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Sökning: WFRF:(Ahlström Håkan)

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41.
  • Andersson, Camilla, et al. (författare)
  • Patient Experience of an 18F-FDG-PET/CT Examination: : Need for Improvements in Patient Care
  • 2015
  • Ingår i: Journal of Radiology Nursing. - : Elsevier. - 1546-0843. ; 34:2, s. 100-108
  • Tidskriftsartikel (refereegranskat)abstract
    • The aims of this study were to investigate the patients' knowledge about and experience of an 18F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) examination and to investigate the self-reported feelings of stress, level of physical activity, and health-related quality of life (HRQoL) and to find out if this was related to how they experienced the examination. A cross-sectional survey was used to collect information on 198 patients with known or suspected malignancy. As many as 32% to 63% were satisfied with the nursing staff, the communication, and the professional skills. Most patients did not know beforehand what an FDG-PET/CT examination was. The HRQoL, level of perceived stress, and physical activity were relatively low. A better HRQoL, lower level of perceived stress, and a higher level of physical activity were correlated to a more positive experience and higher education to more knowledge about the examination (p < .01–.05). The information before the examination needs to be improved. The results may be used to improve patient care and optimize imaging procedures.
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42.
  • Andersson, Camilla (författare)
  • PET/CT in oncology : Patient experience, image quality and the value of information
  • 2018
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The overall aim was to investigate patients’ experiences with a PET/CT examination, satisfaction with care provided in connection to the examination and whether web-based information can improve satisfaction with care and image quality, compared to standard care. An additional aim was to explore how satisfaction with care and image quality is associated with health-related quality of life (HRQoL) and perceived stress. Methods: Study I and IV included patients with known or suspected malignancy scheduled for an 18F-FDG PET/CT examination. Study II included prostate cancer patients with known or suspected bone metastases scheduled for an 18F-fluoride PET/CT examination, and study III included head and neck cancer patients scheduled for an 18F-FDG PET/CT examination in a fixation mask. Study I and II had cross-sectional designs, study III used a phenomenological methodology according to Max van Manen, and study IV was a randomized controlled trial. Results: Study I and II found that many patients did not know before what a PET/CT examination was but were satisfied with care provided by the nursing staff. In study II the image quality was high and there was no difference in image quality between those patients that experienced pain or discomfort during the PET/CT and those that did not. Study III showed that the patient’s lifeworld was changed during the PET/CT examination and the use of coping strategies helped the patient to endure the examination procedure. In study IV the overall satisfaction, satisfaction single-variables and image quality was high in the intervention group and standard care group. There was no statistically significant difference between patients the intervention group and standard care group. However, there was slightly higher number of detected image quality defects in the standard care group. In study I and IV there were some statistically significant correlations between patient satisfaction and HRQoL (p<0.01-0.05). Conclusion: The results of this thesis may be used to improve patient information and care in connection to PET/CT examinations and thereby help optimize PET/CT imaging procedure. However, the results need to be investigated in larger populations.
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43.
  • Andersson, Camilla, et al. (författare)
  • Randomized Controlled Trial Examining Effects of Web-Based Information on Patient Satisfaction and Image Quality in 18F-FDG PET/CT Examinations
  • 2019
  • Ingår i: Journal of Nuclear Medicine Technology. - : Society of Nuclear Medicine. - 0091-4916 .- 1535-5675. ; :1, s. 36-46
  • Tidskriftsartikel (refereegranskat)abstract
    • Our aim was to compare the effect that having access, versus not having access, to web-based patient information on 18F-FDG PET/CT has on image quality and on patient satisfaction with their care during and knowledge about the examination, as well as to explore whether patients utilized and were satisfied with the web-based information.Methods: We recruited 148 patients between October 2015 and December 2016 and randomly assigned them to a standard-care group or an intervention group. Both groups received standard information about the 18F-FDG PET/CT examination, but the intervention group also received access to web-based information. A questionnaire was used to evaluate patient satisfaction with, knowledge about, and discomfort during the examination, and a masked assessment of image quality was conducted.Results: Overall satisfaction was high in both groups. The lowest satisfaction was with information about how the patients would receive the results of the examination. More patients in the intervention group than in the standard-care group knew how the 18F-FDG PET/CT examination would be conducted. Descriptive data suggest that image quality was slightly better in the intervention group than in the standard-care group, but none of the outcomes significantly differed between the groups. However, several obstacles were encountered during recruitment that led to insufficient power to detect differences. Also, only 54 of 75 patients (72%) in the intervention group utilized the web-based information. However, those who did utilize the information were satisfied with it and found it helpful.Conclusion: The effects of web-based information need to be investigated in a larger sample of patients. Having access to improved information before undergoing 18F-FDG PET/CT may help patients prepare for and undergo the examination. It may also improve image quality. However, this possibility needs to be investigated using image quality as the primary outcome. The results may be used to improve patient information and care and thereby optimize the 18F-FDG PET/CT procedure.
