| 11. |
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| 12. |
- Andersson, Karin M., 1989-, et al.
(författare)
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Evaluation of a metal artifact reduction algorithm in CT studies used for proton radiotherapy treatment planning
- 2014
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Ingår i: Journal of Applied Clinical Medical Physics. - : John Wiley & Sons. - 1526-9914. ; 15:5, s. 112-119
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Tidskriftsartikel (refereegranskat)abstract
- Metal objects in the body such as hip prostheses cause artifacts in CT images. When CT images degraded by artifacts are used for treatment planning of radiotherapy, the artifacts can yield inaccurate dose calculations and, for particle beams, erroneous penetration depths. A metal artifact reduction software (O-MAR) installed on a Philips Brilliance Big Bore CT has been tested for applications in treatment planning of proton radiotherapy. Hip prostheses mounted in a water phantom were used as test objects. Images without metal objects were acquired and used as reference data for the analysis of artifact-affected regions outside of the metal objects in both the O-MAR corrected and the uncorrected images. Water equivalent thicknesses (WET) based on proton stopping power data were calculated to quantify differences in the calculated proton beam penetration for the different image sets. The WET to a selected point of interest between the hip prostheses was calculated for several beam directions of clinical relevance. The results show that the calculated differences in WET relative to the reference case were decreased when the O-MAR algorithm was applied. WET differences up to 2.0 cm were seen in the uncorrected case while, for the O-MAR corrected case, the maximum difference was decreased to 0.4 cm. The O-MAR algorithm can significantly improve the accuracy in proton range calculations. However, there are some residual effects, and the use of proton beam directions along artifact streaks should only be used with caution and appropriate margins.
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| 13. |
- Andersson, Karin M., 1989-, et al.
(författare)
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Evaluation of two commercial CT metal artifact reduction algorithms for use in proton radiotherapy treatment planning in the head and neck area
- 2018
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Ingår i: Medical physics (Lancaster). - : Wiley-Blackwell Publishing Inc.. - 0094-2405 .- 2473-4209. ; 45:10, s. 4329-4344
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To evaluate two commercial CT metal artifact reduction (MAR) algorithms for use in proton treatment planning in the head and neck (H&N) area.METHODS: An anthropomorphic head phantom with removable metallic implants (dental fillings or neck implant) was CT-scanned to evaluate the O-MAR (Philips) and the iMAR (Siemens) algorithms. Reference images were acquired without any metallic implants in place. Water equivalent thickness (WET) was calculated for different path directions and compared between image sets. Images were also evaluated for use in proton treatment planning for parotid, tonsil, tongue base, and neck node targets. The beams were arranged so as to not traverse any metal prior to the target, enabling evaluation of the impact on dose calculation accuracy from artifacts surrounding the metal volume. Plans were compared based on γ analysis (1 mm distance-to-agreement/1% difference in local dose) and dose volume histogram metrics for targets and organs at risk (OARs). Visual grading evaluation of 30 dental implant patient MAR images was performed by three radiation oncologists.RESULTS: In the dental fillings images, ΔWET along a low-density streak was reduced from -17.0 to -4.3 mm with O-MAR and from -16.1 mm to -2.3 mm with iMAR, while for other directions the deviations were increased or approximately unchanged when the MAR algorithms were used. For the neck implant images, ΔWET was generally reduced with MAR but residual deviations remained (of up to -2.3 mm with O-MAR and of up to -1.5 mm with iMAR). The γ analysis comparing proton dose distributions for uncorrected/MAR plans and corresponding reference plans showed passing rates >98% of the voxels for all phantom plans. However, substantial dose differences were seen in areas of most severe artifacts (γ passing rates of down to 89% for some cases). MAR reduced the deviations in some cases, but not for all plans. For a single patient case dosimetrically evaluated, minor dose differences were seen between the uncorrected and MAR plans (γ passing rate approximately 97%). The visual grading of patient images showed that MAR significantly improved image quality (P < 0.001).CONCLUSIONS: O-MAR and iMAR significantly improved image quality in terms of anatomical visualization for target and OAR delineation in dental implant patient images. WET calculations along several directions, all outside the metallic regions, showed that both uncorrected and MAR images contained metal artifacts which could potentially lead to unacceptable errors in proton treatment planning. ΔWET was reduced by MAR in some areas, while increased or unchanged deviations were seen for other path directions. The proton treatment plans created for the phantom images showed overall acceptable dose distributions differences when compared to the reference cases, both for the uncorrected and MAR images. However, substantial dose distribution differences in the areas of most severe artifacts were seen for some plans, which were reduced by MAR in some cases but not all. In conclusion, MAR could be beneficial to use for proton treatment planning; however, case-by-case evaluations of the metal artifact-degraded images are always recommended.
