| 1. |
- Ahlander, Britt-Marie, 1954-, et al.
(författare)
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Development and validation of a questionnaire evaluating patient anxiety during Magnetic Resonance Imaging : the Magnetic Resonance Imaging- Anxiety Questionnaire (MRI-AQ)
- 2016
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Ingår i: Journal of Advanced Nursing. - : Wiley-Blackwell. - 0309-2402 .- 1365-2648. ; 72:6, s. 1368-1380
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To develop and validate a new instrument measuring patient anxiety during Magnetic Resonance Imaging examinations, Magnetic Resonance Imaging-Anxiety Questionnaire.Background: Questionnaires measuring patients’ anxiety during Magnetic Resonance Imaging examinations have been the same as used in a wide range of conditions. To learn about patients’ experience during examination and to evaluate interventions, a specific questionnaire measuring patient anxiety during Magnetic Resonance Imaging is needed.Design: Psychometric cross-sectional study with test-retest design.Methods: A new questionnaire, Magnetic Resonance Imaging-Anxiety Questionnaire, was designed from patient expressions of anxiety in Magnetic Resonance Imagingscanners. The sample was recruited between October 2012–October 2014. Factor structure was evaluated with exploratory factor analysis and internal consistency with Cronbach’s alpha. Criterion-related validity, known-group validity and test-retest was calculated.Results: Patients referred for Magnetic Resonance Imaging of either the spine or the heart, were invited to participate. The development and validation of Magnetic Resonance Imaging-Anxiety Questionnaire resulted in 15 items consisting of two factors. Cronbach’s alpha was found to be high. Magnetic Resonance Imaging-Anxiety Questionnaire correlated higher with instruments measuring anxiety than with depression scales. Known-group validity demonstrated a higher level of anxiety for patients undergoing Magnetic Resonance Imaging scan of the heart than for those examining the spine. Test-retest reliability demonstrated acceptable level for the scale.Conclusion: Magnetic Resonance Imaging-Anxiety Questionnaire bridges a gap among existing questionnaires, making it a simple and useful tool for measuring patient anxiety during Magnetic Resonance Imaging examinations.
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| 2. |
- Benedek, Hunor, et al.
(författare)
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Strategies for quality assurance of intensity modulated radiation therapy
- 2015
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Ingår i: 8TH INTERNATIONAL CONFERENCE ON 3D RADIATION DOSIMETRY (IC3DDOSE). - : Institute of Physics (IOP). ; 573, s. 012015-012015
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Konferensbidrag (refereegranskat)abstract
- In late 2011 The Swedish Society of Radiation Physics formed a working group to concentrate on the Quality Assurance of modern radiation therapy techniques. The given task was to identify and summarise the different QA strategies in Sweden and also the international recommendations. This was used to formulate recommendations for practical guidelines within Sweden. In this paper a brief summery of the group's work is presented. All the Swedish radiation therapy centres do a pre treatment verification measurement as QA for every new IMRT and VMAT plan. Physicists do it and they believe it to be time consuming. A general standpoint from all the centres was that new guidelines and legislation is needed to allow QA that does not require a measurement. Based on various international publications and recommendations the working group has presented two strategies, one where all new plans are checked through measurement and one where no measurement is needed. The measurement-based strategy is basically the same as the one used today with an extended machine QA part. The other presented strategy is process oriented where all the different parts of the treatment chain are checked separately. The final report can be found in Swedish on http://www.radiofysik.org.
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| 3. |
- Björkdahl, Ann, 1959-, et al.
(författare)
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Decline in cognitive function due to diffuse axonal injury does not necessarily imply a corresponding decline in ability to perform activities
- 2016
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Ingår i: Disability and Rehabilitation. - : Informa UK Limited. - 0963-8288 .- 1464-5165. ; 38:10, s. 1006-1015
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The study explored the direction of change (decline vs. improvement) after diffuse axonal injury (DAI) in the domains of the ICF: body structure, body function, and activity.Methods: Thirteen patients with DAI were assessed by using diffusion tensor imaging (DTI) to measure body structure, the Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS) to measure body function, and the Assessment of Motor and Process Skills (AMPS) to measure activity. The DTI, BNIS, and AMPS were applied at the acute phase (A1), and at 6 and 12 months post-injury (A2 and A3). Visual and statistical analyses were conducted to explore time-dependent changes in the ICF domains.Results: Improvements were observed for most patients in all ICF domains from injury until six months. Thereafter, the results diverged, with half of the subjects showing a decline in DTI and BNIS scores between A2–A3, and all but one of the patients exhibiting identical or better A2–A3 AMPS process skill scores.Conclusions: From 6 to 12 months post-injury, some patients underwent an ongoing degenerative process, causing a decline in cognitive function. The same decline was not observed in the activity measure, which might be explained by the use of compensatory strategies.Implications for rehabilitationIn rehabilitation it is essential to be aware that in some cases with TBI, an ongoing degenerative process in the white matter can be expected, causing an adverse late effect on cognitive function.The cognitive decline, caused by DAI, does not necessarily mean a concurrent decrease in activity performance, possibly explained by the use of compensatory strategies. This suggests that, after the post-acute phase, rehabilitation offering strategy training may be beneficial to enhance every-day functioning.Strategy use requires awareness, which imply the need to assess level of awareness in order to guide rehabilitation.
