The liver is one of the largest organs within the human body and it handles many vital tasks such as nutrient processing, toxin removal, and synthesis of important proteins. The number of people suffering from chronic liver disease is on the rise, likely due to the present ‘western’ lifestyle. As disease develops in the liver there are pathophysiological manifestations within the liver parenchyma that are both common and important to monitor. These manifestations include inflammation, fatty infiltration (steatosis), excessive scar tissue formation (fibrosis and cirrhosis), and iron loading. Importantly, as the disease progresses there is concurrent loss of liver function. Furthermore, postoperative liver function insufficiency is an important concern when planning surgical treatment of the liver, because it is associated with both morbidity and mortality. Liver function can also be hampered due to drug-induced injuries, an important aspect to consider in drug-development. Currently, an invasive liver needle biopsy is required to determine the aetiology and to stage or grade the pathophysiological manifestations. There are important limitations with the biopsy, which include, risk of serious complications, mortality, morbidity, inter- and intra-observer variability, sampling error, and sampling variability. Cleary, it would be beneficial to be able investigate the pathophysiological manifestations accurately, non-invasively, and on regional level. Current available laboratory liver function blood panels are typically insufficient and often only indicate damage at a late stage. Thus, it would be beneficial to have access to biomarkers that are both sensitive and responds to early changes in liver function in both clinical settings and for the pharmaceutical industry and regulatory agencies. The main aim of this thesis was to develop and evaluate methods that can be used for a ‘non-invasive liver biopsy’ using magnetic resonance (MR). We also aimed to develop sensitive methods for measure liver function based on gadoxetate-enhanced MR imaging (MRI). The presented work is primarily based on a prospective study on c. 100 patients suffering from chronic liver disease of varying aetiologies recruited due to elevated liver enzyme levels, without clear signs of decompensated cirrhosis. Our results show that the commonly used liver fat cut-off for diagnosing steatosis should be lowered from 5% to 3% when using MR proton-density fat fraction (PDFF). We also show that MR elastography (MRE) is superior in staging fibrosis. Finally we presented a framework for quantifying liver function based on gadoxetate-enhanced MRI. The method is based on clinical images and a clinical approved contrast agent (gadoxetate). The framework consists of; state-of the-art image reconstruction and correction methods, a mathematical model, and a precise model parametrization method. The model was developed and validated on healthy subjects. Thereafter the model was found applicable on the chronic liver disease cohort as well as validated using gadoxetate levels in biopsy samples and blood samples. The liver function parameters correlated with clinical markers for liver function and liver fibrosis (used as a surrogate marker for liver function). In summary, it should be possible to perform a non-invasive liver biopsy using: MRI-PDFF for liver fat and iron loading, MRE for liver fibrosis and possibly also inflammation, and measure liver function using the presented framework for analysing gadoxetate-enhanced MRI. With the exception of an MREtransducer no additional hardware is required on the MR scanner. The liver function method is likely to be useful both in a clinical setting and in pharmaceutical trials.

Inledning: Undersökningar som inkluderar kontrastmedel har ökat på datortomografin (DT). Inför kontrastmedelsundersökningar ska den glomerulära filtrationshastigheten (GFR) estimeras för att få ett mått på patientens njurfunktion. I nuläget finns det två olika markörer som kan användas till detta, kreatinin och cystatin C. Det är röntgensjuksköterskans ansvar att skatta GFR för att kunna göra en bedömning om patienten kan utföra undersökningen. Syfte: Syftet med studien var att sammanställa studier som jämför kreatinin och cystatin C vid skattning av GFR. Metod: Den här studien genomfördes som en allmän litteraturöversikt. Litteratursökningen genomfördes i databaserna CINAHL, PubMed och SveMed+. Tio kvantitativa vetenskapliga artiklar lokaliserades och gick vidare till analys. Resultat: Resultatet visade att cystatin C i många fall var en bättre indikator för att estimera GFR. Slutsats: För äldre och njursjuka ansågs cystatin C vara en bättre markör för njurfunktionen. Dock anser författarna att det krävs vidare forskning inom ämnet och dess påverkande faktorer för att kunna introducera cystatin C som ny njurfunktionsmarkör.