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| 14. |
- Andersson, Sten-Ove, et al.
(författare)
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Doctors’ and Nurses’ Perceptions of Military Pre-hospital Emergency Care
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this study was to identify physicians’ and nurses’ perceptions of military prehospital emergency care before and after an international mission. A qualitative empirical study with a phenomenographic approach was used. The aim is to identify the area of knowledge, pre-hospital care in a military environment, in terms of expressions from doctors and nurses focussing on the variation in how learning of pre-hospital care is perceived. The result of the study is a set of descriptive categories on a collective level, showing the variation in how doctors and nurses perceived the phenomenon of military pre-hospital emergency care. The results after predeployment training can be categorized as (1) to learn military medicine, (2) to take care of the casualty and (3) to have safety awareness. The results after an international mission can be categorized as (1) to collaborate with others, (2) to deliver general health care, and (3) to improve competence in military medicine. Possible implications of the results from the present study are the following; (I) better conditions for doctors and nurses to provide appropriate military medical care by clarification and better understanding of professions in the mission area (doctors, nurses, officers), since they may have different goals for their actions, (II) to pay attention to all aspects of military health care during predeployment training, including general health care in the mission area, (III) to implement new knowledge in military medicine in the predeployment training, and (IV) to train for the reality all doctors and nurses are about to meet. These results indicate that the training should be developed in order to optimize the prepare physicians and nurses for international assignments. This may result in increased safety for the provider of care, while at the same time minimizing suffering and enhancing the possibility of survival of the injured.
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| 15. |
- Andersson, Sten-Ove, et al.
(författare)
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Doctors' and nurses' perceptions of military pre-hospital emergency care - When training becomes reality
- 2017
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Ingår i: International Emergency Nursing. - : Elsevier. - 1755-599X .- 1878-013X. ; 32, s. 70-77
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Forskningsöversikt (refereegranskat)abstract
- The aim of this study was to identify physicians' and nurses' perceptions of military pre-hospital emergency care before and after an international mission. A qualitative empirical study with a phenomeno-graphic approach was used. The results after pre-deployment training can be categorised as (1) learning about military medicine and (2) taking care of the casualty. The results after an international mission can be categorised as (1) collaborating with others, (2) providing general health care and (3) improving competence in military medicine. These results indicate that the training should be developed in order to optimise pre-deployment training for physicians and nurses. This may result in increased safety for the provider of care, while at the same time minimising suffering and enhancing the possibility of survival of the injured. (C) 2017 Elsevier Ltd. All rights reserved.
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| 16. |
- Andersson, Sten-Ove, et al.
(författare)
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Fixing the wounded or keeping lead in the air-tactical officers' views of emergency care on the battlefield.
- 2015
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Ingår i: Military medicine. - : Association of Military Surgeons Us. - 0026-4075 .- 1930-613X. ; 180:2, s. 224-229
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to identify tactical officers' views of prehospital emergency care in the field before an international mission. A qualitative study with a phenomenographic approach based on interviews was used. The result of this study is a set of descriptive categories on a collective level, showing the variation in how the tactical officers perceived the phenomenon of emergency care in the battlefield. The result can be viewed as (1) noncombat-oriented including being able to do one's specialist task, being able to talk with local people, and being able to give first aid, and (2) combat-oriented including soldiers' skills and roles in the unit, being able to act in the unit, and being able to lead the care of injured. These findings are important for officers' preparation for international missions. The interaction between military and medical knowledge on-site care should be developed between the tactical officer and the medical personnel in order to minimize suffering and to enhance the possibility for survival of the casualty.
