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  • 1.
    Aarnio, Mikko
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Visualization of Peripheral Pain Generating Processes and Inflammation in Musculoskeletal Tissue using [11C]-D-deprenyl PET2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An objective visualization and quantification of pain-generating processes in the periphery would alter pain diagnosis and represent an important paradigm shift in pain research. Positron emission tomography (PET) radioligand [11C]-D-deprenyl has shown an elevated uptake in painful inflammatory arthritis and whiplash-associated disorder. However, D-Deprenyl’s molecular binding target and uptake mechanism in inflammation and musculoskeletal injuries are still unknown. The present thesis aimed to gain insight into the mechanisms of D-deprenyl binding and uptake and to verify whether pain-associated sites and inflammation in acute musculoskeletal injury could be visualized, objectively quantified and followed over time with [11C]-D-deprenyl PET-computed tomography (PET/CT).

    To identify the D-deprenyl binding target, a high-throughput analysis and competitive radioligand binding studies were performed. D-deprenyl inhibited monoamine oxidase A (MAO-A) activity by 55%, MAO-B activity by 99% and angiotensin-converting enzyme (ACE) by 70%, which identified these enzymes as higher-affinity targets. Furthermore, radioligand receptor binding assays pointed favorably towards the concept of MAO-B as the primary target. To investigate the biochemical characteristics of the binding site, we used radioligand binding assays to assess differences in the binding profile in inflamed human synovial membranes exhibiting varying levels of inflammation. D-deprenyl bound to a single, saturable population of membrane-bound protein in synovial membrane homogenates and the level of inflammation correlated with an increase in D-deprenyl binding affinity.

    To verify whether D-deprenyl can visualize pain-generating processes, patients with musculoskeletal injuries were investigated and followed-up with [11C]-D-deprenyl PET/CT. In the study of eight patients with ankle sprain, the molecular aspects of inflammation and tissue injury could be visualized, objectively quantified and followed over time with [11C]-D-deprenyl PET/CT. The pain coexisted with increased [11C]-D-deprenyl uptake. In the study of 16 whiplash patients, an altered [11C]-D-deprenyl uptake in the cervical bone structures and facet joints was associated with subjective pain levels and self-rated disability.

    To further evaluate D-Deprenyl’s usefulness as a marker of inflammation, three PET tracers were compared in an animal PET/CT study. Preliminary findings showed that [11C]-D-deprenyl had an almost identical uptake pattern when compared with [11C]-L-deprenyl. The two deprenyl enantiomers showed no signs of specific binding or trapping and therefore may not be useful to study further in models of inflammatory pain, surgical pain, or both.

    This thesis demonstrates that D-deprenyl visualizes painful inflammation in musculoskeletal injuries and that the probable underlying mechanism of [11C]-D-deprenyl uptake is binding to MAO.

  • 2.
    Abbasinejad Enger, Shirin
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Dosimetry Studies of Different Radiotherapy Applications using Monte Carlo Radiation Transport Calculations2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Developing radiation delivery systems for optimisation of absorbed dose to the target without normal tissue toxicity requires advanced calculations for transport of radiation. In this thesis absorbed dose and fluence in different radiotherapy applications were calculated by using Monte Carlo (MC) simulations.

    In paper I-III external neutron activation of gadolinium (Gd) for intravascular brachytherapy (GdNCB) and tumour therapy (GdNCT) was investigated. MC codes MCNP and GEANT4 were compared. MCNP was chosen for neutron capture reaction calculations. Gd neutron capture reaction includes both very short range (Auger electrons) and long range (IC electrons and gamma) products. In GdNCB the high-energetic gamma gives an almost flat absorbed dose delivery pattern, up to 4 mm around the stent. Dose distribution at the edges and inside the stent may prevent stent edge and in-stent restenosis. For GdNCT the absorbed dose from prompt gamma will dominate over the dose from IC and Auger electrons in an in vivo situation. The absorbed dose from IC electrons will enhance the total absorbed dose in the tumours and contribute to the cell killing.

    In paper IV a model for calculation of inter-cluster cross-fire radiation dose from β-emitting radionuclides in a breast cancer model was developed. GEANT4 was used for obtaining absorbed dose. The dose internally in cells binding the isotope (self-dose) increased with decreasing β-energy except for the radionuclides with substantial amounts of conversion electrons and Auger electrons. An effective therapy approach may be a combination of radionuclides where the high self-dose from nuclides with low β-energy should be combined with the inter-cell cluster cross-fire dose from high energy β-particles.

    In paper V MC simulations using correlated sampling together with importance sampling were used to calculate spectra perturbations in detector volumes caused by the detector silicon chip and its encapsulation. Penelope and EGSnrc were used and yielded similar results. The low energy part of the electron spectrum increased but to a less extent if the silicon detector was encapsulated in low z-materials.

  • 3.
    Abbott, Rebecca
    et al.
    Northwestern Univ, IL 60611 USA.
    Peolsson, Anneli
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences.
    West, Janne
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Elliott, James M.
    Northwestern Univ, IL 60611 USA; Univ Queensland, Australia; Zurich Univ Appl Sci, Switzerland.
    Åslund, Ulrika
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences.
    Karlsson, Anette
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Dahlqvist Leinhard, Olof
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    The qualitative grading of muscle fat infiltration in whiplash using fat and water magnetic resonance imaging2018In: The spine journal, ISSN 1529-9430, E-ISSN 1878-1632, Vol. 18, no 5, p. 717-725Article in journal (Refereed)
    Abstract [en]

    BACKGROUND CONTEXT: The development of muscle fat infiltration (MFI) in the neck muscles is associated with poor functional recovery following whiplash injury. Custom software and time-consuming manual segmentation of magnetic resonance imaging (MRI) is required for quantitative analysis and presents as a barrier for clinical translation. PURPOSE: The purpose of this work was to establish a qualitative MRI measure for MFI and evaluate its ability to differentiate between individuals with severe whiplash-associated disorder (WAD), mild or moderate WAD, and healthy controls. STUDY DESIGN/SETTING: This is a cross-sectional study. PATIENT SAMPLE: Thirty-one subjects with WAD and 31 age-and sex-matched controls were recruited from an ongoing randomized controlled trial. OUTCOME MEASURES: The cervical multifidus was visually identified and segmented into eighths in the axial fat/water images (C4-C7). Muscle fat infiltration was assessed on a visual scale: 0 for no or marginal MFI, 1 for light MFI, and 2 for distinct MFI. The participants with WAD were divided in two groups: mild or moderate and severe based on Neck Disability Index % scores. METHODS: The mean regional MFI was compared between the healthy controls and each of the WAD groups using the Mann-Whitney U test. Receiver operator characteristic (ROC) analyses were carried out to evaluate the validity of the qualitative method. RESULTS: Twenty (65%) patients had mild or moderate disability and 11 (35%) were considered severe. Inter- and intra-rater reliability was excellent when grading was averaged by level or when frequency of grade II was considered. Statistically significant differences (pamp;lt;.05) in regional MFI were particularly notable between the severe WAD group and healthy controls. The ROC curve, based on detection of distinct MFI, showed an area-under-the curve of 0.768 (95% confidence interval 0.59-0.94) for discrimination of WAD participants. CONCLUSIONS: These preliminary results suggest a qualitative MRI measure for MFI is reliable and valid, and may prove useful toward the classification of WAD in radiology practice. (C) 2017 Elsevier Inc. All rights reserved.

  • 4.
    Abdsaleh, Shahin
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Core Biopsy of Breast and Axillary Lesions: Technical and Clinical Aspects2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aims of this work were to image and analyze the needle behavior at automated core biopsy, to investigate the clinical utility of an alternative core biopsy technique using a semiautomated gun in breast and axillary lesions, and also to compare core biopsy with surgical specimens in malignant breast lesions regarding histologic features and hormone receptor expression.

    In two experimental studies, using butter and silicon phantoms, respectively, the needle pass was imaged and its dynamic behavior studied. It was shown that the needle took a curved course in phantoms. It deviated to the same side as where the tip lay, and the degree of the curvature increased with increasing hardness of the phantoms. Our experimental methods can be applied for imaging of needle behavior and thereby improvement of needle configuration.

    In two clinical studies, a semiautomated gun was used for large needle core biopsy of breast and axillary lesions in two series of 145 and 21 patients, respectively. The sensitivity of the method for diagnosis of malignancy was 87% (108/124), and in 37% (31/83) of cases the full length of the needle notch was filled with specimen. No injury to the neurovascular structures of the axillary area was observed. It was concluded that the semiautomated gun can be used as an alternative to the automated gun when the size and location of the lesion render use of the automatic device uncertain or dangerous, e.g., in small breast lesions or lesions located in the axilla.

    In a series of 129 cases of breast cancer, comparison of core biopsy and surgical specimens showed that core biopsy provided enough information on the histologic type and grade of the lesions. Also, there was moderate to high concordance between the two methods for assessment of progesterone receptors and estrogen receptors (Spearman`s kappa 0.67 and 0.89, respectively).

  • 5.
    Abdulla, Suzanne
    Örebro University, School of Health and Medical Sciences.
    Stråldos och bildkvalitet vid konventionell frontalbild av ländryggen med och utan kompression2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 6.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lannsjö, Marianne
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Rehabilitation Medicine.
    Howells, Tim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    MRI analysis of diffuse axonal injury - Hemorrhagic lesions in the mesencephalon idicate poor long-term outcome2016In: MRI analysis of diffuse axonal injury - Hemorrhagic lesions in the mesencephalon idicate poor long-term outcome, Springer, 2016, Vol. 7, Suppl. 1, article id B-0814Conference paper (Refereed)
    Abstract [en]

    Purpose: Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. Three MRI techniques were compared in demonstrating acute brain lesions.  Relationship of the anatomical distribution of the lesions in combination with clinical prognostic factors to outcome after 6 months was evaluated.  

    Methods and Materials: Thirty patients, aged 16-60 years (mean 31.2 years) with severe DAI (Glasgow Motor Score = GMS < 6) were examined with MRI at 1.5T within one week after the injury. A diffusion-weighted (DW) sequence (SE-EPI, b value 1000 s/mm2), a T2*-weighted gradient echo (T2*GRE) sequence and a susceptibility-weighted (SWI) sequence were evaluated by two independent reviewers with short and long neuroradiological experiences. Clinical outcome was assessed with Extended Glasgow Outcome Score (GOSE) after ≥ 6 months.

