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  • 1.
    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
  • 2.
    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)
  • 3.
    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.

  • 4.
    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)
  • 5.
    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.

  • 6.
    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.

  • 7.
    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.

  • 8.
    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
  • 9.
    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
  • 10.
    Alshamari, Muhammed
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Geijer, Mats
    Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden; Lund University, Lund, Sweden.
    Norrman, Eva
    Örebro University Hospital.
    Geijer, Håkan
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Low-dose computed tomography of the lumbar spine: a phantom study on imaging parameters and image quality2014In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 55, no 7, p. 824-832Article in journal (Refereed)
    Abstract [en]

    Background: Lumbar spine radiography has limited diagnostic value but low radiation dose compared with computed tomography (CT). The average effective radiation dose from lumbar spine radiography is about 1.1 mSv. Low-dose lumbar spine CT may be an alternative to increase the diagnostic value at low radiation dose, around 1 mSv.

    Purpose: To determine the optimal settings for low-dose lumbar spine CT simultaneously aiming for the highest diagnostic image quality possible.

    Material and Methods: An ovine lower thoracic and lumbar spine phantom, with all soft tissues around the vertebrae preserved except the skin, was placed in a 20 L plastic container filled with water. The phantom was scanned repeatedly with various technical settings; different tube potential, reference mAs, and with different convolution filters. Five radiologists evaluated the image quality according to a modification of the European guidelines for multislice computed tomography (MSCT) quality criteria for lumbar spine CT 2004. In a visual comparison the different scans were also ranked subjectively according to perceived image quality. Image noise and contrast were measured.

    Results: A tube potential of 120 kV with reference mAs 30 and medium or medium smooth convolution filter gave the best image quality at a sub-millisievert dose level, i.e. with an effective dose comparable to that from lumbar spine radiography.

    Conclusion: Low-dose lumbar spine CT thus opens a possibility to substitute lumbar spine radiography with CT without obvious increase in radiation dose.

  • 11.
    Alshamari, Muhammed
    et al.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Geijer, Mats
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden; Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden.
    Norrman, Eva
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.
    Lidén, Mats
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Krauss, Wolfgang
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Jendeberg, Johan
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Magnuson, Anders
    Örebro University Hospital.
    Geijer, Håkan
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Impact of iterative reconstruction on image quality of low-dose CT of the lumbar spine2017In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, no 6, p. 702-709Article in journal (Refereed)
    Abstract [en]

    Background: Iterative reconstruction (IR) is a recent reconstruction algorithm for computed tomography (CT) that can be used instead of the standard algorithm, filtered back projection (FBP), to reduce radiation dose and/or improve image quality.

    Purpose: To evaluate and compare the image quality of low-dose CT of the lumbar spine reconstructed with IR to conventional FBP, without further reduction of radiation dose.

    Material and Methods: Low-dose CT on 55 patients was performed on a Siemens scanner using 120 kV tube voltage, 30 reference mAs, and automatic dose modulation. From raw CT data, lumbar spine CT images were reconstructed with a medium filter (B41f) using FBP and four levels of IR (levels 2-5). Five reviewers scored all images on seven image quality criteria according to the European guidelines on quality criteria for CT, using a five-grade scale. A side-by-side comparison was also performed.

    Results: There was significant improvement in image quality for IR (levels 2-4) compared to FBP. According to visual grading regression, odds ratios of all criteria with 95% confidence intervals for IR2, IR3, IR4, and IR5 were: 1.59 (1.39-1.83), 1.74 (1.51-1.99), 1.68 (1.46-1.93), and 1.08 (0.94-1.23), respectively. In the side-by-side comparison of all reconstructions, images with IR (levels 2-4) received the highest scores. The mean overall CTDIvol was 1.70 mGy (SD 0.46; range, 1.01-3.83 mGy). Image noise decreased in a linear fashion with increased strength of IR.

    Conclusion: Iterative reconstruction at levels 2, 3, and 4 improves image quality of low-dose CT of the lumbar spine compared to FPB.

  • 12.
    Alshamari, Muhammed
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Geijer, Mats
    Department of Medical Imaging and Physiology, Skåne University Hospital, Lund University, Lund, Sweden.
    Norrman, Eva
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Medical Physics,, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Lidén, Mats
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Krauss, Wolfgang
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Wilamowski, Franciszek
    Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Geijer, Håkan
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Low dose CT of the lumbar spine compared with radiography: a study on image quality with implications for clinical practice2016In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, no 5, p. 602-611Article in journal (Refereed)
    Abstract [en]

    Background: Lumbar spine radiography is often performed instead of CT for radiation dose concerns.

    Purpose: To compare image quality and diagnostic information from low dose lumbar spine CT at an effective dose of about 1 mSv with lumbar spine radiography.

    Material and Methods: Fifty-one patients were examined by both methods. Five reviewers scored all examinations on eight image quality criteria using a five-graded scale and also assessed three common pathologic changes.

    Results: Low dose CT scored better than radiography on the following: sharp reproduction of disc profile and vertebral end-plates (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3-2.5), intervertebral foramina and pedicles (OR, 4.3; 95% CI, 3.1-5.9), intervertebral joints (OR, 139; 95% CI, 59-326), spinous and transverse processes (OR, 7.0; 95% CI, 4.3-11.2), sacro-iliac joints (OR, 4.2; 95% CI, 3.2-5.7), reproduction of the adjacent soft tissues (OR, 2.9; 95% CI, 2.1-4.0), and absence of any obscuring superimposed gastrointestinal gas and contents (OR, 188; 95% CI, 66-539). Radiography scored better on sharp reproduction of cortical and trabecular bone (OR, 0.3; 95% CI, 0.2-0.4). The reviewers visualized disk degeneration, spondylosis/diffuse idiopathic skeletal hyperostosis (DISH) and intervertebral joint osteoarthritis more clearly and were more certain with low dose CT. Mean time to review low dose CT was 204 s (95% CI, 194-214 s.), radiography 152 s (95% CI, 146-158 s.). The effective dose for low dose CT was 1.0-1.1 mSv, for radiography 0.7 mSv.

    Conclusion: Low dose lumbar spine CT at about 1 mSv has superior image quality to lumbar spine radiography with more anatomical and diagnostic information.

  • 13.
    Alshamari, Muhammed
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Norrman, Eva
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.
    Geijer, Mats
    Department of Medical Imaging and Physiology, Lund University, Lund, Sweden; Skåne University Hospital, Lund, Sweden.
    Jansson, Kjell
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Surgery, Örebro University Hospital, Örebro, Sweden.
    Geijer, Håkan
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review2016In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 26, no 6, p. 1766-1774Article in journal (Refereed)
    Abstract [en]

    Objectives: Abdominal radiography is frequently used in acute abdominal non-traumatic pain despite the availability of more advanced diagnostic modalities. This study evaluates the diagnostic accuracy of low-dose CT compared with abdominal radiography, at similar radiation dose levels.

    Methods: Fifty-eight patients were imaged with both methods and were reviewed independently by three radiologists. The reference standard was obtained from the diagnosis in medical records. Sensitivity and specificity were calculated. A systematic review was performed after a literature search, finding a total of six relevant studies including the present.

    Results: Overall sensitivity with 95 % CI for CT was 75 % (66-83 %) and 46 % (37-56 %) for radiography. Specificity was 87 % (77-94 %) for both methods. In the systematic review the overall sensitivity for CT varied between 75 and 96 % with specificity from 83 to 95 % while the overall sensitivity for abdominal radiography varied between 30 and 77 % with specificity 75 to 88 %.

    Conclusions: Based on the current study and available evidence, low-dose CT has higher diagnostic accuracy than abdominal radiography and it should, where logistically possible, replace abdominal radiography in the workup of adult patients with acute non-traumatic abdominal pain.

    Key points: • Low-dose CT has a higher diagnostic accuracy than radiography. • A systematic review shows that CT has better diagnostic accuracy than radiography. • Radiography has no place in the workup of acute non-traumatic abdominal pain.

