Medicinsk strålningsvetenskap

Uptake and retainment of radionuclides in edible mushrooms – from fruiting to cooking

Mansour Ayoubi, Delshad (2022-12-06)

Purpose: The purpose of this study was to study the uptake, distribution and transfer of Mn-54, Zn-65, U-238, U-235, U-234, and Po-210 in mushrooms and their respective caps and stalks, the effects of chelates and ligands, ...

CHARACTERIZATION AND EVALUATION OF A NIPAM POLYMER GEL MRI DOSIMETER SYSTEM

Waldenberg, Christian (2022-11-08)

Purpose: The normoxic polymer gel dosimeter based on N-isopropyl acrylamide (NiPAM) is a promising full 3D-dosimeter with high spatial resolution and near tissue equivalency. However, limited work have been done in vestigating ...

Models for estimating radiation dose and LAR from radioactive fallout: extended dose algorithms for the computational tool LARCalc

Sundström, Jonathan (2022-09-09)

Today, emergency preparedness is needed against both nuclear reactor accidents and nuclear weapons fallout. Both scenarios can lead to exposure of ionizing radiation. Upon exposure, radionuclides will incur a radiation ...

Accumulation of 63Ni, 106Ru and 125Sb in phytoplankton

Ali, Yusuf (2022-08-22)

Background: Nuclear Power Plants (NPPs) release small amounts of radionuclides which contribute with a low radiation dose to the environment as well as humans and animals. In this context, marine ecosystems are critical, ...

Evaluation of the DXA radiation environment at Sahlgrenska University Hospital

Söderholm, Saga (2022-05-18)

Purpose: The aims of this work were to evaluate the radiation environment in the dual-energy X-ray absorptiometry (DXA) rooms at Sahlgrenska University Hospital, estimate personnel doses, determine legal requirements for ...

Evaluation of deep learning image reconstruction for brain- and abdominal CT - A visual grading characteristics study

Skarp, Tuva (2022-05-04)

Computed tomography (CT) is a common medical imaging method today. There are different ways of reconstructing the images from a CT examination. The standard method is the filtered back projection (FBP). However, a disadvantage ...

Optimization of MP2RAGE sequence parameters for head and neck T1-mapping and OE-MRI

Börjesson, Ellen (2022-05-04)

Cancer is the collective name for more than 200 types of diseases that annually causes the death of 8.8 million people, cancer in the head and neck (H&N) accounts for 330.000 of these. It has been shown that hypoxic tumors ...

Region-based analysis of magnetic resonance brain images: integrating statistical analysis and visualization

Hsu, Yu-Ping (2022-04-05)

Purpose: The purpose of the project was to develop a processing toolchain that takes MR brain images and their anatomical segmentations as input and produces image visualizations, data visualizations, and statistical ...

Deep Neural Networks for Noise Reduction and Bias Removal in MR Diffusion Signal

Berisha, Beqir (2022-03-22)

The purpose of this study is to assess the potential of deep neural networks, trained by unsupervised learning, for diffusion weighted imaging (DWI) data modeling and denoising. DWI data were modeled by a biexponential ...

Evaluation of the iterative kilovoltage cone-beam computed tomography reconstruction method for the Varian TrueBeam system

Haidari, Tamana (2022-03-18)

Introduction: Radiotherapy is used to treat patients with various types of cancer, where linear accelerators produce the radiation beam used for the treatment. Before each treatment fraction, the patient needs to be ...

Effects of reconstruction parameters on the image quality and quantification of PET images from PET/MRI and PET/CT systems

Hussain, Amena, Ali (2022-03-09)

Aim: To study how reconstruction parameters affect the positron emission tomography (PET) image quality and quantitative results for the different lesion to background radioactivity ratios in three different PET ...

ATLAS-BASED SEGMENTATION OF ULTRAHIGH-RESOLUTION STRUCTURAL MR HEAD IMAGES ACQUIRED AT 7 TESLA

Johansson, Frida (2022-01-13)

Purpose: The purpose of this work was to find out how the existing brain atlases and segmentation algorithms perform when applied to ultrahigh-resolution MR brain images, acquired with a 7-Tesla scanner. Also to make ...

ESTIMATION OF RADIATION EXPOSURE FROM NATURALLY OCCURRING RADIONUCLIDES IN FOOD AND FOODSTUFF

Bengtsson, Ida (2022-01-13)

Purpose: The main purpose of this study was to provide an estimation of the committed effective dose received by the Swedish population from naturally occurring radionuclides (NORM) in the diet. This study was also ...

Establishment of a deep learning algorithm for dosimetry of radiopharmaceuticals

Lipnicevic, Dennis (2022-01-13)

Purpose: The aim of this study was to introduce a volumetric convolutional neural network for segmentation of the kidneys in SPECT images and to apply it in the dosimetry of radiopharmaceuticals of this organ, in order ...

STANDARDIZED ORGAN AT RISK VOLUME FOR EXTERNAL BEAM RADIATION THERAPY IN PROSTATE CANCER AND ITS RELATIONSHIP TO VOLUMES DEFINED BY CLINICAL PRACTICE

Thao, Dang (2022-01-13)

Background/ Purpose: In radiation therapy (RT), the radiation dose calculated in tumours and normal tissue depends on how the volumes are defined. It is difficult to standardize how tumour volumes should be defined ...

osimetric impact of system spe cific geometric distortion on head and neck treatment plans in MRI only based radiation therapy

Brovall, Jesper (2022-01-13)

Background/ purpose: Because of the superior soft tissue contrast, in comparison with computed tomography (CT) data, magnetic resonance imaging (MRI) is of high interest to include in a larger extent in the ra diation ...