Bakgrund: Kunskapen om barnmisshandel hos vårdpersonal har börjat kritiseras i Sverige. Röntgensjuksköterskan är skyldig att rapportera vid misstänkt barnmisshandel och behöver därför kunna identifiera dessa fall. Syfte: Syftet var att beskriva radiologiska fynd som kan indikera barnmisshandel. Metod: Studierna i denna litteraturstudie kvalitetsgranskades, analyserades och bearbetades för att sammanställa ett resultat. Tio kvantitativa studier ingick i resultatet för litteraturstudien. PubMed och CINAHL användes som sökdatabaser. Resultat: Resultatet presenterades i tre kategorier: hjärnskador och blödningar, frakturer och ligamentskador. Konklusion: Vanliga radiologiska fynd som kan indikera barnmisshandel är subduralblödningar, revbensfrakturer och rörbensfrakturer. Vidare forskning bör utföras för att undersöka prevalensen av frakturer i händer och fötter samt ligamentskador i halsryggen vid misstänkt barnmisshandel. / Background: Swedish health care professionals’ knowledge about child abuse has lately been criticized. The radiographer is obligated to report on suspected child abuse and therefore needs to be able to identify these cases. Aim: The aim was to describe radiological findings that might indicate child abuse. Method: The studies in this literature review were quality assessed, analyzed and processed to compile the results. The results consisted of ten quantitative studies. PubMed and CINAHL were used as search databases. Results: The results were presented in three categories: brain injuries and hemorrhages, fractures and ligamentous injuries. Conclusion: Common radiological findings that might indicate child abuse are subdural hemorrhages, rib fractures and long bone fractures. Continued research should be conducted to investigate the prevalence of fractures in hands and feet, and also ligamentous injuries of the cervical spine in suspected child abuse.

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.

Bakgrund: Trots kriminalisering av barnaga är barnmisshandel förekommande, vilket påträffas i alla samhällsklasser och miljöer. Mörkertalet för misshandel av barn är stort vilket kräver rätta kunskaper och förmågor för att efterfölja den lagstadgade anmälningsplikten för vård, skola och omsorg. Syfte: Syftet med studien är att få en djupare förståelse om röntgensjuksköterskans kunskaper för att upptäcka fysisk misshandel av barn under tre år inom Bild- och funktionsmedicinska avdelningar. Metod: En kvalitativ studie baserad på semistrukturerade intervjuer med fyra legitimerade röntgensjuksköterskor, verksamma på två större universitetssjukhus i mellersta Sverige. Erhållet datamaterial analyserades med den induktiva kategoriseringsansatsen. Resultat: I resultatet framkom olikheter i röntgensjuksköterskans förmåga att upptäcka barnmisshandel. Att röntgensjuksköterskan är medveten om anmälningsplikten framkom tydligt, men det individuella ansvaret att upptäcka och agera på en röntgenavdelning varierade. Informanterna kunde notera kliniska kännetecken vilket grundar sig på tidigare erfarenheter utifrån utredningar av fysisk misshandel samt dess yrkesroll att kunna bedöma bildtagningens kvalité baserat på verksamhetens riktlinjer. I det personliga bemötandet mellan barn, föräldrar och vårdnadshavare uppkom brister vilket speglar sig i dess tidigare teoretiska kunskaper från grundutbildning till interna utbildningar. Ingen av deltagarna anmälde själva till socialstyrelsen vid subtila fall utan lämnade över ansvaret till överordnad. Slutsats: Röntgensjuksköterskorna är väl medvetna om plikten att anmäla barnmisshandel men upplever svårigheter att upptäcka barn som far illa, såsom att uppskatta sin individuella betydelse i vårdkedjan. Studien är användbar och kan replikeras för vidare forskningsmöjligheter. / Background: Although, all forms of child abuse are regarded as a crime it still happening today, independently of social class and environmental area. Since the unrecorded number of child abuse is high, it requires qualified and specific abilities in order to uphold the statutory obligation to report. Aim: The aim of this research is within radiology departments to acquire a deeper understanding of the radiographer’s role and knowledge in discovering physical abuse of children under three years old. Method: A qualitative study based on semi structured interviews, done with four qualified radiographers, operating in two large university hospitals in central Sweden. The conventional content analysis approach is used to analyze the documented material. Results: The result is showing differences in the radiographer’s ability in identifying child abuse. The radiographers are aware of their role in reporting any abuse of a child. However, the individual responsibility to understand the signs and then act upon them vary. The participants were able to notice clinical signs, based on their earlier experience. Although, lack of knowledge was shown in terms of interaction between parents, children and care giver, which is reflecting the radiographers earlier theoretical and internal education. Conclusion: The radiographers are aware of their role of reporting child abuse, although seeing difficulties in identifying physical abuse. Challenges were even shown in understanding their role of expertise and importance in the whole health care chain. The study can be replicated and used for further research possibilities.