Alzheimer’s disease (AD) is the leading cause of dementia and is alone responsible for 60-70% of all cases of dementia. Though sharing clinical symptoms with other types of dementia, the hallmarks of AD are the abundance of extracellular depositions of β-amyloid (Aβ) plaques, intracellular neurofibrillary tangles of hyper phosphorylated tau proteins and synaptic depletion. The onset of the physiological hallmarks may precede clinical symptoms with a decade or more, and once clinical symptoms occur it may be difficult to separate AD from other types of dementia based on clinical symptoms alone. Since the introduction of radiolabeled Aβ tracer substances for positron emission tomography (PET) imaging it is possible to image the Aβ depositions in-vivo, strengthening the confidence in the diagnosis. Because the accumulation of Aβ may occur years before the first clinical symptoms are shown and even reach a plateau, Aβ PET imaging may not be feasible for disease progress monitoring. However, a negative scan may be used to rule out AD as the underlying cause to the clinical symptoms. It may also be used as a predictor to evaluate the risk of developing AD in patients with mild cognitive impairment (MCI) as well as monitoring potential effects of anti-amyloid drugs.Though currently validated for dichotomous visual assessment only, there is evidence to suggest that quantification of Aβ PET images may reduce inter-reader variability and aid in the monitoring of treatment effects from anti-amyloid drugs.The aim of this thesis was to refine existing methods and develop new ones for processing, quantification and visualization of Aβ PET images to aid in the diagnosis and monitoring of potential treatment of AD in clinical routine. Specifically, the focus for this thesis has been to find a way to fully automatically quantify and visualize a patient’s Aβ PET image in such way that it is presented in a uniform way and show how it relates to what is considered normal. To achieve the aim of the thesis registration algorithms, providing the means to register a patient’s Aβ PET image to a common stereotactic space avoiding the bias of different uptake patterns for Aβ- and Aβ+ images, a suitable region atlas and a 3-dimensional stereotactic surface projections (3D SSP) method, capable of projecting cortical activity onto the surface of a 3D model of the brain without sampling white matter, were developed and evaluated.The material for development and testing comprised 724 individual amyloid PET brain images from six distinct cohorts, ranging from healthy volunteers to definite AD. The new methods could be implemented in a fully automated workflow and were found to be highly accurate, when tested by comparisons to Standards of Truth, such as defining regional uptake from PET images co-registered to magnetic resonance images, post-mortem histopathology and the visual consensus diagnosis of imaging experts.

No description available.

Cerebral small vessel disease (SVD) is identifiable by clinical, neuroimaging, neuropathological and cognitive findings. The aim of this thesis was to assess SVD and cerebral perfusion on magnetic resonance imaging (MRI) in a 75-year-old population and compare the findings with scars of myocardial infarctions, cardiovascular risk markers and cognitive function. In addition, the evolution of SVD over 5 years was studied. The study population included subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. The subjects had been chosen in a randomized manner from the register of the municipality. MRI of the brain and the heart, cognitive tests and blood tests for cardiovascular risk factors were performed in 406 subjects at age 75 years and 250 of them were re-examined 5 years later at the age of 80. Paper 1 showed that unrecognized myocardial infarctions (UMIs) were found in 120 subjects (30%) and recognized myocardial infarctions (RMIs) in 21 (5%). Men with RMIs displayed an increased prevalence of cortical and lacunar cerebral infarctions, whereas women with UMIs more frequently had cortical cerebral infarctions. Paper 2 showed that one or more brain infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts and 2% had both). Hypertension and obesity were significantly associated with an increased risk of infarction.  The newer risk markers investigated were not significantly associated with brain infarcts. Paper 3 showed that MRI manifestations of SVD progressed over 5 years. Relative cerebral blood flow (rCBF) was not associated with WMH volume or progression of WMH volume. Paper 4 showed that moderate to severe WMHs and incident lacunar infarcts on brain MRI were associated with a mild impairment of executive function. In conclusion, this longitudinal population based study compares MRI manifestations of SVD with clinical data, providing knowledge that may be used in further investigations of preventive interventions and for identification of disease in early stages.