    Results: Interreviewer agreement for DAI classification was very good (ҡ 0.82 – 0.91) with all three sequences. SWI visualized more lesions than the T2*GRE or DW sequence.  In univariate analysis, number of DW lesions in the deep gray matter area including the internal capsules, number of SWI lesions in the mesencephalon, age, and GMS at admission and discharge correlated significantly with poor outcome.  Multivariate analysis only revealed an independent relation with poor outcome for age (p = 0.011) and lesions in the mesencephalic region including crura cerebri, substantia nigra and tegmentum on SWI (p = 0.032).

    Conclusion: SWI is the most sensitive technique to visualize lesions in DAI. Age over 30 years and hemorrhagic mesencephalic lesions anterior to the tectum are indicators of poor long-term outcome in DAI.

  • 7.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Howells, Tim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures.2018In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, p. 1-8Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI. METHODS Fifty-two patients with severe TBI (median age 24 years, range 9-61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression. RESULTS All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%-13%, p = 0.004) and young age (-0.2% of GMT with ICP > 20 mm Hg, 95% CI -0.07% to -0.3%, p = 0.002) were associated with increased ICP. CONCLUSIONS Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.

  • 8.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lönnemark, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Brekkan, Einar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Dahlman, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wernroth, Lisa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular epidemiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Predictive factors for complete renal tumor ablation using RFA2016In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, no 7, p. 886-893Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Radiofrequency ablation (RFA) can be used to treat renal masses in patients where surgery is preferably avoided. As tumor size and location can affect ablation results, procedural planning needs to identify these factors to limit treatment to a single session and increase ablation success.

    PURPOSE: To identify factors that may affect the primary efficacy of complete renal tumor ablation with radiofrequency after a single session.

    MATERIAL AND METHODS: Percutaneous RFA (using an impedance based system) was performed using computed tomography (CT) guidance. Fifty-two renal tumors (in 44 patients) were retrospectively studied (median follow-up, 7 months). Data collection included patient demographics, tumor data (modified Renal Nephrometry Score, histopathological diagnosis), RFA treatment data (electrode placement), and follow-up results (tumor relapse). Data were analyzed through generalized estimating equations.

    RESULTS: Primary efficacy rate was 83%. Predictors for complete ablation were optimal electrode placement (P = 0.002, OR = 16.67) and increasing distance to the collecting system (P = 0.02, OR = 1.18). Tumor size was not a predictor for complete ablation (median size, 24 mm; P = 0.069, OR = 0.47), but all tumors ≤2 cm were completely ablated. All papillary tumors and oncocytomas were completely ablated in a single session; the most common incompletely ablated tumor type was clear cell carcinoma (6 of 9).

    CONCLUSION: Optimal electrode placement and a long distance from the collecting system are associated with an increased primary efficacy of renal tumor RFA. These variables need to be considered to increase primary ablation success. Further studies are needed to evaluate the effect of RFA on histopathologically different renal tumors.

  • 9.
    Adamczuk, Katarzyna
    et al.
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Schaeverbeke, Jolien
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Nelissen, Natalie
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Univ Oxford, Dept Psychiat, Oxford OX3 7JX, England..
    Neyens, Veerle
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Vandenbulcke, Mathieu
    Univ Hosp Leuven, Dept Old Age Psychiat, B-3000 Leuven, Belgium..
    Goffin, Karolien
    Katholieke Univ Leuven, Nucl Med & Mol Imaging Dept, B-3000 Leuven, Belgium.;Univ Hosp Leuven, B-3000 Leuven, Belgium..
    Lilja, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. GE Healthcare, S-75323 Uppsala, Sweden..
    Hilven, Kelly
    Katholieke Univ Leuven, Lab Neuroimmunol, B-3000 Leuven, Belgium..
    Dupont, Patrick
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Van Laere, Koen
    Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Nucl Med & Mol Imaging Dept, B-3000 Leuven, Belgium.;Univ Hosp Leuven, B-3000 Leuven, Belgium..
    Vandenberghe, Rik
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium.;Univ Hosp Leuven, Dept Neurol, B-3000 Leuven, Belgium..
    Amyloid imaging in cognitively normal older adults: comparison between F-18-flutemetamol and C-11-Pittsburgh compound B2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, no 1, p. 142-151Article in journal (Refereed)
    Abstract [en]

    Purpose Preclinical, or asymptomatic, Alzheimer's disease (AD) refers to the presence of positive AD biomarkers in the absence of cognitive deficits. This research concept is being applied to define target populations for clinical drug development. In a prospective community-recruited cohort of cognitively intact older adults, we compared two amyloid imaging markers within subjects: F-18-flutemetamol and C-11-Pittsburgh compound B (PIB). Methods In 32 community-recruited cognitively intact older adults aged between 65 and 80 years, we determined the concordance between binary classification based on F-18-flutemetamol versus C-11-PIB according to semiquantitative assessment (standardized uptake value ratio in composite cortical volume, SUVRcomp) and, alternatively, according to visual reads. We also determined the correlation between F-18-flutemetamol and C-11-PIB SUVR and evaluated how this was affected by the reference region chosen (cerebellar grey matter versus pons) and the use of partial volume correction (PVC) in this population. Results Binary classification based on semiquantitative assessment was concordant between F-18-flutemetamol and C-11-PIB in 94 % of cases. Concordance of blinded binary visual reads between tracers was 84 %. The Spearman correlation between F-18-flutemetamol and C-11-PIB SUVRcomp with cerebellar grey matter as reference region was 0.84, with a slope of 0.98. Correlations in neocortical regions were significantly lower with the pons as reference region. PVC improved the correlation in striatum and medial temporal cortex. Conclusion For the definition of preclinical AD based on F-18-flutemetamol, concordance with C-11-PIB was highest using semiquantitative assessment with cerebellar grey matter as reference region.

  • 10.
    Adams, Christopher
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Kjeldsen, Frank
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics.
    Patriksson, Alexandra
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    van Der Spoel, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Gräslund, Astrid
    Papadopolous, Evangelos
    Zubarev, Roman
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Probing Solution-Phase and Gas-Phase Structures of Trp-cage Cations by Chiral Substitution and Spectroscopic Techniques2006In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 253, no 3, p. 263-273Article in journal (Refereed)
    Abstract [en]

    The relevance of gas-phase protein structure to its solution structure is of the utmost importance in studying biomolecules by mass spectrometry. D-Amino acid substitutions within a minimal protein. Trp-cage. were used to correlate solution-phase properties as measured by circular dichroism with solution/gas-phase conformational features of protein cations probed via charge state distribution (CSD) in electrospray ionization. and gas-phase features revealed by tandem mass spectrometry (MS/MS). The gas-phase features were additionally supported by force-field molecular dynamics simulations. CD data showed that almost any single-residue D-substitution destroys the most prominent CD feature of the "native" all-L isomer, alpha-helicity. CSD was able to qualitatively assess the degree of compactness of solution-phase molecular structures. CSD results were consistent with the all-L form being the most compact in solution among all studied stereoisomers except for the D-Asn(1) isomer. D-substitutions of the aromatic Y(3), W(6) and Q(5) residues generated the largest deviations in CSD data among single amino acid substitutions. consistent with the critical role of these residues in Trp-cage stability. Electron capture dissociation of the stereoisomer dications gave an indication that some gas-phase structural features of Trp-cage are similar to those in solution. This result is supported by MDS data oil five of the studied stereoisomer dications in the gas-phase. The MDS-derived minimum-energy structures possessed more extensive hydrogen bonding than the solution-phase structure of the native form, deviating from the latter by 3-4 angstrom and were not 'inside-out' compared to native structures. MDS data could be correlated with CD data and even with ECD results. which aided in providing a long-range structural constraint for MDS. The overall conclusion is the general resemblance, despite the difference on the detailed level, of the preferred structures in both phases for the mini protein Trp-cage.

  • 11. Adams, D.
    et al.
    Coelho, T.
    Conceicao, E.
    Waddington-Cruz, M.
    Schmidt, H.
    Buades, J.
    Campistol, J. M.
    Pouget, J.
    Berk, J. L.
    Polydefkis, M.
    Ziyadeh, N.
    Partisano, A. M.
    Chen, J.
    Gollob, J.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    PHASE 2 OPEN-LABEL EXTENSION (OLE) STUDY OF PATISIRAN, AN INVESTIGATIONAL RNA INTERFERENCE (RNAI) THERAPEUTIC FOR THE TREATMENT OF HEREDITARY ATTR AMYLOIDOSIS WITH POLYNEUROPATHY2017In: Value in Health, ISSN 1098-3015, E-ISSN 1524-4733, Vol. 20, no 5, p. A211-A212Article in journal (Other academic)
  • 12.
    Adamus-Gorka, Magdalena
    et al.
    Stockholm University, Faculty of Science, Medical Radiation Physics (together with KI).
    Mavroidis, Panayiotis
    Stockholm University, Faculty of Science, Medical Radiation Physics (together with KI).
    Brahme, Anders
    Stockholm University, Faculty of Science, Medical Radiation Physics (together with KI).
    Lind, Bengt K
    Stockholm University, Faculty of Science, Medical Radiation Physics (together with KI).
    An “Effective functional subunit size” model for the dose response of rat spinal cord paralysis2007In: 13th International Congress of Radiation Research, San Fransisco, USA, July 8-12, 2007, 2007Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    Background: Radiobiological models for normal tissue complication probability (NTCP) are more and more commonly used in order to estimate the clinical outcome of radiation therapy. A normal tissue complication probability model to be considered a good and reliable one should fulfill the following two requirements: (a) it should predict the sigmoid shape of the dose-response curve as well as possible and (b) it should duly handle the volume effect. In the work from 2005 (IJROBP 61(3):892-900, 2005) P. van Luijk et al. suggest that none of the existing NTCP models is able to describe the volume effects present in the rat spinal cord during irradiation with small proton beams and they indicate the need for developing such new models.

