| 11. |
|
|
| 12. |
- Alshamari, Muhammed, 1975-
(författare)
-
Low-dose computed tomography of the abdomen and lumbar spine
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Radiography is a common radiologic investigation despite abundant evidence of its limited diagnostic value. On the other hand, computed tomography (CT) has a high diagnostic value and is widely considered to be among the most important advances in medicine. However, CT exposes patients to a higher radiation dose and it might therefore not be acceptable simply to replace radiography with CT, despite the powerful diagnostic value of this technique. At the expense of reduced CT image quality, which could be adjusted to the diagnostic needs, low-dose CT of abdomen and lumbar spine can be performed at similar dose to radiography. The aim of the current thesis project was to evaluate low-dose CT of the abdomen and lumbar spine and to compare it with radiography. The hypothesis was that CT would give better image quality and diagnostic information compared to radiography at similar dose levels. Firstly, the diagnostic accuracy of low-dose CT of the abdomen was evaluated. Results showed that low-dose CT of abdomen has a high sensitivity and specificity compared to radiography, i.e., it has higher diagnostic accuracy. Similar results were obtained from our systematic review. Secondly, in a phantom study, an ovine phantom was scanned at various CT settings. The image quality was evaluated to obtain a protocol for the optimal settings for low-dose CT of lumbar spine at 1 mSv. This new protocol was then used in a clinical study to assess the image quality of low-dose CT of the lumbar spine and compare it to radiography. Results showed that low-dose CT has significantly better image quality than radiography. Finally, the impact of Iterative reconstruction (IR) on image quality of lumbar spine CT was tested. Iterative reconstruction is a recent CT technique aimed to reduce radiation dose and/or improve image quality. The results showed that the use of medium strength IR levels in the reconstruction of CT image improves image quality compared to filtered back projection. In conclusion, low-dose CT of the abdomen and lumbar spine, at about 1 mSv, has better image quality and gives diagnostic information compared to radiography at similar dose levels and it could therefore replace radiography.
|
|
| 13. |
- Amcoff, Karin, 1975-
(författare)
-
Serological and faecal biomarkers in inflammatory bowel disease
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are relapsing and remitting disorders characterised by chronic inflammation at various sites in the gastrointestinal tract, resulting in diarrhoea and abdominal pain. Neither the aetiology nor the pathophysiology is yet fully understood, and there is currently no cure.The overall aim of this thesis was to add a piece of the puzzle to understanding the complex pathogenesis of IBD; to determine the role of genetic and environmental factors in the development of antibodies in IBD - which could provide insight to the aetiology of the diseases; and to find sensitive and specific faecal biomarkers to predict future flare in the diseases.By conducting twin-studies, we found that some serological antibodies associated with Crohn's disease seemed to be genetically predisposed (anti-OmpC and anti-I2). Genetic predisposition do not play a predominant role in the generation of other antibodies, such as ASCA, anti-CBir1 or the autoantibody most commonly found in ulcerative colitis; pANCA. Exposure to environmental factors during childhood are suggested to be of importance in the development of ASCA and anti-CBir1 in CD. Active smoking seemed to have a protective effect against development of pANCA.Faecal calprotectin is a known marker for intestinal inflammation. In our third study, three faecal calprotectin assays were compared, which revealed overall poor agreement. This implies that standardisation of the method is highly needed.In our final study, we measured faecal eosinophil derived neurotoxin (EDN) and eosinophil cationic protein (ECP) in patients with IBD every third month over a two-year period. The results revealed that the risk of relapse in UC can be predicted by measuring EDN consecutively.
|
|
| 14. |
- Amer, Ahmed, 1984-
(författare)
-
Cross-cultural adaptation and psychometric properties of two questionnaires for the assessment of occupational performance in children with disability : Children's Hand-use Experience Questionnaire (CHEQ) and Pediatric Evaluation of Disability Inventory (PEDI)
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Globally, 93–150 million children live with some form of disability, most of them live in developing countries. Occupational performance describes a person’s ability to execute tasks that are meaningful, in the context in which the person lives. The Children’s Hand-use Experience Questionnaire (CHEQ) and the Pediatric Evaluation of Disability Inventory (PEDI) are measurement tools developed to measure different aspects of occupational performance. However, before using these tools in another cultural context, evidence of validity in that context should be established.The overall aim of this thesis was to investigate the evidence of validity for CHEQ and the Uganda version of PEDI (PEDI-UG).Study I established the validity of revised CHEQ 1.0 for children with unilateral cerebral palsy (CP). The study suggested improvements and inclusion of younger children. This led to the development of CHEQ 2.0, which was culturally adapted and validated for Jordan in Study II. Study III indicated that PEDI-UG had good psychometric properties when tested on typically developing children, and it suggested improvements and further analysis in children with disability. Therefore, study IV investigated the psychometric properties on Ugandan children with CP and confirmed the instrument’s validity. However, the differential item functioning analysis comparing children with CP and typically developing children, and the developmental trajectories for both groups, suggested that a separate conversion table should be used to transform the total sum score from raw scores to a 0–100 scaled score. This thesis shows the importance of cultural adaptations and psychometric validation of measurement tools before they can be used in new cultural contexts. The Arabic CHEQ 2.0and PEDI-UG can be used in the evaluation of rehabilitation interventions and will help to fill the need for measurement tools in these countries.