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| 4. |
- Deyhle Jr, Richard
(författare)
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Cross-modal Imaging in Lung Research: From µCT dosimetry to synchrotron phase contrast microtomography biomechanical insights in preclinical lung injury models
- 2024
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lung diseases continue to present a large burden to public health, especially in industrialized countries. For abetter understanding of the underlying patho-mechanisms in lung related diseases as well as for testing theefficacy of novel therapies, preclinical studies in animal models are indispensable. The significance of preclinical X-ray based micro-computed tomography (µCT) research lies in its ability to provide high-resolution, non-invasive lung imaging of small animals as the air inside the lung acts as a natural contrast and to image the lung parenchyma longitudinally to assess functional and morphological alterations and test efficacy of therapeutic interventions. This often requires requires imaging protocols that balance between sufficient image quality and clinically relevant radiation absorbed doses. A reproducible method for evaluation of absorbed radiation absorbed doses is desirable. Absorbed radiation absorbed doses were measured in a polymethyl methacrylate (PMMA) phantom using standard TLD and a novel type of OSLD made form household salt. Four imaging protocols from MILabs “xUHR-µCT” scanner were tested. A large discrepancy was observed from results compared to vendor-provided values. The results indicate a need for thorough empirical dose measurements prior to performing longitudinal studies. Four-dimensional imaging, allows for investigation of the dynamics of regional lung functional parameters simultaneously with structural deformation of the lung as a function of time. It is of significant interest to have direct visualization and quantification of interstitial lung diseases at spatial resolutions beyond the capabilities of clinical and conventional absorption-based only CT. Thus far, the high intensity of synchrotron X-ray light sources offer a tool to investigate dynamic morphological and mechanistic features, enabling dynamic in-vivo microscopy. This investigation elucidates the direct effects of interventions targeting the pathophysiology of Acute Respiratory Distress Syndrome (ARDS) and Ventilator-Induced Lung Injury (VILI) on the terminal airways and alveolar microstructure within intact lungs. In such conditions, the relationship between microscopic strain within the mechanics of the alveolar structure and the broader mechanical characteristics and viscoelastic properties of the lungs remains poorly understood. A time-resolved synchrotron phase-contrast micro-computed tomography imaging acquisition protocol based on the synchronization between the mechanical ventilation and the cardiac activity was used to resolve the lung parenchyma motion with an effective isotropic voxel size of 6 µm. Quantitative maps of microscopic local lung tissue strain within aerated lung alveolar tissue under protective mechanical ventilation in anesthetized rats were obtained. This approach was used to assess the effect of alterations in lung tissue biomechanics induced by lung injury at 7 days after single-dose, intratracheal bleomycin instillation in combination with short-term high-tidal volume (VT) mechanical ventilation. Overall, this work address the aspects of radiation exposure to in experimental imaging of small animals and lays a foundation for a more nuanced understanding of lung injury and mechanical ventilation. In the future, it may result in a more effective and less injurious respiratory support for patients with acute lung injury or chronic lung diseases.
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| 5. |
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| 6. |
- Strand, Fredrik, et al.
(författare)
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Så kan AI valideras för klinisk implementering
- 2023
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Ingår i: Lakartidningen. - : Sveriges läkarförbund. - 0023-7205 .- 1652-7518. ; 120
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Tidskriftsartikel (refereegranskat)abstract
- Företag marknadsför över 200 mjukvaror för artificiell intelligens (AI) inom radiologi.Vårdgivare behöver ha möjlighet till opartisk och kvalitetssäkrad utvärdering.Projektet Validering av AI inom bröstradiologi (VAI-B) startades för att möta detta behov, initialt inom mammografiscreening.