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44.
  • Andersson, Jonathan, et al. (författare)
  • Estimating the cold-induced brown adipose tissue glucose uptake rate measured by 18F-FDG PET using infrared thermography and water-fat separated MRI
  • 2019
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
  • Tidskriftsartikel (refereegranskat)abstract
    • Brown adipose tissue (BAT) expends chemical energy to produce heat, which makes it a potential therapeutic target for combating metabolic dysfunction and overweight/obesity by increasing its metabolic activity. The most well-established method for measuring BAT metabolic activity is glucose uptake rate (GUR) measured using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). However, this is expensive and exposes the subjects to potentially harmful radiation. Cheaper and safer methods are warranted for large-scale or longitudinal studies. Potential alternatives include infrared thermography (IRT) and magnetic resonance imaging (MRI). The aim of this study was to evaluate and further develop these techniques. Twelve healthy adult subjects were studied. The BAT GUR was measured using 18F-FDG PET during individualized cooling. The temperatures of the supraclavicular fossae and a control region were measured using IRT during a simple cooling protocol. The fat fraction and effective transverse relaxation rate of BAT were measured using MRI without any cooling intervention. Simple and multiple linear regressions were employed to evaluate how well the MRI and IRT measurements could estimate the GUR. Results showed that both IRT and MRI measurements correlated with the GUR. This suggest that these measurements may be suitable for estimating the cold-induced BAT GUR in future studies.
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45.
  • Andersson, Jonathan, et al. (författare)
  • MRI estimates of brown adipose tissue in children - Associations to adiposity, osteocalcin, and thigh muscle volume
  • 2019
  • Ingår i: Magnetic Resonance Imaging. - : Elsevier BV. - 0730-725X .- 1873-5894. ; 58, s. 135-142
  • Tidskriftsartikel (refereegranskat)abstract
    • Context Brown adipose tissue is of metabolic interest. The tissue is however poorly explored in children. Methods: Sixty-three 7-year old subjects from the Swedish birth-cohort Halland Health and Growth Study were recruited. Care was taken to include both normal weight and overweight children, but the subjects were otherwise healthy. Only children born full term were included. Water-fat separated whole-body MRI scans, anthropometric measurements, and measurements of fasting glucose and levels of energy homeostasis related hormones, including the insulin-sensitizer osteocalcin, were performed. The fat fraction (FF) and effective transverse relaxation time (T-2(star)) of suspected brown adipose tissue in the cervical-supraclavicular-axillary fat depot (sBAT) and the FFs of abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) were measured. Volumes of sBAT, abdominal VAT and SAT, and thigh muscle volumes were measured. Results: The FF in the sBAT depot was lower than in VAT and SAT for all children. In linear correlations including sex and age as explanatory variables, sBAT FF correlated positively with all measures of adiposity (p < 0.01), except for VAT FF and weight, positively with sBAT T-2* (p = 0.036), and negatively with osteocalcin (p = 0.017). When adding measures of adiposity as explanatory variables, sBAT FF also correlated negatively with thigh muscle volume (p < 0.01). Conclusions: Whole-body water-fat MRI of children allows for measurements of sBAT. The FF of sBAT was lower than that of VAT and SAT, indicating presence of BAT. Future studies could confirm whether the observed correlations corresponds to a hormonally active BAT.