|
|
| 15. |
- Ander, Fredrik, 1978-
(författare)
-
Perioperative complications in obese patients : A thesis on risk reducing strategies
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aspiration of gastric content and delayed or failed intubation are the leading causes of anesthesia-related mortality and morbidity. In the recovery period, airway obstruction with subsequent hypoxia is a relatively common cause of morbidity, and is highly associated to the amount of opioids administered, especially in obese patients.The overall aim of this thesis was to study these risk factors for airway complications and postoperative hypoxia in obese patients, and to evaluate possible strategies for their prevention.In Study I, intubation times and incidence of failed intubation in obese patients were compared between direct laryngoscopy and videolaryngoscopy with the Stortz® C-MAC™. In Studies II and III, the effect of esmolol vs. remifentanil on the esophageal junction, and the possible analgesic properties of low-dose esmolol vs. placebo were evaluated using high-resolution manometry and the cold pressor test, respectively. Finally, in Study IV, the possible opioid-sparing effect of esmolol after laparoscopic gastric bypass surgery was evaluated.The use of videlaryngoscopy did not shorten intubation times, however appeared to reduce the incidence of failed intubation. Our results also show that esmolol has a favorable profile, compared to remifentanil, with regard to the protection against passive regurgitation and aspiration of gastric content. No analgesic effect of low-dose esmolol was however demonstrated. The intraoperative administration of esmolol instead of remifentanil also did not reduce the requirement of morphine for treatment of post-operative pain.The use of Stortz® C-MAC™ may be recommended for intubation of obese patients. Further studies are however required to clarify the possible role of esmolol in anesthesia.
|
|
| 16. |
- Andersson, Anneli, 1992-
(författare)
-
How is ADHD associated with comorbidities and health related outcomes? : The role of familial factors and ADHD during pregnancy
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder characterized by impaired attention and hyperactivity/impulsivity. ADHD is associated with several comorbidities and health-related outcomes. However, it is uncertain whether ADHD is more strongly associated with certain disorder domains, and whether ADHD-related comorbidities and health-related outcomes is important to consider during pregnancy. Aims: To expand the knowledge regarding the genetic overlap between ADHD and other psychiatric disorder symptoms, and to increase the awareness and understanding related to ADHD in women, with a focus on adverse health behaviors, mental health problems, and pregnancy outcomes. Methods: The present thesis includes one systematic review and metaanalysis (Study I), and three studies based on population-based register data from Sweden (Study II, III, and IV), and Norway (Study II).Results: Individuals with ADHD have an increased liability to meet criteria for externalizing, internalizing and neurodevelopmental disordersymptoms, and these co-occurrences are partly due to shared genetic risks. Further, ADHD is an important risk factor to consider before, during and after pregnancy, as ADHD increases the risk of smoking during pregnancy, mental health problems postpartum, and adverse pregnancy outcomes.Conclusions: The genetic overlaps between ADHD and other psychiatric disorder symptoms were similar across disorder dimensions. Further, results demonstrated that ADHD is an important risk factor to consider in women surrounding pregnancy. These findings point towards the importance of recognizing that women diagnosed with ADHD need to be prioritized and allowed more attention and support by the healthcare system, specifically during their fertile years.