  • 14.
    Andersson, Karin M.
    et al.
    Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.
    Ahnesjo, Anders
    Uppsala University, Uppsala, Sweden.
    Vallhagen Dahlgren, Christina
    Skandionkliniken, Uppsala, Sweden..
    Evaluation of a metal artifact reduction algorithm in CT studies used for proton radiotherapy treatment planning2014In: Journal of Applied Clinical Medical Physics, ISSN 1526-9914, E-ISSN 1526-9914, Vol. 15, no 5, p. 112-119Article in journal (Refereed)
    Abstract [en]

    Metal objects in the body such as hip prostheses cause artifacts in CT images. When CT images degraded by artifacts are used for treatment planning of radiotherapy, the artifacts can yield inaccurate dose calculations and, for particle beams, erroneous penetration depths. A metal artifact reduction software (O-MAR) installed on a Philips Brilliance Big Bore CT has been tested for applications in treatment planning of proton radiotherapy. Hip prostheses mounted in a water phantom were used as test objects. Images without metal objects were acquired and used as reference data for the analysis of artifact-affected regions outside of the metal objects in both the O-MAR corrected and the uncorrected images. Water equivalent thicknesses (WET) based on proton stopping power data were calculated to quantify differences in the calculated proton beam penetration for the different image sets. The WET to a selected point of interest between the hip prostheses was calculated for several beam directions of clinical relevance. The results show that the calculated differences in WET relative to the reference case were decreased when the O-MAR algorithm was applied. WET differences up to 2.0 cm were seen in the uncorrected case while, for the O-MAR corrected case, the maximum difference was decreased to 0.4 cm. The O-MAR algorithm can significantly improve the accuracy in proton range calculations. However, there are some residual effects, and the use of proton beam directions along artifact streaks should only be used with caution and appropriate margins.

  • 15.
    Andersson, Karin M.
    et al.
    Department of Medical Physics, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.
    Norrman, Eva
    Department of Medical Physics, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Geijer, Håkan
    Örebro University, School of Medical Sciences. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Krauss, Wolfgang
    Örebro University, School of Medical Sciences. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Cao, Yang
    Clinical Epidemiology and Biostatistics, School of Medical Sciences, Örebro University, Örebro, Sweden; Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden.
    Jendeberg, Johan
    Örebro University, School of Medical Sciences. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Geijer, Mats
    Department of Radiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden.
    Lidén, Mats
    Örebro University, School of Medical Sciences. Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Thunberg, Per
    Örebro University, School of Medical Sciences. Department of Medical Physics, Örebro University Hospital, Örebro, Sweden .
    Visual grading evaluation of commercially available metal artefact reduction techniques in hip prosthesis computed tomography2016In: British Journal of Radiology, ISSN 0007-1285, E-ISSN 1748-880X, Vol. 89, no 1063, article id 20150993Article in journal (Refereed)
    Abstract [en]

    Objectives: To evaluate metal artefact reduction (MAR) techniques from four computed tomography (CT) vendors in hip prosthesis imaging.

    Methods: Bilateral hip prosthesis phantom images, obtained by using MAR algorithms for single energy CT data or dual energy CT (DECT) data and by monoenergetic reconstructions of DECT data, were visually graded by five radiologists using ten image quality criteria. Comparisons between the MAR images and a reference image were performed for each scanner separately. Ordinal probit regression analysis was used.

    Results: The MAR algorithms in general improved the image quality based on the majority of the criteria (up to between 8/10 and 10/10) with a statistically improvement in overall image quality (P<0.001). However, degradation of image quality, such as new artefacts, was seen in some cases. A few monoenergetic reconstruction series improved the image quality (P<0.004) for one of the DECT scanners, but it was only improved for some of the criteria (up to 5/10). Monoenergetic reconstructions resulted in worse image quality for the majority of the criteria (up to 7/10) for the other DECT scanner.

    Conclusions: The MAR algorithms improved the image quality of the hip prosthesis CT images. However, since additional artefacts and degradation of image quality were seen in some cases, all algorithms should be carefully evaluated for every clinical situation. Monoenergetic reconstructions were in general concluded to be insufficient for reducing metal artifacts. Advances in knowledge: Qualitative evaluation of the usefulness of several MAR techniques from different vendors in CT imaging of hip prosthesis.

  • 16.
    Andersson, Karin M.
    et al.
    Örebro University, School of Medical Sciences.
    Norrman, Eva
    Örebro University, School of Medical Sciences. Örebro University Hospital.
    Thunberg, Per
    Örebro University, School of Medical Sciences. Örebro University Hospital.
    Metal Artifacts in CT Imaging of Hip Prostheses: Evaluation of Metal Artifact Reduction Techniques Provided by Four Vendors2015Conference paper (Other academic)
    Abstract [en]

    PURPOSE: The aim of this study was to evaluate metal artifact reduction (MAR) techniques, provided by four vendors, in CT imaging of hip prostheses.

    METHOD AND MATERIALS: A water phantom containing hip prostheses mounted in calf bones was scanned with four CT scanners; Philips Ingenuity; Toshiba Aquilion ONE Vision edition; GE Discovery 750 HD and Siemens SOMATOM Definition Flash. An uncorrected (reference) image was obtained for every CT and compared with images acquired with the scanner specific MAR technique; either monoenergetic reconstruction of Dual Energy CT (DECT) data (GE and Siemens) or the use of a MAR algorithm software (Philips and Toshiba), or a combination of the two (GE). The MAR techniques were applied for varying tube voltage, kernel and reconstruction technique. The reference images were quantitatively compared to the MAR images by analyzing the noise and the CT number accuracy in region of interests (ROIs). Visual grading was performed by five radiologists based on ten image quality (IQ) criteria.

    RESULTS: The MAR algorithms implied a general noise reduction (by up to 77%) and improved IQ based on the majority of the visual grading criteria. The use of monoenergetic reconstructions of DECT data, without any MAR algorithm, did not decrease the noise in the ROIs to the same extent as the MAR algorithms (up to 41%) and did even increase the noise in one ROI. The visual grading evaluation showed that monoenergetic reconstructions in general degraded the IQ for one of the DECT scanners and improved the IQ for only a few of the criteria for the other DECT scanner.

    CONCLUSION: The quantitative analysis and the visual grading evaluation showed that the IQ was generally improved when the MAR algorithms were used. However, additional artifacts and degradation of the IQ were noted in some MAR image regions. The use of monoenergetic reconstruction was concluded to not reduce metal artifacts to the same extent as the MAR algorithms and to even degrade the IQ in several image regions.

    CLINICAL RELEVANCE/APPLICATION: This study points out advantages and potential risks of using MAR techniques in CT imaging of hip prostheses and will be useful for clinics when optimizing CT scan protocols and purchasing new CT systems.

  • 17.
    Andersson, Karin M.
    et al.
    Örebro University, School of Medical Sciences.
    Nowik, P.
    Department of Medical Physics, Karolinska University Hospital, Stockholm, Sweden.
    Persliden, Jan
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Medical Physics, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Thunberg, Per
    Department of Medical Physics, Örebro University Hospital, Örebro, Sweden.
    Norrman, Eva
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Medical Physics, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Metal artefact reduction in CT imaging of hip prostheses-an evaluation of commercial techniques provided by four vendors2015In: British Journal of Radiology, ISSN 0007-1285, E-ISSN 1748-880X, Vol. 88, no 1052, article id 20140473Article in journal (Refereed)
    Abstract [en]

    Objective: The aim of this study was to evaluate commercial metal artefact reduction (MAR) techniques in X-ray CT imaging of hip prostheses.

    Methods: Monoenergetic reconstructions of dual-energy CT (DECT) data and several different MAR algorithms, combined with single-energy CT or DECT, were evaluated by imaging a bilateral hip prosthesis phantom. The MAR images were compared with uncorrected images based on CT number accuracy and noise in different regions of interest.

    Results: The three MAR algorithms studied implied a general noise reduction (up to 67%, 74% and 77%) and an improvement in CT number accuracy, both in regions close to the prostheses and between the two prostheses. The application of monoenergetic reconstruction, without any MAR algorithm, did not decrease the noise in the regions close to the prostheses to the same extent as did the MAR algorithms and even increased the noise in the region between the prostheses.

    Conclusion: The MAR algorithms evaluated generally improved CT number accuracy and substantially reduced the noise in the hip prostheses phantom images, both close to the prostheses and between the two prostheses. The study showed that the monoenergetic reconstructions evaluated did not sufficiently reduce the severe metal artefact caused by large orthopaedic implants.

    Advances in knowledge: This study evaluates several commercially available MAR techniques in CT imaging of large orthopaedic implants.

  • 18.
    Andersson, Karin M.
    et al.
    Örebro University, School of Medical Sciences. Department of Medical Physics, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Vallhagen Dahlgren, C.
    The Skandion clinic, Uppsala, Sweden.
    Reizenstein, J.
    Department of Oncology, Örebro University Hospital, Örebro, Sweden; , Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Ahnesjö, A.
    Medical Radiation Sciences, Department of Immunology-Genetics and Pathology, Uppsala University, Uppsala, Sweden.
    Thunberg, Per
    Örebro University, School of Medical Sciences. Department of Medical Physics , Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Impact of Metal Artifacts on Proton Therapy Treatment Planning Accuracy2017In: 56th Annual Meeting of the Particle Therapy Cooperative Group (PTCOG) 8-13 May 2017: Proceedings, The Particle Therapy Cooperative Group , 2017, Vol. 4, p. 68-68, article id 1Conference paper (Other academic)
    Abstract [en]

    Purpose: To evaluate for proton therapy treatment planning the feasibility of two commercial metal artifact reduction (MAR) algorithms in CT-imaging.