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46.
  • Andersson, Jonathan, et al. (författare)
  • Separation of water and fat signal in whole-body gradient echo scans using convolutional neural networks
  • 2019
  • Ingår i: Magnetic Resonance in Medicine. - : Wiley. - 0740-3194 .- 1522-2594. ; 82:3, s. 1177-1186
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To perform and evaluate water–fat signal separation of whole‐body gradient echo scans using convolutional neural networks.Methods: Whole‐body gradient echo scans of 240 subjects, each consisting of 5 bipolar echoes, were used. Reference fat fraction maps were created using a conventional method. Convolutional neural networks, more specifically 2D U‐nets, were trained using 5‐fold cross‐validation with 1 or several echoes as input, using the squared difference between the output and the reference fat fraction maps as the loss function. The outputs of the networks were assessed by the loss function, measured liver fat fractions, and visually. Training was performed using a graphics processing unit (GPU). Inference was performed using the GPU as well as a central processing unit (CPU).Results: The loss curves indicated convergence, and the final loss of the validation data decreased when using more echoes as input. The liver fat fractions could be estimated using only 1 echo, but results were improved by use of more echoes. Visual assessment found the quality of the outputs of the networks to be similar to the reference even when using only 1 echo, with slight improvements when using more echoes. Training a network took at most 28.6 h. Inference time of a whole‐body scan took at most 3.7 s using the GPU and 5.8 min using the CPU.Conclusion: It is possible to perform water–fat signal separation of whole‐body gradient echo scans using convolutional neural networks. Separation was possible using only 1 echo, although using more echoes improved the results.
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47.
  • Andersson, Jonathan, et al. (författare)
  • Water-fat separation incorporating spatial smoothing is robust to noise
  • 2018
  • Ingår i: Magnetic Resonance Imaging. - : Elsevier BV. - 0730-725X .- 1873-5894. ; 50, s. 78-83
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: To develop and evaluate a noise-robust method for reconstruction of water and fat images for spoiled gradient multi-echo sequences.METHODS: The proposed method performs water-fat separation by using a graph cut to minimize an energy function consisting of unary and binary terms. Spatial smoothing is incorporated to increase robustness to noise. The graph cut can fail to find a solution covering the entire image, in which case the relative weighting of the unary term is iteratively increased until a complete solution is found. The proposed method was compared to two previously published methods. Reconstructions were performed on 16 cases taken from the 2012 ISMRM water-fat reconstruction challenge dataset, for which reference reconstructions were provided. Robustness towards noise was evaluated by reconstructing images with different levels of noise added. The percentage of water-fat swaps were calculated to measure performance.RESULTS: At low noise levels the proposed method produced similar results to one of the previously published methods, while outperforming the other. The proposed method significantly outperformed both of the previously published methods at moderate and high noise levels.CONCLUSION: By incorporating spatial smoothing, an increased robustness towards noise is achieved when performing water-fat reconstruction of spoiled gradient multi-echo sequences.
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48.
