Vid folksjukdomar som stroke, cancer och demens kan det kapillära blodflödet (perfusionen) i hjärnan påverkas. Genom att studera blodflödet ökar möjligheten att ställa rätt diagnos och i vissa fall kan även behandlingseffekt bedömas via ändringar i blodflödet Med en metod som kallas "dynamic susceptibility contrast magnetic resonance imaging" (DSC-MRI) kan blodflödet mätas med magnetkameIntroductionThe perfusion-related parameters cerebral blood flow (CBF) and cerebral blood volume (CBV) can be measured using dynamic susceptibility-contrast magnetic resonance imaging (DSC-MRI). However, absolute values of CBF and CBV are often overestimated and quantification of these parameters is challenging. By acquiring an independent absolute CBV estimate, a calibration factor can be obtaine

Purpose: The purpose of this work was to explore the possibility to compare treatment-planning- and treatment-delivery systems for intensity modulated radiation therapy (IMRT) using an objective approach. The approach investigated was the Pareto front concept. An additional aim was to adequately compare three different IMRT treatment planning and delivery systemsMaterials and methods: In IMRT trea

ntensity modulated radiation therapy (IMRT) is becoming a more and moreused technique in radiation therapy. The main reason for this is that IMRT treament delivers a more conformal dose to the target together with a better sparing of organs at risk. Quality assurance of the generated IMRT treatment plan is of most importance to ensure that the patient recives the planned dose. Different methods ex

Introduction: SharePlanTM is a new type of treatment planning system produced by RaySearch Laboratories AB for TomoTherapy Inc. SharePlan enables transfer of treatment plans generated with the TomoTherapy Hi∙Art® system to plans deliverable at conventional linacs. The main reason for this is to ensure continuous patient treatment if the TomoTherapy unit “goes down”, e.g. at clinics with only one T

Introduction: Regional and global brain volumes are of great interest in many different research projects, not least in Alzheimer’s research. The purpose of this project is to optimize the MPRAGE sequence for automatic and repeatable segmentation of human brain tissue. The volume is calculated for the whole brain, white matter (WM), grey matter (GM) and cerebrospinal fluid (CSF). Materials and met

Introduction; The aim of this study was to examine the possibilities for MRI-based radiotherapy treatment planning. The work included evaluation of geometric image distortions in MR-images, investigations of how segmentation of bone could be performed from images acquired with the ultra short time of echo (UTE) pulse sequence and assessment of dosimetric differences between treatment planning base

Purpose: Radiotherapy of moving tumours is a great challenge in cancer treatment. The moving target will lead to “dose-smearing” of the planned dose distribution and a need for larger margins. To reduce the dose to the surrounding healthy tissue, while still ensuring full coverage of the target, other methods for motion compensation is needed. Inversely optimised arc radiotherapy, where the treatm

Jag har i detta arbete tagit fram en metod för att mäta mängden fett i muskelceller som vare sig kräver vävnadsprover eller nålstick. Metoden ger också en bild av fettfördelningen i vävnaden. Detta kan vara mycket användbart vid utveckling av läkemedel, men också vid diabetes- och fetmaforskning. Muskelceller innehåller ett bränsleförråd i form av en droppe fett. För diabetespatienter och som en b"Introduction Cardiac steatosis, or overstorage of fat in the cardiac muscle cells, is a possible side effect from drugs treating diabetes mellitus. Therefore, a non-invasive means of fat quantification is needed during drug development. The aim of this master thesis is to develop a method to quantify the fraction intra-myocellular fat in the cardiac muscle of rats using magnetic resonance im

En ofta använd behandlingsmetod mot cancer är strålbehandling. Inför en sådan behandling undersöks patienten ofta med en typ av röntgenundersökning som kallas datortomografi (eng. computed tomomgraphy, CT). Röntgenbilderna visar hur mycket av strålningen som absorberas av kroppen, vilket innebär att man tydligt ser skillnad mellan ben, som absorberar mer av strålningen än vävnad och luft, som strå"Introduction; The aim of this study was to examine the possibilities for MRI-based radiotherapy treatment planning. The work included evaluation of geometric image distortions in MR-images, investigations of how segmentation of bone could be performed from images acquired with the ultra short time of echo (UTE) pulse sequence and assessment of dosimetric differences between treatment plannin

Monte Carlo-simuleringar har fått en ökad betydelse som forskningsverktyg inom nuklearmedicinsk bildgivning eftersom man på ett mycket kontrollerat sätt kan studera nästan vad man vill. I denna studie har datorsimuleringar av ett PET-system gjorts med ett program som heter GATE. PET (Positron Emission Tomography) är en nuklearmedicinsk bildgivningsteknik som används mer och mer inom sjukvården sIntroduction: Monte Carlo simulation is a powerful tool in research in the field of nuclear medicine imaging and there is a wide area of applications. The purpose of this work was (1) to understand the basics of the Monte Carlo simulation software Geant4 Application for Tomographic Emission (GATE); (2) to create a model of Philips Gemini TF PET/CT system; (3) to run a number of simulations to comp