    Materials and Methods: A head phantom with removable dental fillings and a body phantom with a removable hip prosthesis were scanned to evaluate O-MAR (Philips) and iMAR (Siemens). Reference images (scans without metal) were acquired and subtracted from the uncorrected (no MAR) and MAR-images. CT number-differences were mapped to differences in stopping power ratios to water. In addition, proton treatment plans for a parotid, tonsil and prostate-target were optimized based on uncorrected and MAR images and recalculated on reference images. Beams were arranged to not traverse metal, enabling evaluation of metal artifact impact on target coverage.

    Results: MAR algorithms reduced the most extreme dental filling artifacts, but residual artifacts still remained. iMAR reduced hip prosthesis artifacts to large extent, while considerable artifacts still were present with O-MAR. For parotid and tonsil-plans, D98%to PTV was nearly intact in the reference recalculations for both uncorrected and MAR-based plans, with maximum-difference,0.3%. For uncorrected prostate plans, D98%decreased more than 4% in the reference recalculation. For the iMAR prostate plan, D98%was almost identical in the reference recalculation (97.5% versus 97.4%). A slight D98%-decrease was seen in the reference for the O-MAR based plan (96.8% versus 97.5%).

    Conclusion: Hip prosthesis artifacts reduced target coverage accuracy, but it was substantially improved with MAR algorithms. Dental filling artifacts were moderately reduced with MAR, but did not substantially affect target coverage

  • 19.
    Andersson, Karin M.
    et al.
    Örebro University, School of Medical Sciences.
    Vallhagen Dahlgren, Christina
    The Skandion Clinic, Uppsala, Sweden.
    Reizenstein, Johan
    Department of Oncology, Faculty of Medicine and Health, Örebro University, Sweden.
    Cao, Yang
    Örebro University, School of Medical Sciences. Örebro University Hospital. Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Ahnesjö, Anders
    Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
    Thunberg, Per
    Örebro University, School of Medical Sciences.
    CT image metal artifacts in proton radiotherapy treatment planning: evaluation of two commercial correction algorithmsManuscript (preprint) (Other academic)
  • 20.
    Andersson, Karin M.
    et al.
    Örebro University, School of Health Sciences. The Skandion Clinic, Uppsala, Sweden.
    Vallhagen Dahlgren, Christina
    The Skandion Clinic, Uppsala, Sweden.
    Reizenstein, Johan
    Department of Oncology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Cao, Yang
    Örebro University, School of Medical Sciences. Örebro University Hospital. Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
    Ahnesjö, Anders
    Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
    Thunberg, Per
    Örebro University, School of Medical Sciences. Department of Medical Physics.
    Evaluation of two commercial CT metal artifact reduction algorithms for use in proton radiotherapy treatment planning in the head and neck area2018In: Medical physics (Lancaster), ISSN 0094-2405, Vol. 45, no 10, p. 4329-4344Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To evaluate two commercial CT metal artifact reduction (MAR) algorithms for use in proton treatment planning in the head and neck (H&N) area.

    METHODS: An anthropomorphic head phantom with removable metallic implants (dental fillings or neck implant) was CT-scanned to evaluate the O-MAR (Philips) and the iMAR (Siemens) algorithms. Reference images were acquired without any metallic implants in place. Water equivalent thickness (WET) was calculated for different path directions and compared between image sets. Images were also evaluated for use in proton treatment planning for parotid, tonsil, tongue base, and neck node targets. The beams were arranged so as to not traverse any metal prior to the target, enabling evaluation of the impact on dose calculation accuracy from artifacts surrounding the metal volume. Plans were compared based on γ analysis (1 mm distance-to-agreement/1% difference in local dose) and dose volume histogram metrics for targets and organs at risk (OARs). Visual grading evaluation of 30 dental implant patient MAR images was performed by three radiation oncologists.

    RESULTS: In the dental fillings images, ΔWET along a low-density streak was reduced from -17.0 to -4.3 mm with O-MAR and from -16.1 mm to -2.3 mm with iMAR, while for other directions the deviations were increased or approximately unchanged when the MAR algorithms were used. For the neck implant images, ΔWET was generally reduced with MAR but residual deviations remained (of up to -2.3 mm with O-MAR and of up to -1.5 mm with iMAR). The γ analysis comparing proton dose distributions for uncorrected/MAR plans and corresponding reference plans showed passing rates >98% of the voxels for all phantom plans. However, substantial dose differences were seen in areas of most severe artifacts (γ passing rates of down to 89% for some cases). MAR reduced the deviations in some cases, but not for all plans. For a single patient case dosimetrically evaluated, minor dose differences were seen between the uncorrected and MAR plans (γ passing rate approximately 97%). The visual grading of patient images showed that MAR significantly improved image quality (P < 0.001).

    CONCLUSIONS: O-MAR and iMAR significantly improved image quality in terms of anatomical visualization for target and OAR delineation in dental implant patient images. WET calculations along several directions, all outside the metallic regions, showed that both uncorrected and MAR images contained metal artifacts which could potentially lead to unacceptable errors in proton treatment planning. ΔWET was reduced by MAR in some areas, while increased or unchanged deviations were seen for other path directions. The proton treatment plans created for the phantom images showed overall acceptable dose distributions differences when compared to the reference cases, both for the uncorrected and MAR images. However, substantial dose distribution differences in the areas of most severe artifacts were seen for some plans, which were reduced by MAR in some cases but not all. In conclusion, MAR could be beneficial to use for proton treatment planning; however, case-by-case evaluations of the metal artifact-degraded images are always recommended.

  • 21.
    Andersson, Pernilla
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Barn och datortomografi: konsekvensen av att utsätta barn för joniserande strålning2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 22.
    Andersson, Torbjörn
    Örebro University, School of Health and Medical Sciences.
    Den digitala röntgenavdelningen2008In: Radiologi / [ed] Peter Aspelin, Holger Pettersson, Lund: Studentlitteratur , 2008, p. 125-134Chapter in book (Other academic)
  • 23.
    Baker Muhammad, Avan
    Örebro University, School of Health and Medical Sciences.
    Jämförelse av CT och PCT med MR-DW vid diagnostik av akut ischemisk stroke: – en litteraturstudie2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning

    Stroke är en samlingsbenämning för plötsligt insjuknande personer med neurologiska symptom som talsvårigheter, förlamning, domningar eller medvetanderubbningar. Stroke orsakas ofta av en blodpropp som täpper till en pulsåder i hjärnan och stoppar tillförseln av blod till en del av hjärnan, viket också kallas ischemisk stroke (hjärninfarkt).

    Syfte

    : Syftet med denna studie var att jämföra datortomografi (CT) och perfusion datortomografi (PCT) med diffusions magnetresonans (MR-DW) vid diagnostik av akut ischemisk stroke.

    Metod:

    Denna litteratur studie bygger på 10 vetenskapliga studier. Studierna söktes vid olika tillfällen i databasen PubMed.

    Resultat

    : Sex studier som jämförde CT med diffutionsviktad MR (MR-DW) ansåg att MR-DW är mycket känsligare än CT i att påvisa ischemiska förändringar hos patienter med akut ischemisk stroke. Resultat från tre studier som jämförde MR-DW med perfusion datortomografi (PCT) visade att dessa metoder är likvärdiga i att påvisa ischemiska skador vid akut stroke samt de är användbara när man väljer ut patienter för akut trombolysbehandling.

    Slutsats:

    I de flesta fall har diffusions MR en högre känslighet än CT i att påvisa tidiga ischemiska förändringar men ibland kan ischemiska skador liksom parenkymal hypoattenuation missas av MR-DW. Diffusions MR och CT- perfusion är lika värdefulla metoder för patienter med misstänkt akut stroke för att påvisa ischemiska förändingar

  • 24.
    Bark, Matthias
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Standardprojektioner av scaphoideum i det akuta skedet vid frakturfrågeställning2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 25.
    Berg, Joakim
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Skillnader mellan röntgensjuksköterskors och radiologers rutiner att godkänna eller inte godkänna frontalbilder på knäplastik2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bakgrund: Trikompartmentell knäartroplastik (TKA) är en vanlig behandlingsmetod vid artros. Vid bildtagning finns rekommendationer författade av Svensk Ortopedisk Förening. Dessa täcker inte knäledsrotation på en frontalbild. Syftet var att ta reda på skillnader mellan röntgensjuksköterskors och radiologers rutiner att godkänna/underkänna knäfrontalbilder med TKA ifall knät projicerats roterat.