    Methods: We have used the experimental data from H. Bijl et al. (IJROBP 52(1):205-211, 2002) to try explaining the change in the fifty percent effective dose (ED50) for different field sizes. We initiated this study to evaluate whether the induction of white matter necrosis in rat spinal cord after irradiation with small proton beams could be explained independent of used NTCP model. We therefore introduced a new concept of effective FSU dose, where a convolution of the original dose distribution with a function describing the effective size of a single FSU results in the average doses in a functional subunit. Such procedure allows determining the ED50 in an FSU of a certain size, within the irradiation field. We have also looked at non uniform dose distributions to see whether using a similar method we can explain the so called “bath and shower experiments” (IJROBP 57(1): 274-281, 2003).

    Results: Using the least square method to compare the effective doses for different sizes of functional subunits with the experimental data we observe the best fit for about 8 mm length. It seems that this length could be understood as an effective size of functional subunits in rat spinal cord, explaining what is otherwise interpreted as a volume effect. For the non uniform dose distributions an effective FSU length of 5 mm gives the optimal fit with the Probit dose-response model.

    Conclusions: The concept of an effective FSU length seems to explain at least part of the effects seen when small portions of the rat spinal cord are irradiated. The most likely FSU length for the shower and bath experiments is 5 mm according to these calculations.

  • 13.
    Adjeiwaah, Mary
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Quality assurance for magnetic resonance imaging (MRI) in radiotherapy2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Magnetic resonance imaging (MRI) utilizes the magnetic properties of tissues to generate image-forming signals. MRI has exquisite soft-tissue contrast and since tumors are mainly soft-tissues, it offers improved delineation of the target volume and nearby organs at risk. The proposed Magnetic Resonance-only Radiotherapy (MR-only RT) work flow allows for the use of MRI as the sole imaging modality in the radiotherapy (RT) treatment planning of cancer. There are, however, issues with geometric distortions inherent with MR image acquisition processes. These distortions result from imperfections in the main magnetic field, nonlinear gradients, as well as field disturbances introduced by the imaged object. In this thesis, we quantified the effect of system related and patient-induced susceptibility geometric distortions on dose distributions for prostate as well as head and neck cancers. Methods to mitigate these distortions were also studied.

    In Study I, mean worst system related residual distortions of 3.19, 2.52 and 2.08 mm at bandwidths (BW) of 122, 244 and 488 Hz/pixel up to a radial distance of 25 cm from a 3T PET/MR scanner was measured with a large field of view (FoV) phantom. Subsequently, we estimated maximum shifts of 5.8, 2.9 and 1.5 mm due to patient-induced susceptibility distortions. VMAT-optimized treatment plans initially performed on distorted CT (dCT) images and recalculated on real CT datasets resulted in a dose difference of less than 0.5%.

     The magnetic susceptibility differences at tissue-metallic,-air and -bone interfaces result in local B0 magnetic field inhomogeneities. The distortion shifts caused by these field inhomogeneities can be reduced by shimming.  Study II aimed to investigate the use of shimming to improve the homogeneity of local  B0 magnetic field which will be beneficial for radiotherapy applications. A shimming simulation based on spherical harmonics modeling was developed. The spinal cord, an organ at risk is surrounded by bone and in close proximity to the lungs may have high susceptibility differences. In this region, mean pixel shifts caused by local B0 field inhomogeneities were reduced from 3.47±1.22 mm to 1.35±0.44 mm and 0.99±0.30 mm using first and second order shimming respectively. This was for a bandwidth of 122 Hz/pixel and an in-plane voxel size of 1×1 mm2.  Also examined in Study II as in Study I was the dosimetric effect of geometric distortions on 21 Head and Neck cancer treatment plans. The dose difference in D50 at the PTV between distorted CT and real CT plans was less than 1.0%.

    In conclusion, the effect of MR geometric distortions on dose plans was small. Generally, we found patient-induced susceptibility distortions were larger compared with residual system distortions at all delineated structures except the external contour. This information will be relevant when setting margins for treatment volumes and organs at risk.  

    The current practice of characterizing MR geometric distortions utilizing spatial accuracy phantoms alone may not be enough for an MR-only radiotherapy workflow. Therefore, measures to mitigate patient-induced susceptibility effects in clinical practice such as patient-specific correction algorithms are needed to complement existing distortion reduction methods such as high acquisition bandwidth and shimming.

  • 14.
    Adjeiwaah, Mary
    et al.
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Bylund, Mikael
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Lundman, Josef A.
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Karlsson, Camilla Thellenberg
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Jonsson, Joakim H.
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Nyholm, Tufve
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden.
    Quantifying the Effect of 3T Magnetic Resonance Imaging Residual System Distortions and Patient-Induced Susceptibility Distortions on Radiation Therapy Treatment Planning for Prostate Cancer2018In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 100, no 2, p. 317-324Article in journal (Refereed)
    Abstract [en]

    Purpose: To investigate the effect of magnetic resonance system-and patient-induced susceptibility distortions from a 3T scanner on dose distributions for prostate cancers.

    Methods and Materials: Combined displacement fields from the residual system and patient-induced susceptibility distortions were used to distort 17 prostate patient CT images. VMAT dose plans were initially optimized on distorted CT images and the plan parameters transferred to the original patient CT images to calculate a new dose distribution.

    Results: Maximum residual mean distortions of 3.19 mm at a radial distance of 25 cm and maximum mean patient-induced susceptibility shifts of 5.8 mm were found using the lowest bandwidth of 122 Hz per pixel. There was a dose difference of <0.5% between distorted and undistorted treatment plans. The 90% confidence intervals of the mean difference between the dCT and CT treatment plans were all within an equivalence interval of (-0.5, 0.5) for all investigated plan quality measures.

    Conclusions: Patient-induced susceptibility distortions at high field strengths in closed bore magnetic resonance scanners are larger than residual system distortions after using vendor-supplied 3-dimensional correction for the delineated regions studied. However, errors in dose due to disturbed patient outline and shifts caused by patient-induced susceptibility effects are below 0.5%.

  • 15.
    Adjeiwaah, Mary
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Bylund, Mikael
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Lundman, Josef A.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Thellenberg Karlsson, Camilla
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Jonsson, Joakim H.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Medical Radiation Physics, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
    Quantifying the effect of 3T MRI residual system and patient-induced susceptibility distortions on radiotherapy treatment planning for prostate cancer2018In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 100, no 2, p. 317-324Article in journal (Refereed)
    Abstract [en]

    Purpose: To investigate the effect of magnetic resonance system- and patient-induced susceptibility distortions from a 3T scanner on dose distributions for prostate cancers.

    Methods and Materials: Combined displacement fields from the residual system and patient-induced susceptibility distortions were used to distort 17 prostate patient CT images. VMAT dose plans were initially optimized on distorted CT images and the plan parameters transferred to the original patient CT images to calculate a new dose distribution.

    Results: Maximum residual mean distortions of 3.19 mm at a radial distance of 25 cm and maximum mean patient-induced susceptibility shifts of 5.8 mm were found using the lowest bandwidth of 122 Hz per pixel. There was a dose difference of <0.5% between distorted and undistorted treatment plans. The 90% confidence intervals of the mean difference between the dCT and CT treatment plans were all within an equivalence interval of (−0.5, 0.5) for all investigated plan quality measures.

    Conclusions: Patient-induced susceptibility distortions at high field strengths in closed bore magnetic resonance scanners are larger than residual system distortions after using vendor-supplied 3-dimensional correction for the delineated regions studied. However, errors in dose due to disturbed patient outline and shifts caused by patient-induced susceptibility effects are below 0.5%.

  • 16.
    Adolfsson, Emelie
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    Lithium formate EPR dosimetry for accurate measurements of absorbed dose in radiotherapy2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Lithium formate has shown to be a material with properties suitable for electron paramagnetic resonance (EPR) dosimetry, among them up to 7 times higher sensitivity compared to alanine, which is a well-established EPR detector material for dose determinations in radiotherapy.

    The aim of this thesis was to further investigate the properties of lithium formate and develop the dosimetry system towards applications in radiotherapy. The intrinsic efficiency for energies of relevance to brachytherapy and the signal stability were investigated. The dosimetry system was expanded to include a smaller dosimeter model, suitable for measurements in dose gradient regions. An individual sensitivity correction method was applied to the smaller dosimeters to be able to perform dose determinations with the same precision as for the larger ones. EPR dosimetry in general is time consuming and effort was spent to optimize the signal readout procedure regarding measurement time and measurement precision.

    The system was applied in two clinical applications chosen for their high demands on the dosimetry system: 1) a dosimetry audit for external photon beam therapy and 2) dose verification measurements around a low energy HDR brachytherapy source.

    The conclusions drawn from this thesis were: dose determinations can be performed with a standard uncertainty of 1.8-2.5% using both the original size dosimeters and the new developed smaller ones. The dosimetry system is robust and useful for applications when high measurement precision and accuracy is prioritized. It is a good candidate for dosimetry audits, both in external beam therapy and brachytherapy.

  • 17.
    Adolfsson, Emelie
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    Carlsson Tedgren, Åsa
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics.
    Alm Carlsson, Gudrun
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics.
    Gustafsson, Håkan
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Biomedical Engineering.
    Lund, Eva
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    Optimisation of an EPR dosimetry system for robust and high precision dosimetry2014In: Radiation Measurements, ISSN 1350-4487, E-ISSN 1879-0925, Vol. 70, p. 21-28Article in journal (Refereed)
    Abstract [en]

    Clinical applications of electron paramagnetic resonance (EPR) dosimetry systems demand high accuracy causing time consuming analysis. The need for high spatial resolution dose measurements in regions with steep dose gradients demands small sized dosimeters. An optimization of the analysis was therefore needed to limit the time consumption. The aim of this work was to introduce a new smaller lithium formate dosimeter model (diameter reduced from standard diameter 4.5 mm to 3 mm and height from 4.8 mm to 3 mm). To compensate for reduced homogeneity in a batch of the smaller dosimeters, a method for individual sensitivity correction suitable for EPR dosimetry was tested. Sensitivity and repeatability was also tested for a standard EPR resonator and a super high Q (SHQE) one. The aim was also to optimize the performance of the dosimetry system for better efficiency regarding measurement time and precision. A systematic investigation of the relationship between measurement uncertainty and number of readouts per dosimeter was performed. The conclusions drawn from this work were that it is possible to decrease the dosimeter size with maintained measurement precision by using the SHQE resonator and introducing individual calibration factors for dosimeter batches. It was also shown that it is possible reduce the number of readouts per dosimeter without significantly decreasing the accuracy in measurements.

