| 1. |
- Asplund, Sara, 1976, et al.
(author)
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Extended analysis of the effect of learning with feedback on the detectability of pulmonary nodules in chest tomosynthesis
- 2011
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In: Progress in Biomedical Optics and Imaging - Proceedings of SPIE. - : SPIE. - 1605-7422. ; 7966
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Journal article (other academic/artistic)abstract
- In chest tomosynthesis, low-dose projections collected over a limited angular range are used for reconstruction of section images of the chest, resulting in a reduction of disturbing anatomy at a moderate increase in radiation dose compared to chest radiography. In a previous study, we investigated the effects of learning with feedback on the detection of pulmonary nodules in chest tomosynthesis. Six observers with varying degrees of experience of chest tomosynthesis analyzed tomosynthesis cases for presence of pulmonary nodules. The cases were analyzed before and after learning with feedback. Multidetector computed tomography (MDCT) was used as reference. The differences in performance between the two readings were calculated using the jackknife alternative free-response receiver operating characteristics (JAFROC-2) as primary measure of detectability. Significant differences between the readings were found only for observers inexperienced in chest tomosynthesis. The purpose of the present study was to extend the statistical analysis of the results of the previous study, including JAFROC-1 analysis and FROC curves in the analysis. The results are consistent with the results of the previous study and, furthermore, JAFROC-1 gave lower p-values than JAFROC-2 for the observers who improved their performance after learning with feedback. © 2011 SPIE.
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| 3. |
- Asplund, Sara, 1976, et al.
(author)
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Learning aspects and potential pitfalls regarding detection of pulmonary nodules in chest tomosynthesis and proposed related quality criteria.
- 2011
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In: Acta radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 52:5, s. 503-512
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Journal article (peer-reviewed)abstract
- Background In chest tomosynthesis, low-dose projections collected over a limited angular range are used for reconstruction of an arbitrary number of section images of the chest, resulting in a moderately increased radiation dose compared to chest radiography. Purpose To investigate the effects of learning with feedback on the detection of pulmonary nodules for observers with varying experience of chest tomosynthesis, to identify pitfalls regarding detection of pulmonary nodules, and present suggestions for how to avoid them, and to adapt the European quality criteria for chest radiography and computed tomography (CT) to chest tomosynthesis. Material and Methods Six observers analyzed tomosynthesis cases for presence of nodules in a jackknife alternative free-response receiver-operating characteristics (JAFROC) study. CT was used as reference. The same tomosynthesis cases were analyzed before and after learning with feedback, which included a collective learning session. The difference in performance between the two readings was calculated using the JAFROC figure of merit as principal measure of detectability. Results Significant improvement in performance after learning with feedback was found only for observers inexperienced in tomosynthesis. At the collective learning session, localization of pleural and subpleural nodules or structures was identified as the main difficulty in analyzing tomosynthesis images. Conclusion The results indicate that inexperienced observers can reach a high level of performance regarding nodule detection in tomosynthesis after learning with feedback and that the main problem with chest tomosynthesis is related to the limited depth resolution.
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| 10. |
- Johnsson, Hans-Roland, 1957-
(author)
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Victor Hugo mellan Gud och Människa
- 2010
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In: Poeter och profeter; från Platon till Mare Kandre. - Hedemora / Möklinta : Gidlunds förlag. - 9789178447909
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Book chapter (other academic/artistic)
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| 11. |
- Lassila, Riitta, et al.