|
|
| 17. |
- Andersson, Gunnel, 1958-
(författare)
-
Urinary incontinence : prevalence, treatment seeking behaviour, experiences, and perceptions among persons with and without urinary leakage
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis is to describe urinary incontinence (UI) from a population perspective and to describe experiences and perceptions of UI from an individual perspective. This includes assessing the prevalence of urinary incontinence as well as describing treatment seeking and experiences of living with UI. A secondary aim was to describe the perception of UI among cultures other than the Swedish mainstream, exemplified in this case by Syrian women living in Sweden. Both quantitative and qualitative methods were used, including questionnaires and interviews. Studies I and II were quantitative studies based on a population-based study. Together with a postal survey on general health and living conditions “Life & Health”, a questionnaire on urinary incontinence was sent out to 15 360 randomly-selected residents aged 18-79 in Orebro County, Sweden. In Study I, UI was found to affect 19%. The majority of the respondents experienced minor problems, and only 18% of those reporting UI wanted treatment. However, there was also a group who reported severe problems, but despite this 42% of them did not want treatment. Study II investigated why people with UI refrain from seeking care and treatment. It was found that the desire for treatment was regulated by the frequency of UI, being restricted from participating in various activities, the degree of inconvenience, and the type of UI. Studies III and IV were both qualitative interview studies, describing older women’s experiences of living with UI (Study III) and Syrian women’s perceptions of UI (Study IV). There were similarities between the results of these two studies; the women described UI as a normal and expected problem, and they knew that the district nurse could prescribe incontinence protections and that treatments existed. In both studies, the women expressed difficulties in making contact with the health care service, while the women who did not speak Swedish (Study IV) also had difficulties due to different communication problems. In conclusion, it is important that health care resources are optimized to identify and meet the needs of those who experience major problems with UI, and that there is awareness of the communication difficulties that can be present in meeting with people who speak other languages. However it is also important not to medicalize those who experience minor problems and who have the desire to manage on their own.
|
|
| 18. |
- Andersson, Karin, 1989-
(författare)
-
Metal artifacts in computed tomography : impact of reduction methods on image quality and radiotherapy treatment planning
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Degradation of image quality by metal artifacts is a common problem in computed tomography (CT) imaging, which can limit the diagnostic value of a CT examination and also introduce inaccuracies in radiotherapy (RT) treatment planning. In recent years, commercial metal artifact reduction (MAR) methods have been launched by several CT vendors. The overall aim of this thesis was to evaluate MAR methods in diagnostic imaging and RT treatment planning.Evaluations of hip prosthesis phantom CT images showed that MAR algorithms in general improved image quality, based on both visual grading analysis and quantitative measures, while the application of virtual monoenergetic reconstructions insufficiently reduced metal artifacts. In some cases additional artifacts were introduced by the MAR algorithms. MAR algorithms were also evaluated in hip prosthesis phantom CT imaging used for proton therapy treatment planning, where improvements in dose calculation accuracy were observed.Studies of Head & Neck (H&N) implant CT images in RT treatment planning were also performed. By visual grading of anatomy visualization with respect to target delineation in dental implant patient images, MAR algorithms were shown to significantly improve image quality. However, only minor effects of H&N implant artifacts on proton dose distributions were seen. The impact might be greater for more severe artifacts than those studied here, and thus further investigations of such cases are needed.In conclusion, MAR algorithms have been shown to enhance image quality for diagnostic applications and to improve anatomy visualization in RT treatment planning. The MAR algorithms led to increased proton dose calculation accuracy in some cases, while in other situations only minor changes were seen.
|
|
| 19. |
- Andersson, Tommy, 1970-
(författare)
-
Atrial fibrillation and cause of death, sex differences in mortality, and anticoagulation treatment in low-risk patients
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Atrial fibrillation (AF) is the most common arrhythmia but information on cause of death in patients with AF is sparse, and whether individuals at low risk of cerebral infarction (CVL) should receive antico-agulant medication is controversial. Studies of sex differences with respect to mortality risk have shown conflicting results.Methods: Data were obtained from Swedish National Registers. In Study I, there were 272 186 AF patients and matched controls and in Studies II and III, 9519 AF patients and no other diagnosis and matched controls. Study IV compared treatment with warfarin to no treatment in 48 433 patients with AF. Hazard ratio (HR) was calculated with 95% confidence intervals and outcome rates as number per 1000 person-years.Results: Ischemic heart disease (IHD) was the most common underlying cause of death and was present in 40.2% of AF patients at a HR of 1.7 (1.4-2.1). CVL/stroke was a cause of death in 13.1%, HR 2.7 (1.8-4.0). Among underlying and contributing causes of death, the most common diagnoses were IHD in 43.5%, HR 1.7 (1.4-2.0) and heart failure in 33.1%, HR 2.9 (2.2-3.7). The HRs for mortality in females with AF in age categories ≤65, 65-74, and 75-85 were 2.15, 1.72, and 1.44, and for males 1.76, 1.36, and 1.24. The rates of mortality in females with AF in age categories 55-64, 65-74, and 75-85 were 6.2, 20.7, and 57.3, and for males 8.5, 27.3, and 64.5. In patients 65-74 years, females with a CHA2DS2-VASc score of 2, and males with a score of 1 receiving warfarin treatment showed a significantly reduced risk of cerebral infarc-tion/stroke, HR 0.46 (0.25-0.83) for females and for males, HR 0.39 (0.21-0.73).Conclusions: Most common causes of death in AF patients were CVL/stroke, heart failure, and IHD. HR of mortality in patients with AF was higher in females than in males but absolute risk was higher in males with AF compared to females with AF. Anticoagulant therapy was benefi-cial in patients ≥65 years, regardless of the CHA2DS2-VASc score.