  • 18.
    Adolfsson, Emelie
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    Gustafsson, Håkan
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Biomedical Engineering.
    Lund, Eva
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    Alm Carlsson, Gudrun
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics.
    Olsson, Sara
    Medical Physics and Technology, Växjö Central Hospital, Växjö, Sweden.
    Carlsson Tedgren, Åsa
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics.
    A system for remote dosimetry audit of 3D-CRT, IMRT and VMAT based on lithium formate dosimetry2014In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 113, no 2, p. 279-282Article in journal (Refereed)
    Abstract [en]

    The aim of this work was to develop and test a remote end-to-end audit system using lithium formate EPR dosimeters. Four clinics were included in a pilot study, absorbed doses determined in the PTV agreed with TPS calculated doses within ±5% for 3D-CRT and ±7% (k=1) for IMRT/VMAT dose plans.

  • 19.
    Adolfsson, Emelie
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    White, Shane
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Landry, Guillaume
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Lund, Eva
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    Gustafsson, Håkan
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Biomedical Engineering.
    Verhaegen, Frank
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Reniers, Brigitte
    Department of Radiation Oncology (MAASTRO), GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center, The Netherlands.
    Carlsson Tedgren, Åsa
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics.
    Alm Carlsson, Gudrun
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics.
    Measurement of absorbed dose to water around an electronic brachytherapy source: Comparison of two dosimetry systems: lithium formate EPR dosimeters and radiochromic EBT2 film2015In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 60, no 9, p. 3869-3882Article in journal (Refereed)
    Abstract [en]

    Interest in high dose rate (HDR) electronic brachytherapy operating at 50 kV is increasing. For quality assurance it is important to identify dosimetry systems that can measure the absorbed doses in absolute terms which is difficult in this energy region. In this work a comparison is made between two dosimetry systems, EPR lithium formate dosimeters and radiochromic EBT2 film.

    Both types of dosimeters were irradiated simultaneously in a PMMA phantom using the Axxent EBS. Absorbed dose to water was determined at distances of 10 mm, 30 mm and 50 mm from the EBS. Results were traceable to different primary standards as regards to absorbed dose to water (EPR) and air kerma (EBT2). Monte Carlo simulations were used in absolute terms as a third estimate of absorbed dose to water.

    Agreement within the estimated expanded (k = 2) uncertainties (5% (EPR), 7% (EBT2)) was found between the results at 30 mm and 50 mm from the x-ray source. The same result was obtained in 4 repetitions of irradiation, indicating high precision in the measurements with both systems. At all distances, agreement between EPR and Monte Carlo simulations was shown as was also the case for the film measurements at 30mm and 50mm. At 10mm the geometry for the film measurements caused too large uncertainty in measured values depending on the exact position (within sub-mm distances) of the EBS and the 10 mm film results were exculded from comparison.

    This work has demonstrated good performance of the lithium formate EPR dosimetry system in accordance with earlier experiments at higher photon energies (192Ir HDR brachytherapy). It was also highlighted that there might be issues regarding the energy dependence and intrinsic efficiency of the EBT2 film that need to be considered for measurements using low energy sources.

  • 20. Aguilar, Carlos
    et al.
    Edholm, Kaijsa
    Simmons, Andrew
    Cavallin, Lena
    Muller, Susanne
    Skoog, Ingmar
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Axelsson, Rimma
    Wahlund, Lars-Olof
    Westman, Eric
    Automated CT-based segmentation and quantification of total intracranial volume2015In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 25, no 11, p. 3151-3160Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To develop an algorithm to segment and obtain an estimate of total intracranial volume (tICV) from computed tomography (CT) images.

    MATERIALS AND METHODS: Thirty-six CT examinations from 18 patients were included. Ten patients were examined twice the same day and eight patients twice six months apart (these patients also underwent MRI). The algorithm combines morphological operations, intensity thresholding and mixture modelling. The method was validated against manual delineation and its robustness assessed from repeated imaging examinations. Using automated MRI software, the comparability with MRI was investigated. Volumes were compared based on average relative volume differences and their magnitudes; agreement was shown by a Bland-Altman analysis graph.

    RESULTS: We observed good agreement between our algorithm and manual delineation of a trained radiologist: the Pearson's correlation coefficient was r = 0.94, tICVml[manual] = 1.05 × tICVml[automated] - 33.78 (R(2) = 0.88). Bland-Altman analysis showed a bias of 31 mL and a standard deviation of 30 mL over a range of 1265 to 1526 mL.

    CONCLUSIONS: tICV measurements derived from CT using our proposed algorithm have shown to be reliable and consistent compared to manual delineation. However, it appears difficult to directly compare tICV measures between CT and MRI.

    KEY POINTS: • Automated estimation of tICV is in good agreement with manual tracing. • Consistent tICV estimations from repeated measurements demonstrate the robustness of the algorithm. • Automatically segmented volumes seem less variable than those from manual tracing. • Unbiased and automated tlCV estimation is possible from CT.

  • 21.
    Ahlander, Britt-Marie
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Magnetic Resonance Imaging of the Heart: Image quality, measurement accuracy and patient experience2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Non-invasive diagnostic imaging of atherosclerotic coronary artery disease (CAD) is frequently carried out with cardiovascular magnetic resonance imaging (CMR) or myocardial perfusion single photon emission computed tomography (MPS). CMR is the gold standard for the evaluation of scar after myocardial infarction and MPS the clinical gold standard for ischemia. Magnetic Resonance Imaging (MRI) is at times difficult for patients and may induce anxiety while patient experience of MPS is largely unknown.

    Aims: To evaluate image quality in CMR with respect to the sequences employed, the influence of atrial fibrillation, myocardial perfusion and the impact of patient information. Further, to study patient experience in relation to MRI with the goal of improving the care of these patients.

    Method: Four study designs have been used. In paper I, experimental cross-over, paper (II) experimental controlled clinical trial, paper (III) psychometric crosssectional study and paper (IV) prospective intervention study. A total of 475 patients ≥ 18 years with primarily cardiac problems (I-IV) except for those referred for MRI of the spine (III) were included in the four studies.

    Result: In patients (n=20) with atrial fibrillation, a single shot steady state free precession (SS-SSFP) sequence showed significantly better image quality than the standard segmented inversion recovery fast gradient echo (IR-FGRE) sequence (I). In first-pass perfusion imaging the gradient echo-echo planar imaging sequence (GREEPI) (n=30) had lower signal-to-noise and contrast–to-noise ratios than the steady state free precession sequence (SSFP) (n=30) but displayed a higher correlation with the MPS results, evaluated both qualitatively and quantitatively (II). The MRIAnxiety Questionnaire (MRI-AQ) was validated on patients, referred for MRI of either the spine (n=193) or the heart (n=54). The final instrument had 15 items divided in two factors regarding Anxiety and Relaxation. The instrument was found to have satisfactory psychometric properties (III). Patients who prior CMR viewed an information video scored significantly (lower) better in the factor Relaxation, than those who received standard information. Patients who underwent MPS scored lower on both factors, Anxiety and Relaxation. The extra video information had no effect on CMR image quality (IV).

    Conclusion: Single shot imaging in atrial fibrillation produced images with less artefact than a segmented sequence. In first-pass perfusion imaging, the sequence GRE-EPI was superior to SSFP. A questionnaire depicting anxiety during MRI showed that video information prior to imaging helped patients relax but did not result in an improvement in image quality.

  • 22.
    Ahlander, Britt-Marie
    et al.
    Örebro University, School of Health Sciences.
    Engvall, Jan
    Department of Clinical Physiology, Linköping University, Linköping, Sweden; Center of Medical Image Science and Visualization, Linköping University, Linköping, Sweden.
    Maret, Eva
    Department of Clinical Physiology, Karolinska Institute, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    Ericsson, Elisabeth
    Örebro University, School of Health Sciences.
    Positive effect on patient experience of video information given prior to cardiovascular magnetic resonance imaging: A clinical trial2018Conference paper (Refereed)
  • 23.
    Ahlander, Britt-Marie
    et al.
    Department of Radiology, Ryhov County Hosptial, Jönköping, Sweden.
    Engvall, Jan
    Department of Clinical Physiology, Linköping University, Linköping, Sweden; Center of Medical Image Science and Visualization, Linköping University, Linköping, Sweden.
    Maret, Eva
    Department of Clinical Physiology, Karolinska Institutet, stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    Ericsson, Elisabeth
    Örebro University, School of Health Sciences.
    Positive effect on patient experience of video-information given prior to cardiovascular magnetic resonance imaging, a clinical trial2018In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 27, no 5-6, p. 1250-1261Article in journal (Refereed)
    Abstract [en]

    Aims and objectives: To evaluate the effect of video information given before cardiovascular magnetic resonance imaging on patient anxiety and to compare patient experiences of cardiovascular magnetic resonance imaging versus myocardial perfusion scintigraphy. To evaluate whether additional information has an impact on motion artefacts.

    Background: Cardiovascular magnetic resonance imaging and myocardial perfusion scintigraphy are technically advanced methods for the evaluation of heart diseases. Although cardiovascular magnetic resonance imaging is considered to be painless, patients may experience anxiety due to the closed environment.

    Design: A prospective randomised intervention study, not registered.

    Methods: The sample (n = 148) consisted of 97 patients referred for cardiovascular magnetic resonance imaging, randomised to receive either video information in addition to standard text-information (CMR-video/n = 49) or standard text-information alone (CMR-standard/n = 48). A third group undergoing myocardial perfusion scintigraphy (n = 51) was compared with the cardiovascular magnetic resonance imaging-standard group. Anxiety was evaluated before, immediately after the procedure and 1 week later. Five questionnaires were used: Cardiac Anxiety Questionnaire, State-Trait Anxiety Inventory, Hospital Anxiety and Depression scale, MRI Fear Survey Schedule and the MRI-Anxiety Questionnaire. Motion artefacts were evaluated by three observers, blinded to the information given. Data were collected between April 2015–April 2016. The study followed the CONSORT guidelines.

    Result: The CMR-video group scored lower (better) than the cardiovascular magnetic resonance imaging-standard group in the factor Relaxation (p =.039) but not in the factor Anxiety. Anxiety levels were lower during scintigraphic examinations compared to the CMR-standard group (p <.001). No difference was found regarding motion artefacts between CMR-video and CMR-standard.