    Metod: Genom en enkät bestående av två till fyra frågor om fem frontalbilder på knän med TKA som elva röntgensjuksköterskor och nio radiologer fick svara på samlades materialet in. Bilderna visade fem olika knän som i denna studie respektive bedömdes som rak, lite utåtroterad, mycketutåtroterad, lite inåtroterad samt mycket inåtroterad. Frågorna var: godkänd/underkänd bild, betyg på bild och ifall de ansett att bilden varit betydande roterad eller om något annat gjort att den inte blivit godkänd.

    Resultat: Om de svarande skulle godkänna bilden: Bild 1: 0 % av röntgensjuksköterskorna, 67 % av radiologerna. Bild 2: 91 % av röntgensjuksköterskorna, 100 % av radiolgerna. Bild 3: 45 % av röntgensjuksköterskorna, 67 % av radiologerna. Bild 4: 45 % av röntgensjuksköterskorna, 100 % avradiologerna. Bild 5: 18 % av röntgensjuksköterskorna, 100 % av radiologerna.

    Konklusion: Radiologerna hade större tolerans gentemot rotation av knäled med inopererad TKA jämfört med röntgensjuksköterskorna. Detta innebär att röntgensjuksköterskorna skulle ta om bildersom radiologer hade godkänt, vilket leder till onödig extra stråldos till patienter. Det var för litet urval för att dra någon slutsats, men om resultatet gäller nationellt bör tydliga rekommendationer författas gällande rotation vid bildtagning av frontalbilder på knäleder med inopererad TKA.

  • 26.
    Berglund, Lena
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Jämförelse av mammografi och MR vid kontroller av kvinnor med ärftlig risk för bröstcancer2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Abstrakt

    Syfte: Att undersöka om det finns det någon skillnad i precisionsförmågan hos mammografin och MR vid diagnostik av bröstcancer hos kvinnor med ärftlig risk.

    Bakgrund: Kvinnor under 30år har högre densitet i brösten än kvinnor över 50 år. 13 % av kvinnorna med ärftlig risk är BRCA1 och BRCA2-mutationsbärare. BRCA är två gener som lagar skadat DNA. En kvinna med BRCA mutation har 50-80% risk för bröstcancer. Screening av kvinnor med ärftlig risk kan genomföras med t.ex. mammografi, ultraljud och MR.

    Metod: Relevanta artiklar söktes via PubMed med hjälp av relevanta mesh-termer. Genom tre urval har 12 artiklar inkluderats i litteraturstudien. Artiklarna resultat granskades och sammanställdes objektivt.

    Resultat: Mediansensitivitet för mammografi var 40 % jämfört med 85 % för MR, skillnaden var 47 procentenheter till MRs fördel. Mammografi hade en medianspecificitet på 96 % och 85 % hos MR. Medianskillnaden var 9 % procentenheter till mammografins fördel. Flera artiklar antydde att MR ger ett högt falsk-positivt resultat. Olika resultat framkom vad det gäller hur små förändringar modaliteterna klarar av att finna.Konklusion: MR har högre sensitivitet än mammografi, vilket måste vägas mot MRs höga falsk-positiva värde i val av modalitet. Viss oenighet finns gällande om mammografi har högre specificitet än MR.

     

    Nyckelord: bröstcancer, ärftlig risk, mammografi och MR

  • 27.
    Bilos, Linda
    et al.
    Department of Cardiothoracic and Vascular Surgery, Örebro University Hospital, Örebro, Sweden; Örebro University, Örebro, Sweden.
    Pirouzram, Artai
    Örebro University, School of Medical Sciences. Department of Cardiothoracic and Vascular Surgery, Faculty of Medicine and Health, Örebro University Hospital, Örebro, Sweden.
    Toivola, Asko
    Department of Cardiothoracic and Vascular Surgery, Örebro University Hospital, Örebro, Sweden; Örebro University, Örebro, Sweden.
    Vidlund, Mårten
    Örebro University, School of Health Sciences. Department of Cardiothoracic and Vascular Surgery, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Cha, Soon Ok
    Department of Cardiothoracic and Vascular Surgery, Örebro University Hospital, Örebro, Sweden; Örebro University, Örebro, Sweden.
    Hörer, Tal
    Örebro University, School of Medical Sciences. Department of Cardiothoracic and Vascular Surgery, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    EndoVascular and Hybrid Trauma Management (EVTM) for Blunt Innominate Artery Injury with Ongoing Extravasation2017In: Cardiovascular and Interventional Radiology, ISSN 0174-1551, E-ISSN 1432-086X, Vol. 40, no 1, p. 130-134Article in journal (Refereed)
    Abstract [en]

    Innominate artery (IA) traumatic injuries are rare but life-threatening, with high mortality and morbidity. Open surgical repair is the treatment of choice but is technically demanding. We describe a case of blunt trauma to the IA with ongoing bleeding, treated successfully by combined (hybrid) endovascular and open surgery. The case demonstrates the immediate usage of modern endovascular and surgical tools as part of endovascular and hybrid trauma management.

  • 28.
    Blomfeldt, Amanda
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Frågor som ställs inför datortomografi med intravenösa jodkontrastmedel: en enkätstudie2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bakgrund: Förutom de diagnostiska fördelarna med jodkontrastmedel finns det samtidigt risker. Nedsatt njurfunktion, diabetes och hjärtsvikt är några av de riskfaktorer som kan leda till att patienten drabbas av en kontrastmedelsinducerad njurskada. Allergi och astma utgör riskfaktorer för en akut överkänslighetsreaktion. Tyreoideafunktion, graviditet och läkemedel är andra faktorer som är viktigt att ta reda på för att undvika negativa effekter av jodkontrastmedel. I Sverige finns nationella rekommendationer samt utarbetade frågeformulär som ska förebygga de negativa effekterna. Syfte: Syftet med studien var att undersöka användandet av utarbetade frågeformulär samt vilka frågor som ställs utifrån de nationella rekommendationerna inför intravenös administrering av jodkontrastmedel vid polikliniska datortomografiundersökningar. Metod: Studien var en empirisk kvantitativ studie och data samlades in med hjälp av en enkät. Enkäten skickades ut till landstingsdrivna röntgenkliniker som utför datortomografiundersökningar. Resultat: Det var 46 % av de röntgenkliniker som ingick i studien som använde utarbetade frågeformulär. De vanligaste frågorna som ställdes utifrån de nationella rekommendationerna var de om tidigare injektion av kontrastmedel, allergi, diabetes, metforminbehandling och graviditet. Frågan om astma, nedsatt njurfunktion, hjärtsvikt/hjärtbesvär, sköldkörtelproblem, myastenia gravis och intag av NSAID (non steroidal anti-inflammatory drugs) förekom i lägre grad vid de röntgenkliniker som ingick i studien. Samtliga frågor ställdes oftare av de röntgenkliniker som använde utarbetade frågeformulär.  Konklusion: Användandet av utarbetade frågeformulär och vilka frågor som ställs varierar bland de undersökta röntgenklinikerna. Ett utarbetat frågeformulär kan bidra till att viktiga frågor blir ställda inför administrering av jodkontrastmedel och på så sätt öka patientsäkerheten.

  • 29.
    Blomqvist, L.
    et al.
    Department of Diagnostic Radiology, Karolinska University Hospital, Solna, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden .
    Carlsson, S.
    Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Department of Urology, Karolinska University Hospital, Solna, Sweden.
    Gjertsson, P.
    Department of Clinical Physiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Heintz, E.
    The Swedish Council on Health Technology Assessment, Stockholm, Sweden.
    Hultcrantz, M.
    The Swedish Council on Health Technology Assessment, Stockholm, Sweden.
    Mejare, I.
    The Swedish Council on Health Technology Assessment, Stockholm, Sweden.
    Andrén, Ove
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Örebro University Hospital. Department of Urology, Örebro University Hospital, Örebro, Sweden.
    Limited evidence for the use of imaging to detect prostate cancer: a systematic review2014In: European Journal of Radiology, ISSN 0720-048X, E-ISSN 1872-7727, Vol. 83, no 9, p. 1601-1606Article, review/survey (Refereed)
    Abstract [en]

    Objective: To assess the diagnostic accuracy of imaging technologies for detecting prostate cancer in patients with elevated PSA-values or suspected findings on clinical examination.

