Medicinsk strålningsvetenskap
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Evaluation of the DXA radiation environment at Sahlgrenska University Hospital
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
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
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
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
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
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
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
(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
(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
(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
(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
(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 ... -
Evaluation of whole-body bone scans performed using a gamma camera with Cadmium Zinc Telluride detector
(2022-01-13)The bone scan is a common nuclear medicine imaging procedure that is mainly used for evaluating several oncological patient groups. A radioactive tracer, 99mTc -labelled diphosphonate, is injected intravenously and ... -
Measuring natural hemispheric asymmetry in the brain: quantifying the Yakovlevian torque phenomenon
(2022-01-13)Background: Just by a cursory examination, the two hemispheres of the human brain may appear as mirror images of one another. Yet, the left and right sides exhibit profound differences in anatomy. One of the most obvious ... -
COMPARISON OF MULTI-CRITERIA OPTIMIZATION IN TWO DIFFERENT TREATMENT PLANNING SYSTEMS
(2021-05-10)Purpose: The purpose with this study was to compare multi-criteria optimization (MCO) for volumetric modulated arc therapy (VMAT) treatment plans in two different treatment planning systems. Theory: When performing ... -
Characterization of discrepancies between manual and automatic segmentation to improve anatomical brain atlases
(2021-05-10)Purpose: To characterize discrepancies between expert manually segmented brain images from Hammers Atlas Database and automatically generated segmentations of the same images; to decide whether they can be attributed ... -
FETAL DOSE ESTIMATION IN ABDOMINAL AND PELVIC CT EXAMINATIONS
(2021-05-10)Purpose: The purpose of this is study was to compare different methods for estimating the fetal dose, how much the different methods differ from each other and on which dose levels the fetal doses are estimated to. ... -
DEFORMABLE IMAGE REGISTRATION OF SPINE MAGNETIC RESONANCE IMAGES WITH ELASTIX FOR DETAILED CHARACTERIZATION OF DISC LOADING BEHAVIORS
(2021-05-10)Purpose: This work aimed to develop an optimized strategy for registration of spine magnetic resonance (MR) images acquired with and without spinal loading, as well as evaluate the quality of the registration strategy ... -
APOPTOTIC EFFECTS IN RENAL CORTEX AFTER TREATMENT WITH 177LU-OCTREOTATE
(2021-05-10)Purpose: The purpose of this project was to investigate gene regulation of a predetermined panel of apoptotic genes in murine renal cortex after treatment with 177Lu-octreotate after one day and seven days. Theory: ... -
The value of cardiac MRI texture analysis in patients with clinically suspected myocarditis
(2021-05-10)Purpose: The aim of this proof-of-concept study was to assess the diagnostic value of texture analysis (TA) based on conventional balanced steady-state-free precession (bSSFP), late gadolinium enhancement (LGE) and ...