    Conclusion: Patient ability to relax during cardiovascular magnetic resonance imaging increased by adding video information prior the exam, which is important in relation to perceived quality in nursing. No effect was seen on motion artefacts.

    Relevance to clinical practice: Video information prior to examinations can be an easy and time effective method to help patients cooperate in imaging procedures.

  • 24.
    Ahlander, Britt-Marie
    et al.
    Örebro University, School of Health Sciences.
    Ericsson, Elisabeth
    Örebro University, School of Health Sciences.
    Maret, Eva
    Department of Clinical Physiology, Karolinska Institutet, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    Engvall, Jan
    Department of Clinical Physiology, Linköping University, Linköping, Sweden; Center of Medical Image Science and Visualization, Linköping University, Linköping, Sweden.
    Magnetkameraundersökning av hjärtat2014Conference paper (Other academic)
  • 25.
    Ahlander, Britt-Marie
    et al.
    Örebro University, School of Health Sciences. Röntgenavdelningen, Ryhov, Jönköping.
    Ericsson, Elisabeth
    Örebro University, School of Health Sciences.
    Maret, Eva
    Department of Clinical Physiology, Karolinska Institute, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    Engvall, Jan
    Department of Clinical Physiology, Linköping University Hospital, Linköping, Sweden; Center of Medical Image Science and Visualization, Linköping University, Linköping, Sweden.
    Magnetkameraundersökning av hjärtat: bildkvalitet, mätnoggrannhet och patientupplevelse2017Conference paper (Refereed)
    Abstract [sv]

    Syfte:

    Att utvärdera bildkvaliteten vid magnetkamera undersökning av hjärtat (hjärt-MR) genom val av sekvens vid undersökning av infarktutbredning hos patienter med förmaksflimmer och vid studie av hjärtmuskelns genomblödning, samt eventuell inverkan av given information.

    Att studera patientens upplevelse vid hjärt-MR med målet att kunna förbättre patientupplevelsenoch bildkvaliteten.

    Material och metoder:

    På 20 patienter med förmaksflimmer och genomgången hjärtinfarkt har två viabilitetssekvenser jämförts, en segmenterad (bilden samlas in under flera hjärtslag) och en single shot (bilden samlas in under ett hjärtslag).

    På 60 patienter remitterade för hjärtscintigrafi gjordes även hjärt-MR. Perfusionssekvenser utfördes under Adenosine-stress. Två olika sekvenser användes, SSFP och GRE-EPI. Undersökningarna har utvärderats både visuellt och semi-kvantitativt med hjärtscintigrafi som referensmetod.

    Med resultatet från en studie av Erna Törnqvist et al (2006), har ett skattningsinstrument konstruerats, Magnetic Resonance Imaging - Anxiety Questionnaire (MRI-QA). För validering har 247 patienter remitterade för MR-undersökning av rygg (n=193) och hjärta (n=54) besvarat frågorna.

    På två grupper av patienter remitterade för hjärt-MR har informationens betydelse utvärderats. En grupp erhöll video information (n=49) och en standard information (n=48). Likaså utvärderades informationens betydelse för bildkvaliteten.

    Resultat:

    Single shot sekvensen hade bättre bildkvalitet än den segmenterade. Hjärtinfarktens utbredning överensstämde mellan de båda sekvenserna.

    Trots att SSFP sekvensen hade bättre signal brus och kontrast brus förhållande överensstämde GREEPI sekvensen bäst med myokardscintigrafin både vid visuell och vid semi-kvantitativ bedömning.

    MRI-AQ resulterade i 15 påståenden. Det består av två faktorer, en som mäter ångest (12 påståenden) och en som mäter avslappning (tre påståenden). Det har psykometriska förutsättningar att kunna värdera patienters upplevelse av MR-undersökning.

    Patienter som fick utökad information i form av en film var signifikant mer avslappnade under undersökningen än patienter som fick standardinformation. Däremot påverkade inte den utökade informationen bildkvaliteten.

    Konklusion:

    Vid undersökning av infarktstorleken hos patienter med förmaksflimmer hade single shot sekvensen högre bildkvalitet än den segmenterade sekvensen.

    Vid bedömning av ischemi överensstämde hjärt-MR bättre med myokardscintigrafin om GRE-EPI sekvensen användes jämfört med SSFP sekvensen. Detta gällde både vid visuell och semi-kvantitativ bedömning.

    MRI-AQ bedöms som ett tillförlitligt instrument att använda för att utvärdera effekter av intervention vid MR-undersökning.

    Utökad information med video gör patienten mer avslappnad i undersökningssituationen men har ingen påverkan på bildkvaliteten.

  • 26.
    Ahlander, Britt-Marie
    et al.
    Örebro University, School of Health Sciences. Jönköping County Hospital, Jönköping, Sweden.
    Ericsson, Elisabeth
    Örebro University, School of Health Sciences.
    Maret, Eva
    Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden.
    Engvall, Jan
    Linköping University, Linköping, Sweden.
    Video information prior to cardiovascular magnetic resonance imaging improves patient experience which still remains more challenging than in myocardial perfusion scintigraphy2017Conference paper (Refereed)
    Abstract [en]

    Background: Cardiovascular magnetic resonance imaging (CMR) and myocardial perfusion scintigraphy (MPS) are two technically advanced methods for imaging cardiac diseases. Although CMR is considered to be painless, considerable patient cooperation is necessary during scanning. Some patients may experience anxiety because of the closed environment of the procedure.

    The aims of this paper were to evaluate the potential effect on patient anxiety and on motion artefacts by adding a 5 min video sequence to the standard written information given before CMR. Additionally, the patient experience of CMR was compared to that of MPS.

    Methods: The sample (n=146) consisted of 97 patients randomized to receive either video information in addition to standard written information (CMR-video/n=49) or standard written information alone (CMR-standard/n=48). A third group undergoing MPS (n=51) was used to compare CMR-standard and MPS. Anxiety was evaluated before, immediately after the procedure and one week later. Four questionnaires were used: State-Trait-Anxiety Inventory, Hospital-Anxiety and Depression-scale, MRI-Fear-Survey-Schedule and the MRI-Anxiety-Questionnaire (MRI-AQ). Motion artefacts were evaluated by three observers, blinded to the information given. Motion artefacts due to arrhythmia were not considered.

    Results: Measured with MRI-AQ, the CMR-video and the CMR-standard groups did not score significantly different on the factor Anxiety. However, CMR-video scored lower (=better) in the factor Relaxation (p=0.039). Younger patients and women scored a higher level of anxiety in most scales. Anxiety levels (MRI-AQ) were lower during MPS examinations compared to the CMRstandard group (p < 0.001 ). The presence of motion artefacts was similar in the CMR-video compared to the CMR-standard group.

    Conclusions: Patient ability to relax during CMR increased by adding video information prior to the exam. This positive effect on patient experience is important to enable technologists to obtain full patient cooperation. An apparent lack of effect on motion artefact could possibly be due to the addition of compensatory extra scans when a low image quality was recognized by the technologists.

  • 27.
    Ahlander, Britt-Marie
    et al.
    Department of Radiology, Ryhov County Hospital, Jönköping.
    Maret, Eva
    Department of Radiology, Ryhov County Hospital, Jönköping / Department of Clinical Physiology, Karolinska University Hospital, Stockholm.
    Brudin, Lars
    Department of Clinical Physiology, Kalmar County Hospital, Kalmar.
    Starck, Sven-Åke
    Department of Natural Science and Biomedicine, School of Health Sciences, Jönköping University / Department of Oncology, Hospital Physics, Ryhov County Hospital, Jönköping.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
    An echo-planar imaging sequence is superior to a steady-state free precession sequence for visual as well as quantitative assessment of cardiac magnetic resonance stress perfusion2017In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 37, no 1, p. 52-61Article in journal (Refereed)
    Abstract [en]

    Background To assess myocardial perfusion, steady-state free precession cardiac magnetic resonance (SSFP, CMR) was compared with gradient-echo–echo-planar imaging (GRE-EPI) using myocardial perfusion scintigraphy (MPS) as reference. Methods Cardiac magnetic resonance perfusion was recorded in 30 patients with SSFP and in another 30 patients with GRE-EPI. Timing and extent of inflow delay to the myocardium was visually assessed. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated. Myocardial scar was visualized with a phase-sensitive inversion recovery sequence (PSIR). All scar positive segments were considered pathologic. In MPS, stress and rest images were used as in clinical reporting. The CMR contrast wash-in slope was calculated and compared with the stress score from the MPS examination. CMR scar, CMR perfusion and MPS were assessed separately by one expert for each method who was blinded to other aspects of the study. Results Visual assessment of CMR had a sensitivity for the detection of an abnormal MPS at 78% (SSFP) versus 91% (GRE-EPI) and a specificity of 58% (SSFP) versus 84% (GRE-EPI). Kappa statistics for SSFP and MPS was 0·29, for GRE-EPI and MPS 0·72. The ANOVA of CMR perfusion slopes for all segments versus MPS score (four levels based on MPS) had correlation r = 0·64 (SSFP) and r = 0·96 (GRE-EPI). SNR was for normal segments 35·63 ± 11·80 (SSFP) and 17·98 ± 8·31 (GRE-EPI), while CNR was 28·79 ± 10·43 (SSFP) and 13·06 ± 7·61 (GRE-EPI). Conclusion GRE-EPI displayed higher agreement with the MPS results than SSFP despite significantly lower signal intensity, SNR and CNR.

  • 28.
    Ahlander, Britt-Marie
    et al.
    Department of Radiology, Ryhov County Hospital, Jönköping, Sweden.
    Årestedt, Kristofer
    Department of Medical and Health Sciences, Division of Nursing Science, Linköping University, Linköping, Sweden; Center for Collaborative Palliative Care, Linnaeus University, Kalmar, Sweden.
    Engvall, Jan
    Department of Clinical Physiology, Linköping University, Linköping, Sweden; Center of Medical Image Science and Visualization, Linköping University, Linköping, Sweden.
    Maret, Eva
    Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden; Karolinska Institutet, Stockholm, Sweden.
    Ericsson, Elisabeth
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Development and validation of a questionnaire evaluating patient anxiety during Magnetic Resonance Imaging: the Magnetic Resonance Imaging- Anxiety Questionnaire (MRI-AQ)2016In: Journal of Advanced Nursing, ISSN 0309-2402, E-ISSN 1365-2648, Vol. 72, no 6, p. 1368-1380Article in journal (Refereed)
    Abstract [en]

    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.