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| 7. |
- Dalmo, Johanna, et al.
(författare)
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Potential renal toxicity biomarkers indicating radiation injury after 177Lu-octreotate treatment
- 2013
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Ingår i: Annual congress of the European association of nuclear medicine, october 19-23, 2013, Lyon, France. Posterwalk.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The kidneys are one of the most exposed non-tumor tissues and regarded as one of the main dose-limiting organs in peptide receptor radionuclide therapy (PRRT). [177Lu-DOTA0, Tyr3]-octreotate (177Lu-octreotate) has shown promising results in the treatment of somatostatin receptor overexpressing neuroendocrine tumors, but optimization is still needed. The ability to give each patient as much 177Lu-octreotate as possible without inducing nephrotoxicity is necessary for an efficient treatment. However, due to large inter-individual differences in uptake and retention in the kidneys, there is a need for efficient Methods that early can indicate renal injury. A possible way is to identify biomarkers for high risk of radiation nephrotoxicity. The aim of this study was to investigate the potential of using urinary retinol binding protein (RBP), and blood valinhydantoin (VH) as biomarkers of nephrotoxicity on adult mice after 177Lu-octreotate treatment. BALB/c nude mice (n=6/group) were i.v. injected with 60 MBq or 120 MBq of 177Lu-octreotate. The control group was mock treated with saline. Spot urine samples were collected before injection, and 14, 30, 60 and 90 days after injection. Analysis of RBP4 and creatinine was performed using Mouse RBP4 ELISA kit and Creatinine kit from R&D Systems, respectively. Erythrocytes were separated from whole blood samples collected 90 days after injection, and analysed for VH by LC-MS/MS. The ratio between VH and a volumetric standard was calculated. The RBP/creatinine level increased with time in both groups given 177Lu-octreotate, with earlier and higher response for the 120 MBq group. No clear change in VH level between the different groups was observed. The result show that RBP may be a promising new biomarker for radiation induced kidney toxicity. The presently used method based on VH was not sensitive enough to be used as kidney toxicity marker. Further studies on mice are ongoing to validate if RBP4 may be efficient in predicting late nephrotoxicity. In patients, RBP/creatinine levels are followed in urine samples after treatment with 177Lu-octreotate.
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| 8. |
- Janek, Sara, 1977-, et al.
(författare)
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Development of dose delivery verification by PET imaging of photonuclear reactions following high energy photon therapy
- 2006
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Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 0031-9155 .- 1361-6560. ; 51:22, s. 5769-
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Tidskriftsartikel (refereegranskat)abstract
- A method for dose delivery monitoring after high energy photon therapy has been investigated based on positron emission tomography (PET). The technique is based on the activation of body tissues by high energy bremsstrahlung beams, preferably with energies well above 20 MeV, resulting primarily in 11C and 15O but also 13N, all positron-emitting radionuclides produced by photoneutron reactions in the nuclei of 12C, 16O and 14N. A PMMA phantom and animal tissue, a frozen hind leg of a pig, were irradiated to 10 Gy and the induced positron activity distributions were measured off-line in a PET camera a couple of minutes after irradiation. The accelerator used was a Racetrack Microtron at the Karolinska University Hospital using 50 MV scanned photon beams. From photonuclear cross-section data integrated over the 50 MV photon fluence spectrum the predicted PET signal was calculated and compared with experimental measurements. Since measured PET images change with time post irradiation, as a result of the different decay times of the radionuclides, the signals from activated 12C, 16O and 14N within the irradiated volume could be separated from each other. Most information is obtained from the carbon and oxygen radionuclides which are the most abundant elements in soft tissue. The predicted and measured overall positron activities are almost equal (−3%) while the predicted activity originating from nitrogen is overestimated by almost a factor of two, possibly due to experimental noise. Based on the results obtained in this first feasibility study the great value of a combined radiotherapy–PET–CT unit is indicated in order to fully exploit the high activity signal from oxygen immediately after treatment and to avoid patient repositioning. With an RT–PET–CT unit a high signal could be collected even at a dose level of 2 Gy and the acquisition time for the PET could be reduced considerably. Real patient dose delivery verification by means of PET imaging seems to be applicable provided that biological transport processes such as capillary blood flow containing mobile 15O and 11C in the activated tissue volume can be accounted for.
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