisations transitoires. Face à ces résultats modestes, nous avons réalisé une étude dosimétrique plus approfondie pour mieux les comprendre. Nous discuterons des voies possibles pour optimiser ce traitement en s’appuyant notamment sur les études de RIV ayant montré de réels bénéfices pour les patients / Vectorized Radionuclide Therapy allows a more elective systemic irradiation of metastatic cancer lesions. We are reporting a first in human phase I study set up at the Léon Bérard Cancer Centre for the treatment of patients with synovialosarcoma metastases. Following a theranostic scheme, an imaging and dosimetry step was performed to study the biodistribution of the diagnostic radiopharmaceutical (DRP) companion of the therapeutic radiopharmaceutical (TRP). In case of favorable biodistribution (tumor uptake greater that surrounding healthy organs tracer uptake) allowing IVR to be considered with a tumoricidal effect while limiting the side effects of irradiated healthy tissues, patients received the TRP. A total of 20 patients were included. Ten of them were eligible for the therapeutic phase: 2 could not be treated due to disease progression and 8 were treated, including 1 patient who received a 2nd injection after disease stabilization. The side effects were mainly hematological. Treatment responses were transient stabilizations. In response to these modest results, we conducted a more in-depth dosimetric study to better understand them. We will discuss possible ways to optimize this treatment, based in particular on RIV studies that have shown real benefits for patients

Bakgrund: Cone beam computed tomography (CBCT) är en form av datortomografi vanlig inom odontologi och börjar utnyttjas mer inom ortopedisk diagnostik. Frakturer i övre extremiteter är vanligt förekommande i samband med trauma. Konventionell röntgen är oftast förstahandsmetod men kan inte alltid utesluta scaphoideumfraktur, som obehandlad kan ge allvarliga konsekvenser. Syfte: Syftet är att utvärdera CBCT som metod vid fraktur i övre extremiteter genom att jämföra med andra modaliteter. Metod: Arbetet är en systematisk litteraturstudie. Databaserna Medline, CINAHL och PubMed användes. Endast artiklar publicerade inom de senaste 10 åren inkluderades. Kvalitetsgranskning utfördes med protokoll från Hälsohögskolan i Jönköping. Resultat: 15 artiklar inkluderades i resultatet. Faktorer som identifierades var konkordans, stråldos, bildkvalitet, diagnostisk kvalitet samt patienttolerans och undersökningstid. CBCT hade överlägsen eller likvärdig konkordans. I åtta av nio artiklar visades CBCT ha lägre stråldos än jämförande modalitet. Generellt var bildkvaliteten god för CBCT. Skilda resultat uppkom för diagnostisk förmåga. Patienttoleransen var högre för CBCT än multidetektor-CT (MDCT) gällande tid. Slutsats: CBCT påvisade god bildkvalitet och diagnostisk förmåga till en relativt låg stråldos, samt högre sensitivitet och specificitet än konventionell röntgen. På grund av skillnader i mätinstrument i det insamlade materialet kan ingen definitiv slutsats dras. Vidare studier inom ämnet rekommenderas. / Background: Cone beam computed tomography (CBCT) is a method commonly used in odontology and is becoming more used in orthopedic diagnostics. Fractures in upper extremities are a common occurrence in trauma. Conventional radiography is often the firsthand method but cannot always exclude scaphoid fractures, which untreated can have serious consequences. Purpose: The purpose is to evaluate CBCT as an examination method for fractures in the upper extremities by comparing with other modalities. Method: This study is a systematic literature review. The databases used were Medline, CINAHL and PubMed. Only articles published within the last 10 years were included. A quality audit was implemented using a protocol from Jönköping University. Results: 15 articles were included. The factors identified were observer agreement, radiation dose, image quality, diagnostic quality, patient tolerance and image duration. CBCT had a better or equal observer agreement. In eight out of nine articles, CBCT was shown to have a lower radiation dose than its comparative modality. In general, a good image quality in CBCT was found. Differing results were found about diagnostic ability. The patient tolerance was higher for CBCT than multidetector-CT (MDCT) regarding image duration. Conclusions: CBCT demonstrated a good image quality and diagnostic ability to a relatively low radiation dose, and a higher sensitivity and specificity than conventional radiography. Due to differences in measuring instruments used in the gathered material, no definitive conclusion could be drawn. Further studies in the subject is recommended.

O uso de simulação Monte Carlo do transporte de radiação na matéria tem sido cada vez mais empregado nas áreas de física radiológica e dosimétrica. Em Medicina Nuclear é possível usar diversos códigos de simulação como ferramenta para estudar diferentes características de resposta de calibradores de dose. O código de simulação Monte Carlo PENELOPE (Penetration and ENErgy LOss of Positron and Electrons) possui um algoritmo misto do transporte de radiação, condensando eventos de interação, conforme os parâmetros de entrada estabelecidos. Neste trabalho, o código de simulação PENELOPE foi usado para estudar a resposta de uma câmara de ionização em função de diversos parâmetros que influenciam suas características de resposta. Neste trabalho os parâmetros de resposta de uma câmara de ionização tipo poço foram estudados através de simulação Monte Carlo, comparando-se os resultados obtidos com dados experimentais. A eficiência da câmara foi testada através de simulação e mostrou-se condizente com os valores previstos através de cálculos. Com relação à atividade, a resposta se mostrou linear para todos os nuclídeos estudados, sendo possível se obter a sensibilidade relativa da câmara através de simulação e de medidas experimentais. A resposta da câmara em função a energia, obtida através de simulação, também representou bem os valores experimentais, sendo possível extendê-los para energias mais altas e mais baixas que os valores das medidas experimentais. Estudos do volume de radiofármaco e da posição da fonte no poço da câmara obtidos através de simulação apresentaram comportamento esperado de acordo com a literatura. O código PENELOPE foi validado para o estudo desta câmara de ionização, permitindo que parâmetros geométricos e de materiais sejam estudados sem os custos e as dificudades dos arranjos experimentais. / The use of Monte Carlo simulation to the radiation transport in matter has been widly applied in the radiological and dosimetric areas. In Nuclear Medicine it is possible to use a variety of simulation codes as tools to study different response characteristics of dose calibrators used to measure radionuclides activities. The PENELOPE (Penetration and ENErgy LOss of Positron and Electrons) Monte Carlo simulation code has a mixed algorithm for the transport of radiation, which condenses the interaction events according to the input parameters. In this work, the PENELOPE code of simulation was used to study the response of an ionization chamber as function of parameters influencing its response. The chamber efficiency was tested by simulation and it showed a good agreement with calculated results. To the activity, its response showed a linear behavior for all studied nuclides, allowing one to obtain its sensitivity by simulation and measurements. The response of the chamber as a function of the energy obtained by simulation also showed a good agreement with the measurements, allowing one to extrapolate it to energies below and above the measured ones. The analysis with the volume of radiopharmaceuticals and position of the sourse in the chamber well obtained by simulation showed the expected behavior compared to the ones in literature. PENELOPE was validated to study this ionization chamber, so allow one to perform geometric and material parameters studies without experimental costs and difficulties.