  • 29.
    Ahle, Margareta
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Radiology in Linköping.
    Necrotising Enterocolitis: epidemiology and imaging2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Necrotising enterocolitis (NEC) is a potentially devastating intestinal inflammation of multifactorial aetiology in premature or otherwise vulnerable neonates. Because of the broad spectrum of presentations, diagnosis and timing of surgical intervention may be challenging, and imaging needs to be an integrated part of management.

    The first four studies included in this thesis used routinely collected, nationwide register data to describe the incidence of NEC in Sweden 1987‒2009, its variation with time, seasonality, space-time clustering, and associations with maternal, gestational, and perinatal factors, and the risk of intestinal failure in the aftermath of the disease.

    Early infant survival increased dramatically during the study period. The incidence rate of NEC was 0.34 per 1,000 live births, rising from 0.26 per 1,000 live births in the first six years of the study period to 0.57 in the last five. The incidence rates in the lowest birth weights were 100‒160 times those of the entire birth cohort. Seasonal variation was found, as well as space-time clustering in association with delivery hospitals but not with maternal residential municipalities.

    Comparing NEC cases with matched controls, some factors, positively associated with NEC, were isoimmunisation, fetal distress, caesarean section, persistent ductus arteriosus, cardiac and gastrointestinal malformations, and chromosomal abnormalities. Negative associations included maternal pre-eclampsia, maternal urinary infection, and premature rupture of the membranes. Intestinal failure occurred in 6% of NEC cases and 0.4% of controls, with the highest incidence towards the end of the study period.

    The last study investigated current practices and perceptions of imaging in the management of NEC, as reported by involved specialists. There was great consensus on most issues. Areas in need of further study seem mainly related to imaging routines, the use of ultrasound, and indications for surgery.

    Developing alongside the progress of neonatal care, NEC is a complex, multifactorial disease, with shifting patterns of predisposing and precipitating causes, and potentially serious long-term complications. The findings of seasonal variation, spacetime clustering, and negative associations with antenatal exposure to infectious agents, fit into the growing understanding of the central role of bacteria and immunological processes in normal maturation of the intestinal canal as well as in the pathogenesis of NEC. Imaging in the management of NEC may be developed through future studies combining multiple diagnostic parameters in relation to clinical outcome.

  • 30.
    Ahle, Margareta
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Radiology in Linköping.
    Rubesova, Erika
    Stanford university, US.
    Ringertz, Hans
    Stanford university, US.
    The significance of radiographic and ultrasonographic findings in the management of necrotising enterocolitis - results from a survey2017Conference paper (Other academic)
    Abstract [en]

    Necrotising Enterocolitis (NEC) remains a potentially devastating emergency in neonates, predominantly the premature. Ever since it was first described in the 60's, imaging has played a great role in definition, staging, and monitoring of the disease. The radiographic image can change before the clinical condition, but typical signs are often transient and may be missing even in severe NEC [1-4]. These circumstances have led to the recommendation of frequent imaging and to the insight that the clinical decisions cannot rely solely on radiological signs [5-7]. Ultrasound (US) as a possibility to enhance sensitivity and diagnostic accuracy was first described in the mid 80's [8, 9] and was included in a diagnostic algorithm suggested by in 1994 [6], but despite great effort to develop and validate the method, its role in the management of NEC has not yet been established [7, 10, 11].

    Meanwhile, in order to improve interobserver agreement and diagnostic accuracy of AR, the radiographic signs of NEC have also been systematized into the DAAS scale [12]. Imaging, as an adjunct to clinical assessment [11], is crucial in the diagnosis and management of NEC. The purpose of this survey was to investigate current views and routines, as described by involved specialists, and identify areas in need of further study and discussion.

  • 31.
    Ahle, Margareta
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Radiology in Linköping.
    Rubesova, Erika
    Stanford university, US.
    Ringertz, Hans
    Stanford university, US.
    The use of imaging in necrotising enterocolitis - results from a survey2017Conference paper (Other academic)
  • 32.
    Ahlgren, Johanna
    Luleå University of Technology, Department of Health Sciences.
    Det korta mötet med barn i vården: En litteraturstudie om upplevelser hos sjuksköterskor2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Inledning: Den största anledningen till att barn kommer i kontakt med sjukvården är på grund av misstänkt fraktur, vilket innebär att röntgensjuksköterskor ofta möter barn i det dagliga arbetet på röntgenavdelningen. Trots det är dessa sällan utbildade i bemötande av barn, eller inom pediatrisk bildtagning. Vuxna som inte är vana vid att hantera barn kan känna viss tveksamhet eller rädsla inför att vårda ett barn. För att kunna förbättra mötet med barn är det viktigt att veta vilka känslor sjukvårdpersonal känner i mötet, och varför. Syfte: att beskriva vilka upplevelser sjukvårdpersonal känner i mötet med barn. Metod: Studien utfördes som en litteraturöversikt med 10 artiklar som granskades med en induktiv kvalitativ innehållsanalys. De 10 artiklarna var av kvalitativ ansats och intervjuade sjukvårdspersonal som bestod av ambulanspersonal, akutsjuksköterskor, allmänsjuksköterskor och radioterapeuter. Resultat: Fyra kategorier; bemötande, hanterbarhet, tiden har betydelse och föräldrar. Dessa beskriver i vilka situationer sjukvårdspersonal upplever både negativa och positiva känslor i mötet med barn. Slutsats: att identifiera vilka känslor som uppstår är grunden för fortsatta studier för att förbättra arbetsmiljön för såväl röntgensjuksköterskor som övrig sjukvårdspersonal. 

  • 33.
    Ahlgren, Sara
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Molecular Radionuclide Imaging Using Site-specifically Labelled Recombinant Affibody Molecules: Preparation and Preclinical Evaluation2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Radionuclide molecular imaging is an emerging multidisciplinary technique that is used in modern medicine to visualise diseases at cellular and molecular levels. This thesis is based on five papers (I-V) and focuses on the development of site-specific radiolabelled recombinant anti-HER2 Affibody molecules and preclinical evaluations in vitro and in vivo of the labelled conjugates. This work is part of a preclinical development of an Affibody molecule-based tracer for molecular imaging of HER2 expressing tumours.

    Papers I and II report the evaluation of the Affibody molecule ZHER2:2395-C, site-specifically labelled with the radiometals 111In (for SPECT) and 57Co (as a surrogate for 55Co, suitable for PET applications) using a thiol reactive DOTA derivative as a chelator. Both conjugates demonstrated very suitable biodistribution properties, enabling high contrast imaging just a few hours after injection.

    Papers III and IV report the development and optimization of a technique for site-specific labelling of ZHER2:2395-C with 99mTc using an N3S chelating peptide sequence. 99mTc-ZHER2:2395-C demonstrated high and specific tumour uptake and rapid clearance of non-bound tracer from the blood, resulting in high tumour-to-non-tumour ratios shortly after injection, enabling high contrast imaging. In addition, in the study described in paper IV, freeze-dried kits previously developed for 99mTc-labelling were optimised, resulting in the development of a kit in which all the reagents and protein needed for labelling of ZHER2:2395-C with 99mTc were contained in a single vial.

    Paper V reports the evaluation of an anti-HER2 Affibody molecule, ABY-025, with a fundamentally re-engineered scaffold. Despite the profound re-engineering, the biodistribution pattern of 111In-ABY-025 was very similar to that of two variants of the parental molecule.

    It seems reasonable to believe that these results will also be applicable to Affibody molecules towards other targets. Hopefully, this work will also be helpful in the development of other small proteinaceous tracers.

  • 34.
    Ahlgren, Ulf
    Umeå University, Faculty of Medicine, Umeå Centre for Molecular Medicine (UCMM).
    Exploring the pancreas with optical projection tomography2012In: Imaging in Medicine, ISSN 1755-5191, Vol. 4, no 1, p. 5-7Article in journal (Refereed)
  • 35.
    Ahlinder, Linnea
    et al.
    Swedish Def Res Agcy, FOI, Cementvagen 20, SE-90182 Umea, Sweden..
    Lindstrom, Susanne Wiklund
    Swedish Def Res Agcy, FOI, Cementvagen 20, SE-90182 Umea, Sweden..
    Lejon, Christian
    Swedish Def Res Agcy, FOI, Cementvagen 20, SE-90182 Umea, Sweden..
    Geladi, Paul
    Swedish Univ Agr Sci, Dept Forest Biomat & Technol, SE-90183 Umea, Sweden..
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Noise Removal with Maintained Spatial Resolution in Raman Images of Cells Exposed to Submicron Polystyrene Particles2016In: NANOMATERIALS, ISSN 2079-4991, Vol. 6, no 5, article id UNSP 83Article in journal (Refereed)
    Abstract [en]

    The biodistribution of 300 nm polystyrene particles in A549 lung epithelial cells has been studied with confocal Raman spectroscopy. This is a label-free method in which particles and cells can be imaged without using dyes or fluorescent labels. The main drawback with Raman imaging is the comparatively low spatial resolution, which is aggravated in heterogeneous systems such as biological samples, which in addition often require long measurement times because of their weak Raman signal. Long measurement times may however induce laser-induced damage. In this study we use a super-resolution algorithm with Tikhonov regularization, intended to improve the image quality without demanding an increased number of collected pixels. Images of cells exposed to polystyrene particles have been acquired with two different step lengths, i.e., the distance between pixels, and compared to each other and to corresponding images treated with the super-resolution algorithm. It is shown that the resolution after application of super-resolution algorithms is not significantly improved compared to the theoretical limit for optical microscopy. However, to reduce noise and artefacts in the hyperspectral Raman images while maintaining the spatial resolution, we show that it is advantageous to use short mapping step lengths and super-resolution algorithms with appropriate regularization. The proposed methodology should be generally applicable for Raman imaging of biological samples and other photo-sensitive samples.