    Methods: The databases Medline, EMBASE, Cochrane, CRD HTA/DARE/NHS EED and EconLit were searched until June 2013. Pre-determined inclusion criteria were used to select full text articles. Risk of bias in individual studies was rated according to QUADAS or AMSTAR. Abstracts and full text articles were assessed independently by two reviewers. The performance of diagnostic imaging was compared with systematic biopsies (reference standard) and sensitivity and specificity were calculated.

    Results: The literature search yielded 5141 abstracts, which were reviewed by two independent reviewers. Of these 4852 were excluded since they did not meet the inclusion criteria. 288 articles were reviewed in full text for quality assessment. Six studies, three using MRI and three using transrectal ultrasound were included. All were rated as high risk of bias. Relevant studies on PET/CT were not identified.

    Conclusion: Despite clinical use, there is insufficient evidence regarding the accuracy of imaging technologies for detecting cancer in patients with suspected prostate cancer using TRUS guided systematic biopsies as reference standard. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

  • 30.
    Bozovic, Gracijela
    et al.
    Department of Radiology, Skåne University Hospital, Lund University, Lund, Sweden.
    Adlercreutz, Catharina
    Department of Radiology, Skåne University Hospital, Lund University, Lund, Sweden.
    Höglund, Peter
    Deptartment Lab Medicine, Lund University, Lund, Sweden; Division Clinical Chemistry & Pharmacology, Lund University, Lund, Sweden.
    Björkman-Burtscher, Isabella
    Department of Radiology, Skåne University Hospital, Lund University, Lund, Sweden; Lund University Bioimaging Centre, Lund, Sweden .
    Reinstrup, Peter
    Departments of Neurosurgery, Skåne Universty Hospital, Lund, Sweden.
    Ingemansson, Richard
    Departments of Cardiothoracic Surgery, Skåne University Hospital, Lund, Sweden .
    Schaefer-Prokop, Cornelia
    Meander Medical Centre, Amersfoort, Netherlands .
    Siemund, Roger
    Department of Radiology, Skåne University Hospital, Lund University, Lund, Sweden.
    Geijer, Mats
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Clinical Sciences, Lund University, Lund, Sweden; Department of Radiology, Örebro University Hospital, Örebro, Sweden.
    Imaging of the Lungs in Organ Donors and its Clinical Relevance: A Retrospective Analysis2017In: Journal of thoracic imaging, ISSN 0883-5993, E-ISSN 1536-0237, Vol. 32, no 2, p. 107-114Article in journal (Refereed)
    Abstract [en]

    Purpose: The aim of the study was to retrospectively evaluate the diagnostic imaging that potential lung donors undergo, the reader variability of image interpretation and its relevance for donation, and the potential information gained from imaging studies not primarily intended for lung evaluation but partially including them.

    Materials and methods: Bedside chest radiography and computed tomography (CT), completely or incompletely including the lungs, of 110 brain-dead potential organ donors in a single institution during 2007 to 2014 were reviewed from a donation perspective. Two chest radiologists in consensus analyzed catheters and cardiovascular, parenchymal, and pleural findings. Clinical reports and study review were compared for substantial differences in findings that could have led to a treatment change, triggered additional examinations such as bronchoscopy, or were considered important for donation.

    Results: Among 136 bedside chest radiographs, no differences between clinical reports and study reviews were found in 37 (27%), minor differences were found in 28 (21%), and substantial differences were found in 71 (52%) examinations (P<0.0001). In 31 of 42 (74%) complete or incomplete CT examinations, 50 of 74 findings with relevance for lung donation were not primarily reported (P<0.0001).

    Conclusions: The majority of donor patients undergo only chest radiography. A targeted imaging review of abnormalities affecting the decision to use donor lungs may be useful in the preoperative stage. With a targeted list, substantial changes were made from initial clinical interpretations. CT can provide valuable information on donor lung pathology, even if the lungs are only partially imaged.

  • 31.
    Broxvall, Mathias
    et al.
    Örebro University, School of Science and Technology.
    Daoutis, Marios
    Örebro University, School of Science and Technology.
    Developing Medical Image Processing Algorithms for GPU assisted parallel computation2013In: Computer Vision in Medical Imaging / [ed] C H Chen, World Scientific, 2013, p. 245-270Chapter in book (Refereed)
    Abstract [en]

    GPU’s have recently emerged as a significantly more powerful computing plat-form, capable of several orders of magnitude faster computations compared toCPU based approaches. However, they require significant changes in the algorithmic design compared to traditional programming paradigms. In this chapter we specifically introduce the reader to an overview of GPGPU development tools and the potential algorithmic pitfalls and bottlenecks when developing medical imaging algorithms for the GPU. We present a few general methodologies and building blocks for implementing fast image processing on GPUs. More specifically they include: methods for performing fast image convolutions and filtering;line detection, and bandwidth and memory considerations when processing volumetric datasets. Finally we conclude with a discourse on numerical precision as well as on mixing single floating-point versus double floating-point code.

  • 32.
    Brunoson, Fredrik
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Skelettåldersmätning – en jämförelse mellan Greulich-Pyle och Tanner-Whitehouse2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 33.
    Bäck, Anna
    et al.
    Örebro University, School of Health Sciences. Department of Radiology.
    Savvopoulos, C.
    Department of Radiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Funk, Eva
    Örebro University, School of Health Sciences. Division of Medical Diagnostics.
    Geijer, Håkan
    Örebro University, School of Medical Sciences. Department of Radiology.
    Diuretic decision seven minutes post Tc-99m-MAG3 administration in a renography2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, no Suppl. 1, p. S765-S765, article id E-TPW52Article in journal (Other academic)
    Abstract [en]

    Aim: The F+10 method in supine position, which has been implemented at our Nuclear Medicine department since 2015, involves a 30- minute long dynamic acquisition. The diuretic is only administered when necessary and decision is taken by the radiographers in a semi-automated fashion without consulting a physician, by calculating the remaining activity in the kidneys seven minutes post 99mTc-MAG3 injection and comparing the value with an arbitrary threshold of 75 %. If needed, the diuretic is injected three minutes later. The aim of this study was to correlate our method with the established previously used F+20 protocol in adults. Is the currently used threshold of 75% of activity left in any kidney at seven minutes the optimal cut-off value for diuretic administration?

    Material and Methods: This is an ongoing retrospective study which include 320 F+20 examinations of adult patients performed during 2013-2015. They were all re-evaluated according to the currently used F+10 method, categorized as requiring diuretic or not and correlated to the original F+20 examination. A ROC-curve was drawn to delineate the best cut-off value for remaining renal activity. Sensitivity, specificity and accuracy were calculated.

    Results: Preliminary results indicate that the F+10 re-evaluations with the currently used cut-off value of 75% did not correlate with the original F+20 examinations. In 80% (255 examinations) of the F+10 re-evaluations diuretic would have been considered necessary while only 52% (167 examinations) received diuretics in the original F+20 renographies (sensitivity 1.0, specificity 0.42). However, all the patients who required furosemide in the original F+20 renographies would have received diuretic if they had been imaged with the F+10 protocol. Furthermore, examination time is considerably reduced. After an evaluation of the ROC-curve the optimal cut-off value was 94% (sensitivity 0.92, specificity 0.84, accuracy 0.88). However, by implementing this value, 13 patients (4%) would have been falsely categorized as not requiring diuretic.

    Conclusions: The 99mTc-MAG3 renography with the F+10 protocol in supine position is a feasible and acceptable method in clinical practice.

  • 34.
    Cetin, Fatma
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Reducerad stråldos till patienten vid datortomografi undersökning vid misstänkt lungemboli: En litteraturstudie2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 35.
    Danesh, Saghar
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Inbländningens påverkan på ländryggsfrontal2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning

    Bakgrund:

    Sjukvården använder sig av joniserande strålning för att ställa diagnos på patienter samt för behandling. Mätning av stråldos är nödvändigt för att optimera mängden strålning till patienten. As Low As Reasonbly Achievable (ALARA) är ett begrepp som innebär att strålningen bör optimeras till så låg mängd som möjligt utan att försvåra diagnostiken.

    Frågeställning och syfte:

    Syftet med studien var att fastställa om patientstråldosen vid frontalprojektion av ländrygg kan påverkas av inbländning. Uppsatsförfattaren ville också undersöka hur bildkvalitén (gällande bildkriterier) påverkas av inbländningen.