(author)
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Practical Viewpoints on the Diagnosis and Management of Heparin-Induced Thrombocytopenia
- 2011
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In: Seminars in Thrombosis and Hemostasis. - : Georg Thieme Verlag KG. - 1098-9064 .- 0094-6176. ; 37:3, s. 328-335
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Journal article (peer-reviewed)abstract
- Heparin-induced thrombocytopenia (HIT, type II) is an immune-mediated disorder due to antibodies formed against heparin platelet factor 4 complexes, usually appearing at days 5 to 14 after initiation of heparin. It is important to recognize HIT because heparin prophylaxis or treatment paradoxically associates with new venous and/or arterial thrombosis. Early clinical suspicion and diagnosis together with proper pharmacotherapy and close laboratory monitoring are the cornerstones for successful management. This includes monitoring of Thrombocytopenia, its Timing to heparin administration, appearance of new Thrombosis or resistance to treatment, and differential diagnosis by exclusion of oTher causes (the 4T's). Specific attention should be paid to the absence or presence of thrombosis and to tailoring thromboprophylaxis or anticoagulant therapy with a nonheparin alternative. Even in the absence of HIT-associated thrombosis, an active policy for prolonged thromboprophylaxis is demanded. Rapid and reliable assays should be developed for diagnosis and anticoagulation monitoring to secure safe management with nonheparins. Semiquantitative testing for on-call hours should be available and later confirmed as clinically needed. Alternative therapeutic options are available, but because their use is infrequent, experienced coagulation treatment centers should provide guidance in the treatment and in laboratory monitoring. Most of the evidence in HIT is grade IC, and thus the best evidence is provided by clinical experience. New anticoagulants and platelet inhibitors may offer future alternatives in the management of HIT, but the current treatment options provide the best experience and benefit. The joint clinical and laboratory guidelines provided in this article along with two practical case scenarios were prepared by a Nordic expert panel. They will be valuable for hematologists and colleagues who do not routinely encounter HIT.
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| 12. |
- Leitner, Torsten, 1979-, et al.
(author)
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Coherent wave packet dynamics in photo-excited Nal
- 2013
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In: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. - 9782759809561 ; 41, s. 02027-
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Journal article (other academic/artistic)abstract
- Time and energy resolved photoelectron distributions of photo-excited Nal are presented. A splitting in the photo-excited state suggested by calculations of the intramolecular potential energy surfaces could be confirmed experimentally for the first time.
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| 14. |
- Lymer, Gustav, 1978-, et al.
(author)
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Situated abstraction : From the particular to the general in second-order diagnostic work
- 2014
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In: Discourse Studies. - : SAGE Publications. - 1461-4456 .- 1461-7080. ; 16:2, s. 185-215
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Journal article (peer-reviewed)abstract
- The present study examines the work of a group of medical scientists as they identify interpretative ‘pitfalls’ – recurrent sources of error – in the use of a new radiographic technique, formulate suggestions on how these pitfalls can be avoided and communicate their findings in the form of a scientific publication. The analysis focuses on a session in which previously diagnosed cases are discussed, and demonstrates the ways in which a certain source of diagnostic error gradually emerges as a taken-for-granted in the interaction. An increased sense of recognition, recurrence and typicality is discernible in the treatment of the cases. Talk characterized by expansions and elaborations, displays of understanding in the form of reformulations, understanding checks, and so on, leave room for brief typifications and reifications of interpretative difficulties in characteristics of the imaging technique. Topical treatment of perception and interpretation, as well as embodied engagement, become decreasingly salient. It is argued that the abstracted formulations in the published text rely on the case-by-case working up of generality from particularity; from individualized accounts of why ‘I’ interpreted the image in a certain way to proffered generalizations achieved through articulated perceptions of a generalized ‘one’. If these proffers are ratified, a potential ground is established for the consensual formulation of a pitfall. The formulation of novel instructions is consequently made relevant, projecting a re-instructed diagnostic practice.
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| 15. |
- Nielsen, Niklas, et al.
(author)
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Target temperature management after out-of-hospital cardiac arrest-a randomized, parallel-group, assessor-blinded clinical trial-rationale and design
- 2012
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In: American Heart Journal. - : Elsevier. - 0002-8703 .- 1097-6744. ; 163:4, s. 541-548
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Journal article (peer-reviewed)abstract
- Background Experimental animal studies and previous randomized trials suggest an improvement in mortality and neurologic function with induced hypothermia after cardiac arrest. International guidelines advocate the use of a target temperature management of 32 degrees C to 34 degrees C for 12 to 24 hours after resuscitation from out-of-hospital cardiac arrest. A systematic review indicates that the evidence for recommending this intervention is inconclusive, and the GRADE level of evidence is low. Previous trials were small, with high risk of bias, evaluated select populations, and did not treat hyperthermia in the control groups. The optimal target temperature management strategy is not known. less thanbrgreater than less thanbrgreater thanMethods The TTM trial is an investigator-initiated, international, randomized, parallel-group, and assessor-blinded clinical trial designed to enroll at least 850 adult, unconscious patients resuscitated after out-of-hospital cardiac arrest of a presumed cardiac cause. The patients will be randomized to a target temperature management of either 33 degrees C or 36 degrees C after return of spontaneous circulation. In both groups, the intervention will last 36 hours. The primary outcome is all-cause mortality at maximal follow-up. The main secondary outcomes are the composite outcome of all-cause mortality and poor neurologic function (cerebral performance categories 3 and 4) at hospital discharge and at 180 days, cognitive status and quality of life at 180 days, assessment of safety and harm. less thanbrgreater than less thanbrgreater thanDiscussion The TTM trial will investigate potential benefit and harm of 2 target temperature strategies, both avoiding hyperthermia in a large proportion of the out-of-hospital cardiac arrest population.