Deformable image registration (DIR) is an essential tool in medical image processing. It provides a means to combine image datasets, allowing for intra-subject, inter-subject, multi-modality, and multi-instance analysis, as well as motion detection and compensation. One of the most popular DIR algorithms models the displacement vector field (DVF) as B-splines, a sum of piecewise polynomials with coefficients that enable local shape control. B-splines have many advantageous properties in the context of DIR, but they often struggle to adequately model steep local gradients and discontinuities. This dissertation addresses that limitation by proposing the replacement of conventional B-splines with a generalized formulation known as a Non-Uniform Rational B-Splines (NURBS). Beginning with the 1D fitting, heuristic rules are developed to determine the values of the additional free parameters introduced by NURBS. These rules are subsequently modified and extended to the 2D and 3D fitting of anonymized and publicly available patient DVFs. Based on the lessons learned from these increasingly complex test cases, a 2D DIR scheme is developed and tested on slices from a thoracic computed tomography (CT) scan. Finally, an automatic, non-uniform scheme is presented, and its registration performance is compared to the conventional uniform methods.

Introduction Radiologic Technologists exposed to continuous low dose radiation may have an increased risk for spontaneous abortions. Although the federally mandated radiation dose limit to the developing fetus of an occupational worker is 5mSv, well below the documented threshold of 100mSv, some studies have suggested an increased risk for spontaneous abortions in occupationally exposed females. The effects of exposure to low levels of radiation are difficult to discern from the usual occurrence and are limited in the literature because of the large sample size needed to achieve statistical power. This study contains data from 152,439 self-reported pregnancies and possesses the appropriate sample size to assess the risk of spontaneous abortions incident to radiologic technologists who maintain fetal radiation dose levels within federal guidelines. Methods This non-experimental retrospective designed study uses data from the United States Radiologic Technologist Study (USRTS). The USRTS began in 1982 as a joint effort between the American Registry of Radiologic Technologists (ARRT),UniversityofMinnesotaand the National Cancer Institute to study the radiation effects from low-dose occupational exposure. This longitudinal study follows more than 90,000 current and former technologists through periodic surveys and contains a sufficient sample size to overcome statistical power concerns. The provided data included the order and outcome of each self-reported pregnancy as well as the year of each live birth. The data were therefore manipulated to provide a likely gestational interval for both a reported live birth and spontaneous abortion. After calculating the spontaneous abortion rate for the final sample, a binary logistic regression was performed to determine if levels of estimated fetal radiation dose are associated with predicting the odds of a reported spontaneous abortion. A linear regression analysis was then performed to assess the relationship between the calculated odds ratios of a reported spontaneous abortion as a function of estimated fetal radiation dose, specifically to determine the significance of the linear relationship Results The overall spontaneous abortion incidence to the cohort reporting at least one live birth or spontaneous abortion was 14.8%, lower than the reported national incidence of 15-20%. Using up to 1mSv as the reference fetal radiation dose category, the odds ratios of a spontaneous abortion for 1-2mSv, 2-3mSv, 3-4mSv and 4-5mSv were calculated as 1.57, 1.82, 2.11 and 2.15 respectively. This increase in odds was linear with estimated fetal radiation dose as demonstrated by the significant regression equation (F=29.93, p = .01) and an R2 of 0.9089. Conclusions By demonstrating an increased risk at levels of radiation as low as natural background, and further demonstrating the risk increases linearly with radiation dose, the Linear Non-Threshold Theory appears to be the more likely risk model for predicting spontaneous abortions in lieu of the belief that a 100mSv threshold must first be exceeded for a radiation induced spontaneous abortion to occur. Application of this model demonstrates the risk of a spontaneous abortion is twice as likely in occupational workers whose fetal radiation doses are closer to the maximum allowable limit of 5mSv compared with those who maintain fetal radiation doses below 1mSv.