    Frågeställningar var hur påverkas patientstråldosen vid inbländning av ländryggsfrontal? Hur påverkas bildkvalitet gällande bildkriterie

    r vid inbländning av ländryggsfrontal?

    Metod:

    Ett experiment utfördes på Örebro Universitetssjukhus (USÖ) där ett Aldersonfantom användes. Fyra bilder exponerades med olika bländarstorlekar samt deras Dos Area Produkt (DAP-värdet) dokumenterades. Fem röntgensjuksköterskor bedömde bilderna enligt Visual Grading Analysis- metoden (VGA).

    Resultat:

    Bild ett som är referensbilden fick bländarstorleken 19x43 cm med DAP-värdet 0,61038 Graykvadratcentimeter (Gycm2). Därefter minskade bländarstorleken med två respektive en centimeter (cm) samt deras DAP-värde minskade. Den procentuella minskningen av DAP blev 20% mellan den största bländarstorleken och den minsta bländarstorleken. Resultatet av bildgranskningen såg varierande ut då fem röntgensjuksköterskor bedömde olika. Dock förkastades den minsta bländarstorleken av samtliga röntgensjuksköterskor.

    Slutsats:

    Enligt denna studie minskar DAP-värdet när bländarstorleken blir mindre. Dock ökar risken att bildkriterier inte uppfylls vid minskad bländarstorlek. Detta visar att inbländning av strålfältet är en viktig del i optimeringen.

    Nyckelord:

    DAP-värde, bländarstorlek, röntgensjuksköterskor,VGA.

  • 36.
    Dimitriou, Praxitelis
    et al.
    Department of Radiology, Örebro University Hospital , Örebro, Sweden.
    Kähäri, Anders
    Department of Clinical Physiology, Örebro University Hospital , Örebro, Sweden.
    Emilsson, Kent
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Clinical Physiology, Örebro University Hospital , Örebro, Sweden.
    Thunberg, Per
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Department of Medical Physics, Örebro University Hospital, Örebro, Sweden .
    Cardiovascular magnetic resonance imaging and transthoracic echocardiography in the assessment of stenotic aortic valve area: a comparative study2012In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 53, no 9, p. 995-1003Article in journal (Refereed)
    Abstract [en]

    Background: Magnetic resonance (MR) imaging and echocardiography both allow assessment of aortic valve stenosis. In MR the aortic valve area (AvA) is measured using planimetry while in transthoracic echocardiography (TTE) AvA is usually calculated by applying the continuity equation.

    Purpose: To compare the measured stenotic aortic valve areas using five different MR-acquisition alternatives with the corresponding area values calculated by TTE.

    Material and Methods: The aortic valve was imaged in 14 patients, with diagnosed aortic valve stenosis, using balanced steady state free precession (bSSFP) gradient echo (GE) and phase contrast imaging (PC). Three adjacent slices were planned to encompass the aortic valve and the aortic valve area was measured using planimetry. The two sets of complex valued images generated by the PC sequence formed three kinds of images that could be used for aortic valve area measurements: the magnitude image (PC/Mag), the modulus (PCA/M), and phase difference (PCA/P) between the two complex images, respectively. The valve area from TTE was calculated using the continuity equation. A cut-off of <1.0 cm(2) was used as a criteria for severe stenosis.

    Results: The mean area differences between the different MR acquisitions and TTE method were -0.05 ± 0.37 cm(2) (GE), -0.18 ± 0.46 cm(2) (bSSFP), 0.27 ± 0.43 cm(2) (PC/Mag), 0.15 ± 0.32 cm(2) (PCA/P), and 0.26 ± 0.27 cm(2) (PCA/M). The valve area was significantly overestimated using PCA/M that, in turn, implied a significant underestimation of the aortic valve stenosis severity compared to the assessments using TTE.

    Conclusion: The smallest area valve difference between TTE and an MR-acquisition alternative is obtained with gradient echo images. The use of PCA/M leads to significant differences in planimetry measurements of the aortic valve orifice and the gradation of the stenosis severity compared to TTE.

  • 37.
    Djemailji, Sebastian
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Bordspositioneringens betydelse för stråldos till buken samt bildkvalitet vid datortomografi med olika kilovolt – en experimentell studie med fantom2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 38.
    Djupman, Lina
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Stråldoser vid barnundersökningar med datortomografi, genomlysning och konventionell röntgen: En enkätstudie2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bakgrund: Det finns tre grundprinciper för strålskydd; berättigande, optimering och dosgränser. Utifrån detta ska röntgenundersökningarna balansera kraven på tillräcklig bildkvalitet för diagnostiseringsbara bilder och minimal patientstråldos. De dosbegrepp som används för att uppskatta stråldosen är bland annat; Dos-Area-produkt är produkten av dosen i luft och arean på strålfältet i samma position, enheten är graykvadratcentimeter (Gycm2), används vid konventionell röntgen och genomlysning. Dos-Längd-Produkten används vid datortomografi med enheten milliGraycentimeter (mGycm). Diagnostisk referensnivå (DRN) bestäms av Strålsäkerhetsmyndigheten utifrån 75%-percentilvärdet för uppmätta stråldoser för vuxna. Röntgenklinikerna ska anpassa metoderna så att de inte överskrider DRN. DRN för barnröntgen saknas.

    Syfte: Att undersöka vilka stråldoser barn fick vid röntgenundersökningar i Sverige och utifrån detta ge förslag till DRN för barn.

    Metod: Sju röntgenkliniker vid universitetssjukhus valdes och ett slumpmässigt urval av sju mindre röntgenkliniker utfördes. En pilotstudie genomfördes och utifrån denna valdes tio röntgenundersökningarna till enkäten.

    Resultat: För de flesta röntgenundersökningar ökar stråldosen med åldern och varierar inte nämnvärt mellan röntgenklinikerna. Röntgenundersökningarna som avviker från detta var; datortomografi hjärna utan kontrastmedel där stråldoserna varierar mellan 104-665 mGycm för barn i åldersgruppen noll till ett år. Konventionell röntgen av höftleden varierar stråldoserna mellan 4,0-15,8 dGycm2 för barn i åldersgruppen elva till 14 år. Genomlysningsundersökningen miktonsurethrocystografi varierade stråldoserna mellan 0,98-65 dGycm2 för barn i åldersgruppen sex till 14 år. Samtliga av dessa tre röntgenundersökningars högsta stråldosvärde ligger över det förslagna DRN.

    Konklusion: Stråldoserna vid röntgenundersökningarna varierar mellan röntgenklinikerna och ökar vanligtvis med åldern. Förslag på DRN presenteras men fler sammanställningar av stråldoser krävs eftersom underlaget i vissa fall är begränsat. 

  • 39.
    Eriksson Crommert, Martin
    et al.
    Örebro University, School of Medical Sciences.
    Unsgaard-Tøndel, Monica
    Departments of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Physiotherapy, Faculty of Health and Social Science, Norwegian University of Science and Technology, Trondheim, Norway.
    Vasseljen, Ottar
    Departments of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
    Can Sonography Be Used to Estimate Deep Abdominal Muscle Activation in Different Static Arm Positions While Standing?2017In: Journal of ultrasound in medicine, ISSN 0278-4297, E-ISSN 1550-9613, Vol. 36, no 1, p. 129-139Article in journal (Refereed)
    Abstract [en]

    Objectives: The aim of this study was to investigate whether sonography is a reliable tool for measuring deep abdominal muscle activation in different static arm positions while standing.

    Methods: Sonographic recordings were made of the transversus abdominis and obliquus internus abdominis in 4 different static arm positions that varied with regard to the postural demand and loading direction posed on the trunk. Ten nonconsecutive repetitions of each arm position were performed, and thickness measurements were made at 2 locations within each muscle. Reliability was analyzed by the generalizability theory; comparisons regarding thickness measurements were made by repeated-measures analyses of variance; and fascial sliding was analyzed by a 1-sample t test.

    Results: Averaged over all repetitions, arm positions, and the 2 measurement locations, the thickness measurements were highly reliable for both the obliquus internus abdominis and transversus abdominis. The transversus abdominis was thicker with shoulders flexed than with shoulders extended or arms above the head (P < .021) and with arms alongside the body compared with shoulders extended (P < .005). There was no thickness difference between arm positions for the obliquus internus abdominis (P = .059).

    Conclusions: The results indicate that sonographic recordings of the obliquus internus abdominis and transversus abdominis in different static arm positions while standing provide reliable measurements of muscle thickness. However, in light of previously reported electromyographic data, the results raise some concerns regarding the validity of using thickness measurements as proxies for muscle activation in positions that may induce passive muscle deformation.