  • Andersson, Jonathan (författare)
  • Water–fat separation in magnetic resonance imaging and its application in studies of brown adipose tissue
  • 2019
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Virtually all the magnetic resonance imaging (MRI) signal of a human originates from water and fat molecules. By utilizing the property chemical shift the signal can be separated, creating water- and fat-only images. From these images it is possible to calculate quantitative fat fraction (FF) images, where the value of each voxel is equal to the percentage of its signal originating from fat. In papers I and II methods for water–fat signal separation are presented and evaluated.The method in paper I utilizes a graph-cut to separate the signal and was designed to perform well even for a low signal-to-noise ratio (SNR). The method was shown to perform as well as previous methods at high SNRs, and better at low SNRs.The method presented in paper II uses convolutional neural networks to perform the signal separation. The method was shown to perform similarly to a previous method using a graph-cut when provided non-undersampled input data. Furthermore, the method was shown to be able to separate the signal using undersampled data. This may allow for accelerated MRI scans in the future.Brown adipose tissue (BAT) is a thermogenic organ with the main purpose of expending chemical energy to prevent the body temperature from falling too low. Its energy expending capability makes it a potential target for treating overweight/obesity and metabolic dysfunctions, such as type 2 diabetes. The most well-established way of estimating the metabolic potential of BAT is through measuring glucose uptake using 18F-fludeoxyglucose (18F-FDG) positron emission tomography (PET) during cooling. This technique exposes subjects to potentially harmful ionizing radiation, and alternative methods are desired. One alternative method is measuring the BAT FF using MRI.In paper III the BAT FF in 7-year olds was shown to be negatively associated with blood serum levels of the bone-specific protein osteocalcin and, after correction for adiposity, thigh muscle volume. This may have implications for how BAT interacts with both bone and muscle tissue.In paper IV the glucose uptake of BAT during cooling of adult humans was measured using 18F-FDG PET. Additionally, their BAT FF was measured using MRI, and their skin temperature during cooling near a major BAT depot was measured using infrared thermography (IRT). It was found that both the BAT FF and the temperature measured using IRT correlated with the BAT glucose uptake, meaning these measurements could be potential alternatives to 18F-FDG PET in future studies of BAT.
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49.
  • Andrén, Ulla, 1955-, et al. (författare)
  • Utveckling av ett nytt yrke inom socialpsykiatrisk vård
  • 2019
  • Rapport (övrigt vetenskapligt/konstnärligt)abstract
    • The program in Social Psychiatric Care is a three-year program at the university level leading to a vocational qualification in social psychiatric care and a bachelor's degree in the field of Health Sciences. Until the spring of 2018, six litters have graduated. Students in the social psychiatric care program often have personal interest, previous professional experience from the business areas or inspiration from related friends working in the field of activity. Personal experiences of problems in the fields of activity are also prominent among the students. Students believe that personal experience, willingness and ability is important in order to work within the profession. Characteristics of the students are also an interest and a clear empathetic willingness to work with people and they consider that the profession primarily requires characteristics such as altruism, empathy, social skills and deeper knowledge and understanding in the field. Upon completion of education, students want a career role where they can help other people, feel motivated, or they aim for specific positions or areas of activity. Both managers and alumni from the Social Psychiatric Care program value the broad professional competence that the program leads to. Psychiatric competence is emphasized as particularly valuable by both alumni and managers. This competence means that they also complement the other professions in the activities. Students consider themselves possessed a professional identity that involves introducing psychiatric and custody skills to organizations that previously lacked these perspectives. Something that also brings new approaches to patients, users and clients. Being able to use knowledge from several disciplines are considered to be a strength and competence that are well-needed in environments where people with mental ill health are cared for. The alumni perceive their knowledge as both interdisciplinary and interprofessional.
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50.
  • Benedict, Christian, et al. (författare)
  • Association between physical activity and brain health in older adults
  • 2013
  • Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 34:1, s. 83-90
  • Tidskriftsartikel (refereegranskat)abstract
    • In the present cross-sectional study, we examined physical activity (PA) and its possible association with cognitive skills and brain structure in 331 cognitively healthy elderly. Based on the number of self-reported light and hard activities for at least 30 minutes per week, participants were assigned to 4 groups representing different levels of PA. The cognitive skills were assessed by the Mini Mental State Examination score, a verbal fluency task, and the Trail-making test as a measure of visuospatial orientation ability. Participants also underwent a magnetic resonance imaging of the brain. Multiple regression analysis revealed that greater PA was associated with a shorter time to complete the Trail-making test, and higher levels of verbal fluency. Further, the level of self-reported PA was positively correlated with brain volume, white matter, as well as a parietal lobe gray matter volume, situated bilaterally at the precuneus. These present cross-sectional results indicate that PA is a lifestyle factor that is linked to brain structure and function in late life.
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