This thesis examines the utility of USPIO-MRI to provide a tool of tracking macrophage recruitment to sites of neuroinflammation within the CNS. Recruited macrophages and microglia resident in CNS tissue play a key role in the pathophysiology of a number of neuroinflammatory diseases such as neuropathic pain and multiple sclerosis. Under activated conditions, microglia and macrophages will phagocytose invading cells and CNS debris. It has been shown that ultrasmall superparamagnetic particles of iron oxide (USPIO), such as Sinerem, injected systemically, are engulfed by macrophages, which in turn migrate to sites of tissue injury. USPIOs can be visualised as a distinct reduction in signal intensity on T2* weighted MR images. However, there are still some issues regarding the distinction between iron-laden recruited macrophages and the entry of free iron across a permeable blood brain barrier (BBB) in disease cases. Hence, it was shown that intravenously injected Sinerem is cleared from the peripheral circulation within 24 hours, indentifying this as a time point as suitable for MCP-1 injection. Data showed that free USPIO can be visualised in the brain and that there is a linear relationship between Sinerem concentration and T2* signal intensity changes. MCP-1 induces macrophage recruitment to the site of microinjection and causes BBB breakdown at between 3 and 4 hours. In particular it was shown that T2* signal intensity changes are seen, in the presence of an intact BBB, as a result of Sinerem laden macrophages. This finding was verified by the co-localisation of ED-1 positive cells and Prussian blue positive regions. It was demonstrated that there is a strong correlation between T2* signal changes and the number of macrophages. This demonstrates that USPIO-MRI can be used to characterise macrophage infiltration in neuroinflammation in the presence of an intact BBB.

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.

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.

The goal of this study was to improve dosimetry for pelvic, lung, head and neck, and other cancers sites with aspherical planning target volumes (PTV) using a new algorithm for collimator optimization for intensity modulated radiation therapy (IMRT) that minimizes the x-jaw gap (CAX) and the area of the jaws (CAA) for each treatment field. A retroactive study on the effects of collimator optimization of 20 patients was performed by comparing metric results for new collimator optimization techniques in Eclipse version 11.0. Keeping all other parameters equal, multiple plans are created using four collimator techniques: CA0, all fields have collimators set to 0°, CAE, using the Eclipse collimator optimization, CAA, minimizing the area of the jaws around the PTV, and CAX, minimizing the x-jaw gap. The minimum area and the minimum x-jaw angles are found by evaluating each field beam’s eye view of the PTV with ImageJ and finding the desired parameters with a custom script. The evaluation of the plans included the monitor units (MU), the maximum dose of the plan, the maximum dose to organs at risk (OAR), the conformity index (CI) and the number of fields that are calculated to split. Compared to the CA0 plans, the monitor units decreased on average by 6% for the CAX method with a p-value of 0.01 from an ANOVA test. The average maximum dose remained within 1.1% difference between all four methods with the lowest given by CAX. The maximum dose to the most at risk organ was best spared by the CAA method, which decreased by 0.62% compared to the CA0. Minimizing the x-jaws significantly reduced the number of split fields from 61 to 37. In every metric tested the CAX optimization produced comparable or superior results compared to the other three techniques. For aspherical PTVs, CAX on average reduced the number of split fields, lowered the maximum dose, minimized the dose to the surrounding OAR, and decreased the monitor units. This is achieved while maintaining the same control of the PTV. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