Computed tomography urography (CTU) is today the imaging method used to investigate patients with suspected urinary tract malignancy, replacing the old imaging method intravenous pyelography (IVP) about a decade ago. The downside of this shift was that the effective radiation dose to the examined patient was eight times higher for CTU compared to IVP. Based on four different studies, the present thesis focused on efforts to reduce the CTU radiation dose.   In study I, the number of cysts and solid lesions in the separate scan phases was evaluated in 57 patients undergoing four-phase CTU 1997-98. The number of scans was reduced from four to three when the nephrographic scan was abolished following study I. Study II registered the diameter of renal cell carcinoma (RCC) and the presenting symptoms in the total number of patients (n=232) diagnosed with RCC between 1997 and 2003. The results from study II showed that the critical size for RCCs to cause macroscopic hematuria was ≥ 4 cm. Study III was a dose-escalation study aimed to decide the minimal possible tube load in the unenhanced and excretory phase scans if the low dose images are reviewed together with normal dose corticomedullary phase images. Study III showed that it is possible to reduce the mean effective dose in three phase CTU from 16.2 mSv to 9.4 mSv with a combined low and normal dose CTU protocol. Study IV investigated the changes in the CTU protocol between 1997 and 2008, and the development of the effective radiation dose. Study IV clarified how the CTU protocol has changed between 1997 and 2008 and as a result the mean effective radiation dose to patients undergoing CTU in 2008 is only 39% of the effective dose in 1997.   In conclusion, the findings from the studies included in this thesis have contributed to a reduced radiation dose to patients undergoing CTU. The mean effective dose from CTU is at present only three times higher compared to that from the IVP.

Bakgrund: Vissa av röntgensjuksköterskans arbetsuppgifter kan utföras av andra professioner som sjuksköterska eller undersköterska detta kallas för jobbglidning mellan yrkesroller. Jobbglidning kan ske på grund av många olika orsaker som brist på personal, ökad befolkning vilket gör att mer personal behövs inom vården. Att undersköterska eller sjuksköterska utför vissa av röntgensjuksköterskans arbetsuppgifter kan påverka patientsäkerheten. Syfte: Att undersöka röntgensjuksköterskors syn på att arbetsuppgifter inom professionen utförs av sjuksköterska eller undersköterska. Metod: En kvantitativ enkätstudie med 53 deltagare som är legitimerade röntgensjuksköterskor från fyra sjukhus i två olika regioner. Resultat: Majoriteten av deltagarna anser att det är negativt att sjuksköterskor utför arbetsuppgifter inom mammografi och angiografi. Medan flera av deltagarna tycker det är bra om sjuksköterskor kan beräkna GFR inför undersökningar. Deltagarna anser att det är dåligt om undersköterskor utför konventionella röntgenundersökningar och att ge information om kontrastmedel till patienten medan de anser att det var mycket bra om undersköterskor tar in patienter på undersökningsrummet. Slutsats: Studien visar att röntgensjuksköterskorna generellt har negativ syn på att lämna deras arbetsuppgifter till de andra professionerna, utan de vill behålla deras kompetens inom områden som angiografi, mammografi och konventionell röntgen.