En vanlig typ av behandling vid cancer är strålbehandling. Tekniken har utvecklats mycket de senaste åren och med ny teknik kommer bättre behandlingsresultat och bättre skydd mot strålningen. När det är dags att byta ut en äldre behandlingsteknik mot en nyare är det en del faktorer som måste undersökas. Detta arbete undersöker just de möjligheterna vid en ny typ av behandling för läppcancer. StrIntroduction: From 1988 – 2004, patients with squamous cell carcinoma in the lower lip were treated with medium dose rate (MDR) 192Ir wires using a manual afterloading tech-nique. An average of 3 wires were used, each with a mean length of 36 mm (range 27 – 65 mm) and a mean dose rate of 4.5 Gy/h (range 1.8 – 8.7 Gy/h). The average prescribed dose was 21.5 Gy (range 21.0 – 32.6 Gy) at the 85% isod

Idag finns det många olika sätt att avbilda människokroppens inre. Två av de vanligaste metoderna som används idag är magnetresonans (MR) och datortomografi (CT). MR använder sig av starka magnetfält och radiovågor för att skapa snittbilder av kroppen, medan CT använder sig av röntgenstrålar. Båda kamerorna har sina fördelar och nackdelar. MR ger bättre vävnadskontrast, det vill säga det är lättarIntroduction MRI provides better soft tissue contrast than CT and is an invaluable tool in the radiotherapy treatment process. The gold standard today is image fusion of MRI and CT data where targets and organs-at-risk are delineated on the MRI data and the dose calculation is performed on the CT data. It is appealing to exclude CT from the process in order to reduce cost and time and to eliminate

Uppsatsen undersöker hur Jan Myrdal arbetar med satiren som metod i romanen Jubelvår, med utgångspunkt i dess förhållande till den groteska realismen och några av de klassiska 1700-talssatirerna.

Many European countries have recently decided to increase their statutory retirement ages because the demographic change poses a challenge to the stability of social security systems. The success of this policy depends among others on the health effect of such a delayed retirement. This study analyzes the effect of retirement on mental and physical health and further examines whether the health ef

This paper is a study of the meaning and definition behind aesthetic value in contemporary popular music. The material that this paper focuses on consists namely of written essays, published in the daily press, and that are in some way related to the topic, and different takes and views regarding value. These essays will help serve as the base of the discussion in this paper, and to help explain a

Titel: Den nya Försvarsmakten: En studie om en myndighets förändrade kommunikation. Problem: Den offentliga sektorn har under senaste decenniet ställts inför en allt större marknadsorientering och ett snabbt förändrande samhälle. Dessa förändringar skapar nya utmaningar och behov för det strategiska kommunikationsarbetet. Det är därför intressant att studera hur en myndighet som Försvarsmakten beTitle: The Swedish Armed Forces: a study on the changing communication of a public authority. Problem: In recent decades the public sector has been faced with an increasing market orientation and a rapidly changing society. These changes can be assumed to create new demands as well as major changes to the work of strategic communications. Thus, it is interesting to study how an authority, as The

A report produced by the Swedish Building Commission, pointed out that high costs and poor quality exists in the construction industry. With the goal of getting a more effective building process NCC Construction AB implemented a new production control system. NCC calls the system NCC Project Planning (Swedish: NCC Projektplanering) and it is based on the Last Planner System, a system for planning

The purpose of the paper is to draw attention to the technological advance and its impact on marketing strategies in the hospitality industry. It examines the development of the profile of future consumers and their relationship towards technology. In order to approach the new consumer a brand touch-point wheel framework was used as a filter which enabled to analyze the communication between hotel

Arbetet handlar om att ta fram ett stadsplaneringsförslag i H+ projektet, vilket är ett stadsförnyelseprojekt av södra Helsingborg. Projektets totala yta är ca 100 Ha eller jämförelsevis 140 fotbollsplaner. Stora delar av södra Helsingborg står inför stora förändringar när det gäller både infrastruktur och bebyggelse. Eftersom projektet är så omfattande har det delas in i fem delområden. Arbetets

This thesis is about traditional and modern architecture in Casablanca, Morocco. Morocco is located in north-western Africa and Casablanca is the country's largest city with a population of 3.3 million (2011). Morocco has a long history with many different rulers which have left its mark on the country's architecture. The old, traditional architecture of Casablanca is in the old medina, Me