O desenvolvimento da tecnologia de tomografia computadorizada (TC) trouxe maiores possibilidades em medicina diagnóstica. É um método não invasivo de se explorar o corpo humano detalhadamente. Com o aumento das aplicações em TC, aumenta a preocupação com as altas taxas de dose administradas quando comparada com outras modalidades de diagnóstico por imagem. A comunidade científica e os fabricantes uniram esforços para alcançar níveis menores de dose possíveis, sem comprometer a qualidade da imagem diagnóstica. O maior e relativamente novo avanço nessa busca para diminuir os níveis de dose é o controle automático de exposição (CAE) em TC. Esses sistemas foram projetados para ponderar a distribuição de dose ao longo do comprimento de varredura e entre pacientes, levando em consideração o tamanho e as diferentes densidades de tecidos irradiados. Baseando-se na geometria de aquisição em TC, os sistemas CAE são altamente complexos. Sendo assim, sua forma de funcionamento ainda não é inteiramente conhecida. O presente trabalho tem como objetivo avaliar o desempenho clínico dos sistemas CAE, suas susceptibilidades ao usuário e, com isso, ajudar na otimização de dose em pacientes. A abordagem utilizada para avaliar os sistemas CAE de três dos maiores fabricantes de TC no Brasil, General Electric, Philips e Toshiba, foi pela extração dos valores de corrente anódica do cabeçalho da sequência de imagens no padrão DICOM, medição e análise do ruído das imagens dessas sequências e a medição da distribuição da dose ao longo do comprimento de varredura nas superfícies e dentro de dois simuladores de paciente de formatos diferentes. A variação da corrente anódica de cada equipamento de TC associada à qualidade da imagem resultante fornece o desempenho do sistema CAE. As medições de distribuição de dose fornecem o perfil de dose resultante da modulação de corrente. Medições com e sem o sistema CAE acionado foram feitas para quantificar a importância em termos de dose desses sistemas. Os resultados obtidos permitem otimizações no uso dos sistemas CAE e, consequentemente, a redução da dose no paciente sem comprometer a qualidade diagnóstica da imagem. / The development of the computed tomography (CT) technology has brought wider possibilities on diagnostic medicine. It is a non-invasive method to see the human body in details. As the CT application increases, it raises the concern about patient dose, because the higher dose levels imparted compared to other diagnostic imaging modalities. The radiology community (radiologists, medical physicists and manufacturer) are working together to find the lowest dose level possible, without compromising the diagnostic image quality. The greatest and relatively new advance to lower the patient dose is the automatic exposure control (AEC) systems in CT. These systems are designed to ponder the dose distribution along the patient scanning and between patients taking into account their sizes and irradiated tissue densities. Based on the CT scanning geometry, the AEC-systems are very complex and their functioning is yet not fully understood. This work aims to evaluate the clinical performance of AEC-systems and their susceptibilities to assist on possible patient dose optimizations. The approach to evaluate the AEC-systems of three of the leading CT manufacturers in Brazil, General Electric, Philips and Toshiba, was the extraction of tube current modulation data from the DICOM standard image sequences, measurement and analysis of the image noise of those image sequences and measurement of the dose distribution along the scan length on the surface and inside of two different phantoms configurations. The tube current modulation of each CT scanner associated to the resulted image quality provides the performance of the AEC-system. The dose distribution measurements provide the dose profile due to the tube current modulation. Dose measurements with the AEC-system ON and OFF were made to quantify the impact of these systems regarding patient dose. The results attained give rise to optimizations on the AEC-systems applications and, by consequence, decreases the patient dose without compromising the diagnostic image quality.