|
|
| 20. |
- Anderzén-Carlsson, Agneta, 1966-
(författare)
-
Children with cancer : focusing on their fear and on how their fear is handled
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Various fears in children with cancer have previously been identified as a result of studying e.g. symptom experiences, distress and uncertainty within this population. Studies of the meaning the children give to their fear, as well as the handling of their fear seem to be sparse, however. Also, fear has not been an exclusive focus in previous studies. Professionals in clinical practice have pointed to the need for such research, which has prompted the present research work. The overall aim of this thesis was therefore twofold; firstly, the aim was to elucidate fear in children and adolescents with cancer in order to gain an understanding from the perspective of adolescents and parents. Secondly, it was to elucidate parents’ and professionals’ handling of the fear. This in order to gain a deeper understanding of what performances and manners the children and adolescents can face when being fearful. A qualitative descriptive design was adopted in the five included studies. The methods used in the data analysis were phenomenological hermeneutical method (studies I–III) and qualitative content analysis (studies IV–V). In study I six adolescent girls, aged 14–16 years, with experiences of various cancer diagnoses, but now declared fit, were interviewed. The results reveal that they experience their fear as embodied, which in the comprehensive understanding of the results was interpreted as a threat to their personal self, their whole existence. Their fear was seen as a holistic intertwined experience, including fear related to the physical body and to the social self. Also, existential fear was described. Their described experience was interpreted as suffering. Studies II and III share the same data. Fifteen parents of children at various ages with various cancer diagnoses were interviewed in focus groups about their experience of their child’s fear. In study II the result reveals how the parents experienced and understood their child’s fear. The fear was described as a multidimensional phenomenon, which was not always easy to identify. It was contrasted to feelings of unease and to absence of fear. In the comprehensive understanding the fear was interpreted as a suffering, as that was regarded to be what was the common meaning in the narratives. The suffering was interpreted as an ethical demand to the parents to take action. In study III the parents described their actions, i.e. they described how they dealt with the fear. Their actions were described as acting in the best interests of the child, which included striving to make the child feel secure and experience wellbeing, up to a certain point. However, after this point the parents used their parental authority to maintain the child’s physical health rather than trying to prevent or relieve the child’s fear. In the comprehensive understanding the parents’ handling of their child’s fear was interpreted as revealing mercy and as being synonymous with meeting the ethical demand put on them. In study IV ten experienced nurses and physicians were individually interviewed about how they handled fear in children with cancer. The result reveals that the existential issues were dealt with within the relationship with the child, on a sliding scale between closeness and distance, and that the fear related to medical procedures occurred on a continuum between support and lack of support. The various actions involved, and the manner in which these actions were performed, was described. In the observational study (study V) eleven parents and their children as well as eleven health professionals participated. They were observed at children’s routine visits at the outpatient clinic. The aim was to study the interactions related to fear. The result reveals that when children were fearful they expressed this both verbally and non-verbally. The parents’ and professionals’ actions and interactions in these situations were found to be characterized by recognition of the fear or lack of attention to the fear. The findings can contribute to a broadened knowledge on fear in children and adolescents with cancer. Awareness and understanding of the meaning adolescents give to their fear, and furthermore, of the parents’ experience and understanding of their child’s fear can provide tools for interacting with these groups. The findings on how fear is dealt with by the ones children have claimed as important sources for support, can give insights into what the child may face when being fearful. These insights can form the basis for individual, as well as collegial, reflections on what is done when children face fear, how fear is handled on an everyday basis and why it is handled in this way. Such reflections could lead to an ethical awareness of handling fear in children with cancer.
|
|