  • 36. Ahlstedt, J.
    et al.
    Orbom, A.
    Akesson, A.
    Frejd, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Strand, S.
    Tran, T.
    Simultaneous dual-radionuclide SPECT-imaging of HER2 expression using 99mTc-Affibody/111In-trastuzumab2014In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 41, no S2, p. S274-S274, article id OP522Article in journal (Other academic)
  • 37.
    Ahlström, Håkan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ekström, Simon
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Sjöholm, Therese
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Strand, Robin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Kullberg, Joel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, E.
    Antaros Med, Molndal, Sweden..
    Hagmar, P.
    Antaros Med, Molndal, Sweden..
    Malmberg, Filip
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Registration-based automated lesion detection and therapy evaluation of tumors in whole body PET-MR images2017In: Annals of Oncology, ISSN 0923-7534, E-ISSN 1569-8041, Vol. 28, no S5, article id 78PArticle in journal (Other academic)
  • 38.
    Ahmad Hossein, Sadegh
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Jämförelse av två radiologiska undersökningsmetoder vid njurstensfrågeställning: En litteraturstudie2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 39.
    Ahmadi, Maryam
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    En jämförelse mellan ultraljudundersökning och mammografi vid bröstdiagnostik: en litteraturstudie2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 40.
    Ahmed, Adan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Bemötande av barn på röntgen2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Barnen är oftast rädda och oroliga då de kommer till en röntgenundersökning på grund av att det är en främmande miljö utrustad med högteknologisk apparatur som är skrämmande för barnet. För att bemöta dessa barn behöver röntgensjuksköterskan ha kunskap och färdigheter om bemötande av barn. Ett bra samspel mellan röntgensjuksköterskan och barnen som bygger på ömsesidig tillit och respekt ger trygghet hos barnet och det kan samarbeta bättre under röntgenundersökningen. På en kort tid, ofta mindre än 5 minuter, måste en röntgensjuksköterska överföra viktig information om undersökningen till barnet. Därför är det viktigt för röntgensjuksköterskan att ha kunskap om gott bemötande av barn.

  • 41.
    Ahnesjö, Anders
    et al.
    Uppsala University, Sweden.
    van Veelen, Bob
    Elekta Brachytherapy, Netherlands.
    Carlsson Tedgren, Åsa
    Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Radiation Physics. Karolinska University Hospital, Sweden.
    Collapsed cone dose calculations for heterogeneous tissues in brachytherapy using primary and scatter separation source data2017In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 139, p. 17-29Article in journal (Refereed)
    Abstract [en]

    Background and Objective: Brachytherapy is a form of radiation therapy using sealed radiation sources inserted within or in the vicinity of the tumor of, e.g., gynecological, prostate or head and neck cancers. Accurate dose calculation is a crucial part of the treatment planning. Several reviews have called for clinical software with model-based algorithms that better take into account the effects of patient individual distribution of tissues, source-channel and shielding attenuation than the commonly employed TG-43 formalism which simply map homogeneous water dose distributions onto the patient. In this paper we give a comprehensive and thorough derivation of such an algorithm based on collapsed cone point-kernel superposition, and describe details of its implementation into a commercial treatment planning system for clinical use. Methods: A brachytherapy version of the collapsed-cone algorithm using analytical raytraces of the primary photon radiation followed by successive scattering dose calculation for once and multiply scattered photons is described in detail, including derivation of the corresponding set of recursive equations for energy transport along cone axes/transport lines and the coupling to clinical source modeling. Specific implementation issues for setting up of the calculation grid, handling of intravoxel gradients and voxels partly containing non patient applicator material are given. Results: Sample runs for two clinical cases are shown, one being a gynecological application with a tungsten-shielded applicator and one a breast implant. These two cases demonstrate the impact of improved dose calculation versus TG-43 formalism. Conclusions: Use of model-based dose calculation algorithms for brachytherapy taking the three-dimensional treatment geometry into account increases the dosimetric accuracy in planning and follow up of treatments. The comprehensive description and derivations provided gives a rigid background for further clinical, educational and research applications. (C) 2016 Elsevier Ireland Ltd. All rights reserved.

  • 42.
    Ahnesjö, Anders
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    van Veelen, Bob
    Elekta Brachytherapy, NL-3905 TH Veenendaal, Netherlands..
    Tedgren, Asa Carlsson
    Linkoping Univ, Fac Hlth Sci, Dept Med & Hlth Sci IMH, Radiat Phys, SE-58185 Linkoping, Sweden.;Karolinska Univ Hosp, Dept Med Phys, Sect Radiotherapy Phys & Engn, SE-17176 Stockholm, Sweden..
    Collapsed cone dose calculations for heterogeneous tissues in brachytherapy using primary and scatter separation source data2017In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 139, p. 17-29Article in journal (Refereed)
    Abstract [en]

    Background and Objective: Brachytherapy is a form of radiation therapy using sealed radiation sources inserted within or in the vicinity of the tumor of, e.g., gynecological, prostate or head and neck cancers. Accurate dose calculation is a crucial part of the treatment planning. Several reviews have called for clinical software with model-based algorithms that better take into account the effects of patient individual distribution of tissues, source-channel and shielding attenuation than the commonly employed TG-43 formalism which simply map homogeneous water dose distributions onto the patient. In this paper we give a comprehensive and thorough derivation of such an algorithm based on collapsed cone point-kernel superposition, and describe details of its implementation into a commercial treatment planning system for clinical use. Methods: A brachytherapy version of the collapsed-cone algorithm using analytical raytraces of the primary photon radiation followed by successive scattering dose calculation for once and multiply scattered photons is described in detail, including derivation of the corresponding set of recursive equations for energy transport along cone axes/transport lines and the coupling to clinical source modeling. Specific implementation issues for setting up of the calculation grid, handling of intravoxel gradients and voxels partly containing non patient applicator material are given. Results: Sample runs for two clinical cases are shown, one being a gynecological application with a tungsten-shielded applicator and one a breast implant. These two cases demonstrate the impact of improved dose calculation versus TG-43 formalism. Conclusions: Use of model-based dose calculation algorithms for brachytherapy taking the three-dimensional treatment geometry into account increases the dosimetric accuracy in planning and follow up of treatments. The comprehensive description and derivations provided gives a rigid background for further clinical, educational and research applications.

  • 43. Ainsbury, E A
    et al.
    Bakhanova, E
    Barquinero, J F
    Brai, M
    Chumak, V
    Correcher, V
    Darroudi, F
    Fattibene, P
    Gruel, G
    Guclu, I
    Horn, S
    Jaworska, A
    Kulka, U
    Lindholm, C
    Lloyd, D
    Longo, A
    Marrale, M
    Monteiro Gil, O
    Oestreicher, U
    Pajic, J
    Rakic, B
    Romm, H
    Trompier, F
    Veronese, I
    Voisin, P
    Vral, A
    Whitehouse, C A
    Wieser, A
    Woda, C
    Wojcik, Andrzej
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Rothkamm, K
    REVIEW OF RETROSPECTIVE DOSIMETRY TECHNIQUES FOR EXTERNAL IONISING RADIATION EXPOSURES.2011In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 147, no 4, p. 573-592Article in journal (Refereed)
    Abstract [en]

    The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements.

  • 44. Ainsbury, Elizabeth A.
    et al.
    Higueras, Manuel
    Puig, Pedro
    Einbeck, Jochen
    Samaga, Daniel
    Francesc Barquinero, Joan
    Barrios, Lleonard
    Brzozowska, Beata
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute. University of Warsaw, Poland.
    Fattibene, Paola
    Gregoire, Eric
    Jaworska, Alicja
    Lloyd, David
    Oestreicher, Ursula
    Romm, Horst
    Rothkamm, Kai
    Roy, Laurence
    Sommer, Sylwester
    Terzoudi, Georgia
    Thierens, Hubert
    Trompier, Francois
    Vral, Anne
    Woda, Clemens
    Uncertainty of fast biological radiation dose assessment for emergency response scenarios2017In: International Journal of Radiation Biology, ISSN 0955-3002, E-ISSN 1362-3095, Vol. 93, no 1, p. 127-135Article in journal (Refereed)
    Abstract [en]

    Purpose: Reliable dose estimation is an important factor in appropriate dosimetric triage categorization of exposed individuals to support radiation emergency response. Materials and methods: Following work done under the EU FP7 MULTIBIODOSE and RENEB projects, formal methods for defining uncertainties on biological dose estimates are compared using simulated and real data from recent exercises. Results: The results demonstrate that a Bayesian method of uncertainty assessment is the most appropriate, even in the absence of detailed prior information. The relative accuracy and relevance of techniques for calculating uncertainty and combining assay results to produce single dose and uncertainty estimates is further discussed. Conclusions: Finally, it is demonstrated that whatever uncertainty estimation method is employed, ignoring the uncertainty on fast dose assessments can have an important impact on rapid biodosimetric categorization.

  • 45. Ainsbury, Elizabeth
    et al.
    Badie, Christophe
    Barnard, Stephen
    Manning, Grainne
    Moquet, Jayne
    Abend, Michael
    Antunes, Ana Catarina
    Barrios, Lleonard
    Bassinet, Celine
    Beinke, Christina
    Bortolin, Emanuela
    Bossin, Lily
    Bricknell, Clare
    Brzoska, Kamil
    Buraczewska, Iwona
    Huertas Castano, Carlos
    Cemusova, Zina
    Christiansson, Maria
    Mateos Cordero, Santiago
    Coster, Guillaume
    Della Monac, Sara
    Desangles, Francois
    Discher, Michael
    Dominguez, Inmaculada
    Doucha-Senf, Sven
    Eakins, Jon
    Fattibene, Paola
    Filippi, Silvia
    Frenzel, Monika
    Georgieva, Dimka
    Gregoire, Eric
    Guogyte, Kamile
    Hadjidekova, Valeria
    Hadjiiska, Ljubomira
    Hristova, Rositsa
    Karakosta, Maria
    Kis, Eniko
    Kriehuber, Ralf
    Lee, Jungil
    Lloyd, David
    Lumniczky, Katalin
    Lyng, Fiona
    Macaeva, Ellina
    Majewski, Matthaeus
    Vanda Martins, S.
    McKeever, Stephen W. S.
    Meade, Aidan
    Medipally, Dinesh
    Meschini, Roberta
    M'kacher, Radhia
    Gil, Octavia Monteiro
    Montero, Alegria
    Moreno, Mercedes
    Noditi, Mihaela
    Oestreicher, Ursula
    Oskamp, Dominik
    Palitti, Fabrizio
    Palma, Valentina
    Pantelias, Gabriel
    Pateux, Jerome
    Patrono, Clarice
    Pepe, Gaetano
    Port, Matthias
    Jesus Prieto, Maria
    Quattrini, Maria Cristina
    Quintens, Roel
    Ricoul, Michelle
    Roy, Laurence
    Sabatier, Laure
    Sebastia, Natividad
    Sholom, Sergey
    Sommer, Sylwester
    Staynova, Albena
    Strunz, Sonja
    Terzoudi, Georgia
    Testa, Antonella
    Trompier, Francois
    Valente, Marco
    Van Hoey, Olivier
    Veronese, Ivan
    Wojcik, Andrzej
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Woda, Clemens
    Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans - joint RENEB and EURADOS inter-laboratory comparisons2017In: International Journal of Radiation Biology, ISSN 0955-3002, E-ISSN 1362-3095, Vol. 93, no 1, p. 99-109Article in journal (Refereed)
    Abstract [en]

    Purpose: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. Materials and methods: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation induced thermoluminescent signals in glass screens taken from mobile phones. Results: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. Conclusions: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios.