  • 40.
    Eriksson, Isabella
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Knäartrosundersökning - två olika radiologiska undersökningstekniker: En observationsstudie2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Inledning

    Knäleden fungerar som en gångjärnsled och kan normalt sträckas c.a.5 grader och böjas i c.a.140 grader. Funktionen bygger mycket på stabilitet samt rörlighet, den artikulära kapseln runt knät är tunn men stabiliseras upp av omkringliggande ligament och senor med tillhörande muskler. Artros är den mest förekommande degenerativa sjukdomen i knäleden. Vid artros finns en obalans mellan uppbyggnad och nedbrytning av ledbrosket. Konventionell röntgenundersökning är standardmetod för diagnostik av knäledsartros, fyndet vid artros är fr.a. sänkt höjd av ledspringan i knät. Som standard tas 3 röntgenbilder, en frontalbild, en sidobild och en axialbild över knäskålen. För att förenkla att bilden blir korrekt inställd kan genomlysningsassistans användas.

    Syfte

    Syftet är att jämföra två olika tekniker för att undersöka knäleden vid misstanke om knäledsartros.

    Metod

    Studien genomfördes som en strukturerad observationsstudie. Författaren hade i förväg planerat vad som skulle observeras och hur det skulle registreras. Observationen genomfördes på Lindesbergs Lasarett (sjukhus A) och på Örebro Universitetssjukhus (sjukhus B) vilka använder sig av olika tekniker vid undersökning av knäledsartros.

    Resultat

    Medelvärdet för antalet exponeringar på sjukhus A var 3 bilder/patient. Medelvärdet för antalet exponerade bilder på sjukhus B var 4,2 bilder/ patient. Undersökningstiden var på sjukhus A i medeltal 9,2 minuter och på sjukhus B 11,5 minuter. Medelvärdet för patientstråldos per undersökning på sjukhus A beräknades till 0,55 Gycm2 (0,1833/bild) och på sjukhus B 0,70 Gycm2 (0,1667/bild).

    Konklusion

    Denna begränsade studie visar att antalet bilder per patient är lägre om genomlysningsassistans används för inställning för exponering av frontal- och sidoprojektion.Vidare har studien visat att genomlysningsmetoden ger kortare undersökningstider och lägre stråldos till patienterna.

  • 41.
    Farhadi, Aslan
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    En jämförande studie mellan ultraljud och datortomografi vid diagnostik av misstänkt akut appendicit.2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 42.
    Funk, Eva
    et al.
    Örebro University, School of Health Sciences.
    Anderzen-Carlsson, Agneta
    Örebro University, School of Health Sciences. Örebro University Hospital.
    Thunberg, Per
    Örebro University, School of Medical Sciences. Örebro University Hospital.
    Patient participation in MRI: patient experiences and image quality addressing breath-hold acquisitions2016In: ECR 2016 Book of Abstracts: B. Scientific Sessions and Clinical Trials in Radiology, Springer, 2016, p. S379-S379Conference paper (Other academic)
    Abstract [en]

    Purpose: To investigate two different breath-hold techniques, in terms of patient experience and image quality, and describe patients' experiences of magnetic resonance imaging.

    Methods and Materials: Thirty patients referred for an MRI of the liver conducted two separate breath-hold acquisitions in a randomised order, radiographer-directed and patient-initiated. Semi-structured interviews were held and analysed, and images were reviewed according to image quality.

    Results: The patients' general experiences of the MRI were that they felt a loss of control, and almost half of the patients seemed to prefer the self-initiated breath-hold. About 20 % of the patients preferred to hand over the responsibility to the radiographer, and for some the technique did not matter.The patients empathized in general the importance of achieving the best image quality. There were no significant differences identified between the two breath-hold techniques, in regards to image quality.

    Conclusion: The results show that self-initiated breath-hold acquisitions can be seen as a new alternative worth considering in clinical MRI since it is appreciated by the patients and give similar image quality compared to conventional breath-hold acquisitions. It also offers a possibility to achieve some control over the situation.

  • 43.
    Funk, Eva
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Anderzén-Carlsson, Agneta
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Örebro University Hospital.
    Ingverud, Per
    Department of Diagnostic Radiology, Örebro University Hospital, Örebro, Sweden.
    Leander, Anna
    Department of Diagnostic Radiology, Örebro University Hospital, Örebro, Sweden.
    Thunberg, Per
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Örebro University Hospital.
    Patient-initiated breath-holds in MRI: an alternative for reducing respiratory artifacts and improving image quality2015In: Clinical imaging, ISSN 0899-7071, E-ISSN 1873-4499, Vol. 39, no 4, p. 619-622Article in journal (Refereed)
    Abstract [en]

    Purpose: To investigate MRI image quality using two different breath-hold techniques.

    Materials and methods: Thirty patients remitted for MRI, 2D-dual gradient echo acquisition of the liver conducted two separate breath-hold acquisitions in randomized order, operator-instructed and patient-initiated. The images were reviewed by two radiologists.

    Results: There were no significant differences in image quality between the two breath-hold techniques either in overall image quality or respiratory motion artifacts. This assessment was equal and concordant for both radiologists.

    Conclusion: In terms of image quality, the patient self-initiated breath-hold was shown to be an equal alternative to conventional breath-hold imaging.

  • 44.
    Funk, Eva
    et al.
    Örebro University, School of Health Sciences.
    Thunberg, Per
    Örebro University, School of Medical Sciences. Örebro University Hospital.
    Anderzen-Carlsson, Agneta
    Örebro University, School of Health Sciences. Örebro University Hospital.
    Instructed or patient-initiated breath holds: what do the patients prefer?2013Conference paper (Other academic)
  • 45.
    Geijer, Håkan
    et al.
    Örebro University, School of Medical Sciences. Ctr Assessment Med Technol, Örebro University Hospital, Örebro, Sweden.
    Breimer, Lars H.
    Ctr Assessment Med Technol, Örebro University Hospital, Örebro, Sweden.
    Somatostatin receptor PET/CT in neuroendocrine tumours: update on systematic review and meta-analysis2013In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 40, no 11, p. 1770-1780Article, review/survey (Refereed)
    Abstract [en]

    Purpose Neuroendocrine tumours (NET) are uncommon and may be localized in many different places in the body. Traditional imaging has mainly been performed with CT and somatostatin receptor scintigraphy (SRS). Recently, it has become possible to use somatostatin receptor PET/CT (SMSR PET) instead, which might improve diagnostic quality. To evaluate the diagnostic quality of SMSR PET we performed a meta-analysis as an update of a previous study published in 2012. A literature search was performed searching MEDLINE, Embase and five other databases with a combination of the expressions "PET", "positron emission tomography", "neuroendocrine" and "NET". The search was updated to 31 December 2012. Studies were selected which evaluated the sensitivity and specificity of SMSR PET for NET in the thorax or abdomen with a study size of at least eight patients. The methodological quality of the included studies was evaluated with QUADAS-2. Eight studies fulfilled the inclusion criteria and were selected for final analysis, and 14 articles from a previous meta-analysis were added for a total of 22 articles. A total of 2,105 patients were included in the studies, an increase from 567 in the previous meta-analysis. The pooled sensitivity was 93 % (95 % CI 91 - 94 %) and specificity 96 % (95 % CI 95 - 98 %). The area under the summary ROC curve was 0.98 (95 % CI 0.95 - 1.0). In the previous meta-analysis the pooled sensitivity was 93 % (95 % CI 91 - 95 %) and specificity 91 % (95 % CI 82 - 97 %). SMSR PET has good diagnostic performance for evaluation of NET in the thorax and abdomen, better than SRS which has been the previous standard method. This meta-analysis gives further support for switching to SMSR PET.

  • 46.
    Geijer, Håkan
    et al.
    Örebro University, School of Medical Sciences. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden.
    Geijer, Mats
    Örebro University, School of Medical Sciences. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden; Department of Radiology, Skåne University Hospital, Lund, Sweden; Lund University, Lund, Sweden.
    Added value of double reading in diagnostic radiology, a systematic review2018In: Insight into Imaging, ISSN 1869-4101, E-ISSN 1869-4101, Vol. 9, no 3, p. 287-301Article, review/survey (Refereed)
    Abstract [en]

    OBJECTIVES: Double reading in diagnostic radiology can find discrepancies in the original report, but a systematic program of double reading is resource consuming. There are conflicting opinions on the value of double reading. The purpose of the current study was to perform a systematic review on the value of double reading.

    METHODS: A systematic review was performed to find studies calculating the rate of misses and overcalls with the aim of establishing the added value of double reading by human observers.