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| 17. |
- Andersson, Sten-Ove, et al.
(författare)
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Interaction, Action, and Reflection : How Medics Learn Medical Care in the Swedish Armed Forces
- 2013
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Ingår i: Military medicine. - : Association of Military Surgeons of the U S. - 0026-4075 .- 1930-613X. ; 178:8, s. 861-866
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study is to examine how medics within the Swedish Armed Forces perceive their learning outcome following military prehospital training. A qualitative study with a phenomenographic approach was used to investigate how learning is perceived among military medics. At meta level, the results can be viewed as an interaction, i.e., being able to collaborate in the medical platoon, including the ability to interact within the group and being able to lead; an action, i.e., being able to assess and treat casualties, including the ability to communicate with the casualty, to prioritize, and to be able to act; and a reflection, i.e., having confidence in one's own ability in first aid, including being prepared and feeling confident. interaction during the period of education is important for learning. action, being able to act in the field, is based on a drill in which the subject progresses from simple to complex procedures. reflection, learning to help others, is important for confidence, which in turn creates preparedness, thereby making the knowledge meaningful.
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| 18. |
- Axelsson, Susanna, et al.
(författare)
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Effect of combined caries-preventive methods: a systematic review of controlled clinical trials.
- 2004
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Ingår i: Acta odontologica Scandinavica. - : Informa UK Limited. - 0001-6357 .- 1502-3850. ; 62:3, s. 163-9
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Forskningsöversikt (refereegranskat)abstract
- The aim of this systematic review was to evaluate the caries-preventive effect of combined caries-preventive methods, defined as two or more different interventions in combination, each expected to prevent dental caries. The Medline database was searched for articles published in the period January 1966 to June 2003. Twenty-four controlled studies met the inclusion criteria, and their value as evidence was assessed according to predetermined criteria. The level of evidence for the overall conclusion regarding each method was graded according to the protocol of the Swedish Council on Technology Assessment in Health Care. The scientific evidence for the combination of treatments involving fluoride that had a preventive effect on caries in children and adolescents was graded as moderate. However, for elderly patients the scientific evidence for the caries-preventive effect of different combinations of treatments was found to be incomplete. No conclusion could be drawn regarding the evidence for combinations of treatments being effective for groups at high caries risk, as the results from the identified clinical studies were conflicting.
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| 19. |
- Baresel, Christian, et al.
(författare)
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Reuse of treated wastewater for non-potable use (ReUse)
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Population growth, increasing living standards, but also environmental hazards with global climate change as the most significant are all contributing to an increasing water stress in many parts of the world. While access to fresh water for drinking water is getting more costly due to environmental pollution, uses of drinking water conflicts with water needs for agricultural and industrial use, which are in need of substantial water quantities. The use of reclaimed wastewater for non-potable purposes provides a solution for this. This is not new and has in fact been applied in many regions as the main water management approach. As water scarcity becomes more severe, also the need for more sustainable and holistic approaches to deal with our limited fresh water resources becomes more and more obvious. The traditional one-way water handling approach, with end-of-pipe treatment releasing “clean” effluent water to nature, has to be converted into a society-internal water reuse scheme where different water qualities and water uses are considered as an integral part of the water cycle. The present report presents activities and results from an international project that aimed at developing and optimizing water treatment processes and systems for sustainable reuse of treated wastewater. The starting point is to combine the sequential batch treatment (SBR, sequencing batch reactors) with different conventional and emerging secondary and tertiary treatment techniques in various combinations, optimized from an overall sustainability perspective. Evaluation and optimization is achieved using life cycle assessment and life cycle cost assessment and their combination. Den här rapporten finns endast på engelska. Svensk sammanfattning finns i rapporten.
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| 20. |
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