  • 46. Aitken, Candice L.
    et al.
    Gorniak, Richard J. T.
    New York University.
    Kramer, Elissa L.
    New York University.
    Noz, Marilyn E.
    New York University.
    Farrell, Eward J.
    IBM Research.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Reddy, David P.
    Comparison of three methods used for fusion of SPECT-CT images of liver matastases1998In: Fusion98, International Conference on Multisource-Mulltisensor Information Fusion / [ed] Hamid R. Arabnia and Dongping (Daniel) Zhu, CSREA Press , 1998, p. 435-442Conference paper (Refereed)
    Abstract [en]

    We compare three methods for fusing SPECT-CT images: ImageMatch - an automatic three-dimensional/two-dimensional method developed by Focus Imaging; IBM Visualization Data Explorer - a three-diemensional interactive method developed by Internation Business Machines, Inc.; and qsh - an interactive three-dimensional/two-dimensional method developed at New York University. While many fusion methods have proved successful for registering brain images, most methods have been less successful for thoracic and abdominal images. We use images of liver metastases obtained with a radiolabeled breast tumor-directed antibody to illustrate the strengths and weakness of the methods reviewed. The images used are typical clinical images from eigth patients. We conclude that an optimal image fusion program should combine the strengths of each of the methods reviewed.

  • 47. Aitken, Candice L.
    et al.
    Mahmoud, Faaiza
    McGuinness, Georgeann
    Kramer, Elissa L.
    Maguire, Gerald Q. Jr.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Noz, Marilyn E.
    New York University.
    Tumor localization and image registration of F-18FDG coincidence detection scans with computed tomographic scans2002In: Clinical Nuclear Medicine, ISSN 0363-9762, E-ISSN 1536-0229, Vol. 27, no 4, p. 275-282Article in journal (Refereed)
    Abstract [en]

    Purpose: The aim of this study was to determine the feasibility of registering routine clinical F-18 fluorodeoxyglucose (FDG) coincidence detection (CD) scans with computed tomographic (CT) scans for radiation treatment planning and case management. Methods: F-18 FDG CD and chest CT scans, performed in 10 randomly selected patients with confirmed or possible adenocarcinoma of the lung, were evaluated. The quality of the matches was verified by comparisons of the center-to-center distance between a region of interest (ROI) manually drawn on the CT slice and warped onto the CD slice with an ROI drawn manually directly on the CD slice. In addition, the overlap between the two ROIs was calculated. Results: All 10 F-18 FDG CD and CT scans were registered with good superimposition of soft tissue density on increased radionuclide activity. The center-to-center distance between the ROIs ranged from 0.29 mm to 8.08 mm, with an average center-to-center distance of 3.89 mm 2.42 mm (0.69 pixels +/- 0.34 pixels). The ROI overlap ranged from 77% to 99%, with an average of 90% +/- 5.6%. Conclusions: Although the use of F-18 FDG CD shows great promise for the identification of tumors, it shares the same drawbacks as those associated with radiolabeled monoclonal antibody SPECT and ligand-based positron emission tomographic scans in that anatomic markers are limited. This study shows that image registration is feasible and may improve the clinical relevance of CD images.

  • 48.
    Aitken, Candice L.
    et al.
    New York University.
    McGuinness, Georgeann
    New York University.
    Siddiqui, Faaiza
    New York University.
    Ton, Anthony
    New York University.
    Kramer, Elissa L
    New York University.
    Maguire Jr., Gerald Q.
    KTH, Superseded Departments, Teleinformatics.
    Noz, Marilyn E.
    New York University, Department of Radiology.
    Tumor localization and image registration of 18-FDG SPECT scans with CT scans1999In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 40, no 5, p. 290P-291PArticle in journal (Refereed)
    Abstract [en]

    PURPOSE:

    The aim of this study was to determine the feasibility of registering routine clinical F-18 fluorodeoxyglucose (FDG) coincidence detection (CD) scans with computed tomographic (CT) scans for radiation treatment planning and case management.

    METHODS:

    F-18 FDG CD and chest CT scans, performed in 10 randomly selected patients with confirmed or possible adenocarcinoma of the lung, were evaluated. The quality of the matches was verified by comparisons of the center-to-center distance between a region of interest (ROI) manually drawn on the CT slice and warped onto the CD slice with an ROI drawn manually directly on the CD slice. In addition, the overlap between the two ROIs was calculated.

    RESULTS:

    All 10 F-18 FDG CD and CT scans were registered with good superimposition of soft tissue density on increased radionuclide activity. The center-to-center distance between the ROIs ranged from 0.29 mm to 8.08 mm, with an average center-to-center distance of 3.89 mm +/- 2.42 mm (0.69 pixels +/- 0.34 pixels). The ROI overlap ranged from 77% to 99%, with an average of 90% +/- 5.6%.

    CONCLUSIONS:

    Although the use of F-18 FDG CD shows great promise for the identification of tumors, it shares the same drawbacks as those associated with radiolabeled monoclonal antibody SPECT and ligand-based positron emission tomographic scans in that anatomic markers are limited. This study shows that image registration is feasible and may improve the clinical relevance of CD images.

  • 49.
    Ajithkumar, Thankamma
    et al.
    Cambridge Univ Hosp, Dept Oncol, Cambridge, England.
    Horan, Gail
    Cambridge Univ Hosp, Dept Oncol, Cambridge, England.
    Padovani, Laetitia
    Assistance Publ Hop Marseille, Dept Radiat Oncol, Marseille, France.
    Thorp, Nicky
    Clatterbridge Canc Ctr, Dept Oncol, Liverpool, Merseyside, England.
    Timmermann, Beate
    Univ Essen Gesamthsch, West German Proton Ctr, Essen, Germany.
    Alapetite, Claire
    Inst Curie, Dept Radiat Oncol, Paris, France;Inst Curie, Proton Ctr, Paris, France;Inst Curie, Dept Radiat Oncol, Orsay, France;Inst Curie, Proton Ctr, Orsay, France.
    Gandola, Lorenza
    Fdn IRCCS Ist Nazl Tumori, Dept Radiat Oncol, Milan, Italy.
    Ramos, Monica
    Hosp Univ Vall dHebron, Barcelona, Spain.
    Van Beek, Karen
    UZ Leuven, Radiotherapie Oncol, Leuven, Belgium.
    Christiaens, Melissa
    UZ Leuven, Radiotherapie Oncol, Leuven, Belgium.
    Lassen-Ramshad, Yasmin
    Aarhus Univ Hosp, Danish Ctr Particle Therapy, Aarhus, Denmark.
    Magelssen, Henriette
    Norwegian Radium Hosp, Oslo Univ Hosp, Dept Oncol, Oslo, Norway.
    Nilsson, Kristina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Saran, Frank
    Royal Marsden Hosp, Dept Oncol, Sutton, Surrey, England.
    Rombi, Barbara
    Santa Chiara Hosp, Proton Therapy Ctr, Trento, Italy.
    Kortmann, Rolf
    Univ Leipzig, Dept Radiat Oncol, Leipzig, Germany.
    Janssens, Geert O.
    Univ Med Ctr Utrecht, Dept Radiat Oncol, Utrecht, Netherlands;Princess Maxima Ctr Pediat Oncol, Utrecht, Netherlands.
    SIOPE - Brain tumor group consensus guideline on craniospinal target volume delineation for high-precision radiotherapy2018In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 128, no 2, p. 192-197Article in journal (Refereed)
    Abstract [en]

    Objective: To develop a consensus guideline for craniospinal target volume (TV) delineation in children and young adults participating in SIOPE studies in the era of high-precision radiotherapy. Methods and materials: During four consensus meetings (Cambridge, Essen, Liverpool, and Marseille), conventional field-based TV has been translated into image-guided high-precision craniospinal TV by a group of expert paediatric radiation oncologists and enhanced by MRI images of liquor distribution. Results: The CTVcranial should include the whole brain, cribriform plate, most inferior part of the temporal lobes, and the pituitary fossa. If the full length of both optic nerves is not included, the dose received by different volumes of optic nerve should be recorded to correlate with future patterns of relapse (no consensus). The CTVcranial should be modified to include the dural cuffs of cranial nerves as they pass through the skull base foramina. Attempts to spare the cochlea by excluding CSF within the internal auditory canal should be avoided. The CTVspinal should include the entire subarachnoid space, including nerve roots laterally. The lower limit of the spinal CTV is at the lower limit of the thecal sac, best visible on MRI scan. There is no need to include sacral root canals in the spinal CTV. Conclusion: This consensus guideline has the potential to improve consistency of craniospinal TV delineation in an era of high-precision radiotherapy. This proposal will be incorporated in the RTQA guidelines of future SIOPE-BTG trials using CSI.

  • 50.
    Akhtari, Mohammad Mehdi
    Umeå University, Faculty of Science and Technology, Department of Physics. Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    3D Structural similarity check between CT and SCT2014Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the current work was to develop and test a method for comparing the geometrical representation of a patient using computed tomography (CT), and CT like images derived from magnetic resonance images (MRI). It would be beneficial to use MRI alone for both target delineation and treatment planning to save time and costs. This was first investigated in Umea university Hospital by introducing substitute computed tomography (SCT) obtained from MRI images and which can be used as CT equivalent information. The data that is used in this report are from five patients with intracranial tumors; A MATLAB code has been developed to compare DDRs based on s-CT data with CT based DRR’s for these five patients.

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