    RESULTS: The literature search resulted in 1610 hits. After abstract and full-text reading, 46 articles were selected for analysis. The rate of discrepancy varied from 0.4 to 22% depending on study setting. Double reading by a sub-specialist, in general, led to high rates of changed reports.

    CONCLUSIONS: The systematic review found rather low discrepancy rates. The benefit of double reading must be balanced by the considerable number of working hours a systematic double-reading scheme requires. A more profitable scheme might be to use systematic double reading for selected, high-risk examination types. A second conclusion is that there seems to be a value of sub-specialisation for increased report quality. A consequent implementation of this would have far-reaching organisational effects.

    KEY POINTS: • In double reading, two or more radiologists read the same images. • A systematic literature review was performed. • The discrepancy rates varied from 0.4 to 22% in various studies. • Double reading by sub-specialists found high discrepancy rates.

  • 47.
    Geijer, Mats
    et al.
    Örebro University, School of Medical Sciences. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden.
    Gunnlaugsson, Eirikur
    Department of Medical Imaging and Physiology, Lund University, Lund, Sweden; Skåne University Hospital, Lund, Sweden.
    Götestrand, Simon
    Department of Medical Imaging and Physiology, Lund University, Lund, Sweden; Skåne University Hospital, Lund, Sweden.
    Weber, Lars
    Department of Radiation Physics, Skåne University Hospital, Lund, Sweden.
    Geijer, Håkan
    Örebro University, School of Health Sciences. Department of Radiology.
    Tomosynthesis of the thoracic spine: added value in diagnosing vertebral fractures in the elderly2017In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 27, no 2, p. 491-497Article in journal (Refereed)
    Abstract [en]

    Objectives: Thoracic spine radiography becomes more difficult with age. Tomosynthesis is a low-dose tomographic extension of radiography which may facilitate thoracic spine evaluation. This study assessed the added value of tomosynthesis in imaging of the thoracic spine in the elderly.

    Methods: Four observers compared the image quality of 50 consecutive thoracic spine radiography and tomosynthesis data sets from 48 patients (median age 67 years, range 55-92 years) on a number of image quality criteria. Observer variation was determined by free-marginal multirater kappa. The conversion factor and effective dose were determined from the dose-area product values.

    Results: For all observers significantly more vertebrae were seen with tomosynthesis than with radiography (mean 12.4/9.3, P < 0.001) as well as significantly more fractures (mean 0.9/0.7, P = 0.017). The image quality score for tomosynthesis was significantly higher than for radiography, for all evaluated structures. Tomosynthesis took longer to evaluate than radiography. Despite this, all observers scored a clear preference for tomosynthesis. Observer agreement was substantial (mean κ = 0.73, range 0.51-0.94). The calibration or conversion factor was 0.11 mSv/(Gy cm(2)) for the combined examination. The resulting effective dose was 0.87 mSv.

    Conclusion: Tomosynthesis can increase the detection rate of thoracic vertebral fractures in the elderly, at low added radiation dose.

    KEY POINTS:• Tomosynthesis helps evaluate the thoracic spine in the elderly. • Observer agreement for thoracic spine tomosynthesis was substantial (mean κ = 0.73). • Significantly more vertebrae and significantly more fractures were seen with tomosynthesis. • Tomosynthesis took longer to evaluate than radiography. • There was a clear preference among all observers for tomosynthesis over radiography.

  • 48.
    Geijer, Mats
    et al.
    Örebro University, School of Medical Sciences. Örebro University Hospital. Department of Radiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden .
    Jureus, Jan
    Department of Orthopedic Surgery, Skåne University Hospital and Lund University, Lund, Sweden.
    Hanni, Mari
    Department of Radiology, Akademiska Hospital, Uppsala, Sweden.
    Shalabi, Adel
    Department of Radiology, Akademiska Hospital, Uppsala, Sweden.
    MR appearance of the temporal evolution and resolution of spontaneous osteonecrosis of the knee: a case report2017In: Acta Radiologica Open, E-ISSN 2058-4601, Vol. 6, no 2Article in journal (Refereed)
    Abstract [en]

    Spontaneous osteonecrosis of the knee (SONK) is a feared condition of unknown cause, in its classic form appearing in the medial femoral condyle in middle-aged or elderly subjects. Diagnosis with radiography is notoriously difficult with a long latency before typical changes appear. Magnetic resonance imaging (MRI) is regarded as a diagnostic tool with the possibility to give an earlier diagnosis with improved chances for treatment. However, also with MRI there may be an initial diagnostic blind spot before typical changes appear. Little is known about the temporal evolution of the MRI changes. In the current case report, a case of SONK is reported where serial imaging with MRI was performed, from initial symptoms to eventual resolution after almost three years.

  • 49.
    Geijer, Mats
    et al.
    Örebro University, School of Medical Sciences. Department of Radiology, Faculty of Health and Medical Sciences, Örebro University, Örebro, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden.
    Laurin, Olof
    Slogstorp, Björkdala, Löberöd, Sweden.
    Johnsson, Ragnar
    Department of Orthopedic surgery, Skåne University Hospital, Lund, Sweden; Lund University, Lund, Sweden.
    Laurin, Sven
    Department of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden; Lund University, Lund, Sweden.
    A computer-assisted systematic quality monitoring method for cervical hip fracture radiography2016In: Acta Radiologica Open, ISSN 2058-4601, Vol. 5, no 12Article in journal (Refereed)
    Abstract [en]

    Background: A thorough quality analysis of radiologic performance is cumbersome. Instead, the prevalence of missed cervical hip fractures might be used as a quality indicator.

    Purpose: To validate a computer-based quality study of cervical hip fracture radiography.

    Material and Methods: True and false negative and positive hip trauma radiography during 6 years was assessed manually. Patients with two or more radiologic hip examinations before surgery were selected by computer analysis of the databases. The first of two preoperative examinations might constitute a missed fracture. These cases were reviewed.

    Results: Out of 1621 cervical hip fractures, manual perusal found 51 (3.1%) false negative radiographic diagnoses. Among approximately 14,000 radiographic hip examinations, there were 27 (0.2%) false positive diagnoses. Fifty-seven percent of false negative reports were occult fractures, the other diagnostic mistakes. There were no significant differences over the years. Diagnostic sensitivity was 96.9% and specificity 99.8%. Computer-assisted analysis with a time interval of at least 120 days between the first and the second radiographic examination discovered 39 of the 51 false negative reports.

    Conclusion: Cervical hip trauma radiography has high sensitivity and specificity. With computer-assisted analysis, 76% of false negative reports were found.

  • 50.
    Geijer, Mats
    et al.
    Örebro University Hospital. Örebro University, School of Medical Sciences. Department of Radiology, Örebro University Hospital, Örebro, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden.
    Rundgren, Gustav
    Department of Clinical Sciences, Lund University, Lund, Sweden.
    Weber, Lars
    Department of Clinical Sciences, Lund University, Lund, Sweden; Department of Radiation Physics, Skåne University Hospital, Lund, Sweden.
    Flivik, Gunnar
    Department of Clinical Sciences, Lund University, Lund, Sweden; Department of Orthopedics, Skåne University Hospital, Lund, Sweden.
    Effective dose in low-dose CT compared with radiography for templating of total hip arthroplasty2017In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 58, no 10, p. 1276-1282Article in journal (Refereed)
    Abstract [en]

    Background: Recently, total hip arthroplasty (THA) has come to focus on restoration of individual anatomy including femoral neck anteversion and global offset (femoral and acetabular offset). Three-dimensional (3D) computed tomography (CT) data could provide a better basis for preoperative templating. The use of CT has been hampered by high radiation dose.

    Purpose: To evaluate the effective dose used in pelvis and hip CT for THA templating.

    Material and Methods: CT data from two clinical trials of THA were evaluated for CT scan length and volume CT dose index (CTDIvol). The effective doses from hip-knee-ankle CT and pelvis and hip radiography were compared. Conversion factors for effective dose for radiography were calculated using the PCXMC software.

    Results: A reduced dose CT protocol for pelvis imaging gave a substantial dose reduction compared with standard CT, while maintaining sufficient image quality. Between the two clinical trials there was a significant reduction in effective CT dose corresponding to changes in the CT protocol (P<0.01). The CT dose for the latter group was similar to, but nevertheless significantly higher than for, radiography (P<0.01). However, in the latter group the theoretical minimum dose for CT, using the minimum scan length required by the templating software, was equal to the dose from radiography.

    Conclusion: Although the CT dose remained higher than for radiography, potential reductions in scan length could reduce the dose further so that CTwould have a comparable level of risk to radiography with the added benefit of 3D templating.

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