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| 16. |
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| 17. |
- Rystedt, Hans, 1951, et al.
(author)
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Rediscovering radiology: New technologies and remedial action at the worksite
- 2011
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In: Social Studies of Science. - : SAGE Publications. - 0306-3127 .- 1460-3659. ; 41:6, s. 867-891
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Journal article (peer-reviewed)abstract
- This study contributes to social studies of imaging and visualization practices within scientific and medical settings. The focus is on practices in radiology, which are bound up with visual records known as radiographs. The study addresses work following the introduction of a new imaging technology, tomosynthesis. Since it was a novel technology, there was limited knowledge of howto correctly analyse tomosynthesis images. To address this problem, a collective review session was arranged. The purpose of the present study was to uncover the practical work that took place during that session and to show how, and on what basis, new methods, interpretations and understandings were being generated. The analysis displays how the diagnostic work on patients’ bodies was grounded in two sets of technologically produced renderings. This shows how expertise is not simply a matter of providing correct explanations, but also involves discovery work in which visual renderings are made transparent. Furthermore, the results point to how the disciplinary knowledge is intertwined with timely actions, which in turn, partly rely on established practices of manipulating and comparing images. The embodied and situated reasoning that enabled radiologists to discern objects in the images thus display expertise as inherently practical and domain-specific.
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| 18. |
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Samhällsdidaktik : sju aspekter på samhällsundervisning i skola och lärarutbildning
- 2012
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Editorial collection (other academic/artistic)abstract
- Samhällsdidaktik – sju aspekter på samhällsundervisning i skola och lärarutbildning är en antologi där sju forskare vid Linköpings universitet ventilerar olika sidor av samhällsundervisningens problematik och möjligheter, såsom hur samhällsundervisningens villkor ständigt förändras och konsekvenserna av detta, vilken roll teknikhistoria bör ha i grundskolan, hur gymnasieskolans nya kursplan i historia har påverkat läromedlen, innehållet i sponsrade läromedel, betydelsen av religionsundervisning i särskolan, hur staten främjar utbildning i samband med ett jubileum samt vikten av internationellt utbyte.
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| 19. |
- Söderman, Christina, et al.
(author)
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Application of a computed tomography based cystic fibrosis scoring system to chest tomosynthesis
- 2013
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In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 8673
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Journal article (other academic/artistic)abstract
- In the monitoring of progression of lung disease in patients with cystic fibrosis (CF), recurrent computed tomography (CT) examinations are often used. The relatively new imaging technique chest tomosynthesis (CTS) may be an interesting alternative in the follow-up of these patients due to its visualization of the chest in slices at radiation doses and costs significantly lower than is the case with CT. A first step towards introducing CTS imaging in the diagnostics of CF patients is to establish a scoring system appropriate for evaluating the severity of CF pulmonary disease based on findings in CTS images. Previously, several such CF scoring systems based on CT imaging have been published. The purpose of the present study was to develop a CF scoring system for CTS, by starting from an existing scoring system dedicated for CT images and making modifications regarded necessary to make it appropriate for use with CTS images. In order to determine any necessary changes, three thoracic radiologists independently used a scoring system dedicated for CT on both CT and CTS images from CF patients. The results of the scoring were jointly evaluated by all the observers, which lead to suggestions for changes to the scoring system. Suggested modifications include excluding the scoring of air trapping and doing the scoring of the findings in quadrants of the image instead of in each lung lobe. © 2013 SPIE.
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| 20. |
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| 21. |
- Tveit, Kjell Magne, et al.