Bakgrund: Kontrastmedel används inom medicinsk avbildning för att tolka anatomi och patologi. Gadolinium är den vanligaste typen av kontrastmedel som används inom magnetresonanstomografi (MRT). Eftersom gadolinium är ett läkemedel kan det orsaka biverkningar. Studier har visat att det finns ett samband mellan insjuknandet av nefrogen systemisk fibros (NSF) och gadoliniumkontrastmedel hos njursjuka patienter. Syfte: Att ta reda på vilka biverkningar som kan uppstå efter en gadoliniumkontrastmedelsinjektion och redogöra för hur vanligt förekommande de är. Utöver detta undersöka om patienter med nedsatt njurfunktion insjuknar i NSF av gadoliniumkontrastmedel. Metod: Studien genomfördes som en systematisk litteraturstudie. Resultat: Omtalade biverkningar är skelettsmärta, huvudvärk, illamående, kräkningar och hudförändringar. Ångest, oro, influensaliknande symptom, klåda, osammanhängande tankegång, metallsmak i munnen, ledstelhet och muskelspasm är mindre omtalade biverkningar. Svåra biverkningar förekommer såsom struphuvudsödem, anafylaktisk chock, andningssvårigheter, dyspné och medvetslöshet. Milda biverkningar är mest förekommande. Fyra fall av NSF konstateras i en studie med 261 njursjuka deltagare. I en annan studie med 571 dialyspatienter bekräftades inga fall av NSF. Slutsats: Förekomsten för en biverkning är sällsynt men både omtalade och mindre omtalade biverkningar kan inträffa. Det finns studier som visar ett tydligt samband mellan NSF och gadolinium hos patienter med nedsatt njurfunktion medan andra studier inte kan bekräfta det. Gadoliniumkontrastmedel är relativt riskfritt men observation av patienten bör alltid förekomma. / Background: Contrast media are used in medical imaging to picture anatomy and pathology. Gadolinium is the most common type of contrast media used in magnetic resonance imaging (MRI). The use of gadolinium may cause adverse effects. The association between gadolinium-based contrast media and nephrogenic systemic fibrosis (NSF) in patients with renal insufficiency has been described in earlier studies. Purpose: To describe the most frequent adverse effects caused by gadolinium-based contrast media and their incidence. The study also aims to explain the association between NSF and gadolinium in patients with renal insufficiency. Method: The study has been conducted as a systematic literature review. Results: The well-known adverse effects are bone pain, headache, nausea, vomiting, and skin lesions. Anxiety, flu-like symptoms, pruritus, clouded mentation, metallic taste in the mouth, joint stiffness and muscle spasm are less mentioned. Severe adverse effects also exist such as laryngeal-edema, anaphylactic shock, breathing difficulty, dyspnea and unconsciousness. Mild adverse effects are most common. Four cases of NSF were found in a study with 261 participants with renal disease. In another study 571 patients with dialysis treatment were included, no cases of NSF were confirmed. Conclusion: Both well-known adverse effects and less mentioned adverse effects exist but the occurrence of an adverse effect is rare. There are studies showing a clear association between NSF and gadolinium in patients with renal insufficiency, whilst others can´t confirm it. Gadolinium-based contrast media is relatively risk-free but observation of the patient should always occur.