(author)
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Phase III Trial of Cetuximab With Continuous or Intermittent Fluorouracil, Leucovorin, and Oxaliplatin (Nordic FLOX) Versus FLOX Alone in First-Line Treatment of Metastatic Colorectal Cancer : The NORDIC-VII Study
- 2012
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In: Journal of Clinical Oncology. - : American Society of Clinical Oncology: JCO. - 0732-183X .- 1527-7755. ; 30:15, s. 1755-1762
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Journal article (peer-reviewed)abstract
- Purpose: The NORDIC-VII multicenter phase III trial investigated the efficacy of cetuximab when added to bolus fluorouracil/folinic acid and oxaliplatin (Nordic FLOX), administered continuously or intermittently, in previously untreated metastatic colorectal cancer (mCRC). The influence of KRAS mutation status on treatment outcome was also investigated. Patients and Methods: Patients were randomly assigned to receive either standard Nordic FLOX (arm A), cetuximab and FLOX (arm B), or cetuximab combined with intermittent FLOX (arm C). Primary end point was progression-free survival (PFS). Overall survival (OS), response rate, R0 resection rate, and safety were secondary end points. Results: Of the 571 patients randomly assigned, 566 were evaluable in intention-to-treat (ITT) analyses. KRAS and BRAF mutation analyses were obtained in 498 (88%) and 457 patients (81%), respectively. KRAS mutations were present in 39% of the tumors; 12% of tumors had BRAF mutations. The presence of BRAF mutations was a strong negative prognostic factor. In the ITT population, median PFS was 7.9, 8.3, and 7.3 months for the three arms, respectively (not significantly different). OS was almost identical for the three groups (20.4, 19.7, 20.3 months, respectively), and confirmed response rates were 41%, 49%, and 47%, respectively. In patients with KRAS wild-type tumors, cetuximab did not provide any additional benefit compared with FLOX alone. In patients with KRAS mutations, no significant difference was detected, although a trend toward improved PFS was observed in arm B. The regimens were well tolerated. Conclusion: Cetuximab did not add significant benefit to the Nordic FLOX regimen in first-line treatment of mCRC.
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| 22. |
- Yar, Mazher Ahmed, et al.
(author)
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Chemically produced nanostructured ODS-lanthanum oxide-tungsten composites sintered by spark plasma
- 2011
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 408:2, s. 129-135
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Journal article (peer-reviewed)abstract
- High purity W and W-0.9La(2)O(3) (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous solutions. High resolution electron microscopy investigations revealed that the tungstate particles were coated with oxide precipitates. The precursor powder was reduced to tungsten metal with dispersed lanthanum oxide. Powders were consolidated by spark plasma sintering (SPS) at 1300 and 1400 degrees C to suppress grain growth during sintering. The final grain size relates to the SPS conditions, i.e. temperature and heating rate, regardless of the starting powder particle size. Scanning electron microscopy revealed that oxide phases were mainly accumulated at grain boundaries while the tungsten matrix constituted of nanosized sub-grains. The transmission electron microscopy revealed that the tungsten grains consist of micron-scale grains and finer sub-grains. EDX analysis confirmed the presence of W in dispersed oxide phases with varying chemical composition, which evidenced the presence of complex oxide phases (WO-La) in the sintered metals.
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| 23. |
- Yar, Mazher Ahmed, et al.
(author)
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Spark plasma sintering of tungsten-yttrium oxide composites from chemically synthesized nanopowders and microstructural characterization
- 2011
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In: Journal of Nuclear Materials. - : Elsevier BV. - 0022-3115 .- 1873-4820. ; 412:2, s. 227-232
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Journal article (peer-reviewed)abstract
- Nano-crystalline W-1%Y2O3 (wt.%) powder was produced by a modified solution chemical reaction of ammonium paratungstate (APT) and yttrium nitrate. The precursor powder was found to consist of particles of bimodal morphology i.e. large APT-like particles up to 20 pm and rectangular yttrium containing ultrafine plates. After thermal processing tungsten crystals were evolved from W-O-Y plate like particles. spark plasma sintering (SPS) was used to consolidate the powder at 1100 and 1200 degrees C for different holding times in order to optimize the sintering conditions to yield high density but with reduced grain growth. Dispersion of yttrium oxide enhanced the sinterability of W powder with respect to lanthanum oxide. W-1%Y2O3 composites with sub-micron grain size showed improved density and mechanical properties as compared to W-La2O3 composites. Sample sintered in two steps showed improved density, due to longer holding time at lower temperature (900 degrees C) and less grain growth due to shorter holding time at higher temperature i.e. 1 min at 1100 degrees C.
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