Bakgrund: Inom röntgensjuksköterskans profession ligger stor vikt på att undersökningarna är så effektiva som möjligt för att hinna med avdelningarnas patientflöden. I dessa sammanhang hamnar patienten lätt i skymundan. Person- och patientcentrerad vård har blivit mer aktuella under de senaste åren, där personcentrerad vård är en del av professionens målbild, vilket lett till ett behov av ökad medvetenhet om begreppen och deras skillnader. Syfte: Studiens syfte var att ta reda på om röntgensjuksköterskor är medvetna om de jobbar med person- eller patientcentrerad vård samt om de vet skillnaden mellan dessa två begrepp och om detta följs upp antingen via utbildningar, föreläsningar eller på arbetsplatsträffar. Metod: En kvalitativ intervjustudie utfördes semistrukturerat med öppna frågor. Intervjuerna utfördes med 15 röntgensjuksköterskor vid två sjukhus. Intervjuerna analyserades med en induktiv manifest innehållsanalys och delades upp utefter domäner, subteman och teman. Resultat: Majoriteten av informanterna på sjukhusen hade någon kunskap angående begreppet patientcentrerad vård från sin utbildning eller arbetsplats. Några få informanter hade hört talas om begreppet personcentrerad vård men för flertalet var detta ett nytt begrepp. Begreppen förväxlades ofta och informanterna kände inte till någon tydlig skillnad. Informanterna kände flera gånger en avsaknad av informering om begreppen från sina avdelningar. Slutsats: Röntgensjuksköterskornas avsaknad av kännedom om begreppet personcentrerad vård visar att det är lång väg kvar innan professionens mål om personcentrerad vård är uppnått på röntgenavdelningar. Genom vidare informering kan medvetenheten om begreppen öka. Tidsbrist var det största hindret för röntgensjuksköterskorna att kunna arbeta utifrån patientens behov. / Background: Within the radiographers' profession, efficiency of examinations is of great importance to keep up with patient flows. In these contexts, patients can easily be forgotten. Person- and patient-centered care have become more relevant in recent years, with person-centeredness being a part of the profession's goals, which leads to a need for increased awareness of the concepts and their differences. Purpose: The study's purpose was to find if radiographers are aware of whether they work person- or patient-centered, whether they know the difference between these two concepts and whether this is followed up either through education, lectures or workplace meetings. Method: A qualitative semi-structured interview study was conducted with open questions. Interviews were conducted with 15 radiographers at two hospitals. The interviews were analyzed with inductive manifest content analysis with regards to domains, sub-themes and themes. Results: Most informants had some knowledge regarding the concept of patient-centeredness from their education or workplace. A few informants had heard of the concept of personcenteredness but for many it was a new concept. The informants did not know any clear difference between the two concepts and often lacked information regarding the concepts from their departments.  Conclusion: The radiographers' lack of knowledge regarding the concept of person-centeredness shows that the profession's goal of person-centered care is far from being achieved in practice. Through further information the consciousness of the concepts can increase. Lack of time was the biggest obstacle for the radiographers to be able to work with patients' need in mind.

<p>Inom hälso- och sjukvården spelar informationsteknologi en allt större roll för utvecklingen. Informationsteknologin har skapat nya förutsättningar där chansen till förbättrade vårdrutiner finns inom många områden genom att införa och utveckla användandet av telemedicin.</p><p>Då vi tror att den telemedicinska potentialen kommer att användas i större utsträckning i framtiden känner vi att det finns ett intresse för en utredning av redan existerande samarbeten inom telemedicin. Vi skrev denna uppsats med syftet att undersöka, identifiera och analysera vad som krävs för att möjliggöra ett effektivt telemedicinskt partnerskap inom sjukvården för att förbättra patientens vård, behandling och ta tillvara på de arbetsprocesser som skapas i och med ett telemedicinskt samarbete. Vi har analyserat två olika typer av telemedicinska samarbeten. Vi har genom en kvalitativ undersökning, främst genom intervjuer, grundligt undersökt två av de bestående nätverken för att sedan analysera dessa med hjälp av den modell vi har sammanställt från de teorier om nätverk som vi utgått ifrån.</p><p>Utifrån analysen om Konsensusnätverket är slutsatsen att samarbetet har lett till en förbättring av kvaliteten i behandlingarna. Utifrån detta kan det konstateras att nätverkets existens inte leder till en direkt effektivisering ur ett tidsmässigt perspektiv. Nätverket leder istället till ett optimalt patientomhändertagande som ur ett långsiktigt perspektiv leder till färre felbehandlingar och därmed indirekta kostnadsbesparingar. Slutsatsen vi dragit från Australiensamarbetena är att det främsta utbytet som ges till de medverkande parterna är en förbättrad kvalitet i arbetsförhållandena och därmed även röntgendiagnoserna.</p>