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  • 51.
    Chew, Michelle
    et al.
    University of Aarhus Denamrk.
    Brandberg, Joakim
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Sloth, Erik
    Aarhus University Hospital Aarhus Denmark.
    Ask, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Janerot-Sjöberg, Birgitta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Non-invasive cardiac output measurement using colour Doppler ultrasound - the SIVV approach1999In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 114, p. 91-92Article in journal (Refereed)
  • 52.
    Dahlin, Lars-Göran
    et al.
    Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    Eveling-Barbier, C.
    Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Nylander, Eva
    Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Rutberg, Hans
    Östergötlands Läns Landsting, Heart Centre.
    Svedjeholm, Rolf
    Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    Vectorcardiography is Superior to Conventional ECG for Detection of Myocardial Injury after Coronary Surgery2001In: Scandinavian Cardiovascular Journal, ISSN 1401-7431, E-ISSN 1651-2006, Vol. 35, no 2, p. 125-128Article in journal (Refereed)
    Abstract [en]

    Objective - The reliability of conventional scalar ECG for diagnosis of perioperative myocardial infarction (PMI) in cardiac surgery has been questioned. For the diagnosis of myocardial infarction in general vectorcardiography (VCG) is superior to ECG. Therefore, the usefulness of conventional VCG and computerized analysis of spatial VCG changes for diagnosis of PMI were studied.

    Design - VCG registrations were obtained from 218 patients undergoing coronary surgery. The spatial QRS vector loop area of each VCG registration was calculated and the loop area before surgery compared with the loop area after surgery. Conventional VCG criteria for myocardial infarction and set values for loop area reduction were related to sustained elevation of plasma troponin-T and clinical course.

    Results - Both conventional VCG criteria and spatial changes translated better than Q-waves on scalar ECG into elevation of biochemical markers of myocardial injury and impaired clinical course.

    Conclusion - VCG appears superior to conventional ECG as regards detection of myocardial injury in coronary surgery. Computerized programs have facilitated the registration and the interpretation of VCG and this methodology deserves further evaluation in cardiac surgery.

  • 53.
    Dahlin, Lars-Göran
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Thoracic Surgery. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Kågedahl, Bertil
    Nylander, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Olin, Christian
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Thoracic Surgery. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Rutberg, Hans
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Svedjeholm, Rolf
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Thoracic Surgery. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Unspecific elevation of plasma troponin-T after coronary surgery. Abstract 17th Annual meeting EACTA, 2002 June 12-15, Dublin Ireland2002In: EACTA Abstracts 2002,2002, 2002Conference paper (Refereed)
  • 54.
    Dahlin, Lars-Göran
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Thoracic Surgery. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Kågedal, Bertil
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Clinical Chemistry. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Chemistry.
    Nylander, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Olin, Christian
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Thoracic Surgery.
    Rutberg, Hans
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Svedjeholm, Rolf
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Thoracic Surgery. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Unspecific elevation of plasma troponin-T and CK-MB after coronary surgery2003In: Scandinavian Cardiovascular Journal, ISSN 1401-7431, E-ISSN 1651-2006, Vol. 37, no 5, p. 283-287Article in journal (Refereed)
    Abstract [en]

    Objective - Biochemical markers of myocardial injury are frequently elevated after cardiac surgery. It is generally accepted that release unrelated to permanent myocardial damage explains a proportion of these elevations. However, little is known about the magnitude and temporal characteristics of this diagnostic noise. One way to address this issue would be to study a group without permanent myocardial injury. Design - The unique release kinetics of troponin-T (permanent myocardial injury causes a sustained release of structurally bound troponin) were used to identify patients with no or minimal permanent myocardial injury. Blood was sampled from patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) before surgery, 3 and 8 h after unclamping the aorta, and each morning until postoperative day 4, for analysis of enzymes and troponin-T. From 302 consecutive patients a subgroup was identified that fulfilled the following criteria: (a) normalized troponin-T levels =postoperative day 4, (b) no ECG changes indicating myocardial injury. Results - Seventy-seven patients fulfilled the criteria above and in this subgroup troponin-T (2.08 ▒ 1.42 ╡g/ 1, range 0.35-8.99 ╡g/l) peaked at the 3 h recording and creatine kinase monobasic (CK-MB) (28.6 ▒ 11.3 ╡g/l, range 11.9-86.0 ╡g/l) peaked at the 8 h recording after unclamping the aorta. Conclusion - Substantial early elevations of plasma CK-MB and troponin-T occurred in patients with no or minimal permanent myocardial injury after CABG. Unspecific release was most pronounced during the timeframe that is usually studied to evaluate myocardial protective strategies or to compare revascularization procedures.

  • 55.
    Dahlén, Elsa M
    et al.
    Linköping University, Department of Medicine and Health Sciences, General Practice. Linköping University, Faculty of Health Sciences.
    Länne, Toste
    Linköping University, Department of Medicine and Health Sciences, Physiology . Linköping University, Department of Medicine and Health Sciences, Vascular surgery . Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery. Linköping University, Faculty of Health Sciences.
    Engvall, Jan
    Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences.
    Lindström, T
    Linköping University, Department of Medicine and Health Sciences, Internal Medicine . Östergötlands Läns Landsting, Centre for Medicine, Department of Endocrinology and Gastroenterology UHL. Linköping University, Faculty of Health Sciences.
    Grodzinsky, Ewa
    Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland. Linköping University, Department of Medicine and Health Sciences, General Practice. Linköping University, Faculty of Health Sciences.
    Nyström, Fredrik
    Linköping University, Department of Medicine and Health Sciences, Internal Medicine . Östergötlands Läns Landsting, Centre for Medicine, Department of Endocrinology and Gastroenterology UHL. Linköping University, Faculty of Health Sciences.
    Östgren, Carl Johan
    Linköping University, Department of Medicine and Health Sciences, General Practice. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in the West of Östergötland, West County Primary Health Care.
    Complications Carotid intima-media thickness and apolipoprotein B/apolipoprotein A-I ratio in middle-aged patients with Type 2 diabetes2009In: Diabetic Medicine, ISSN 0742-3071, E-ISSN 1464-5491, Vol. 26, no 4, p. 384-390Article in journal (Refereed)
    Abstract [en]

    AIMS: To explore the association between carotid intima-media thickness (IMT) and the apolipoprotein B (apoB)/apolipoprotein A-I (apoA-I) ratio compared with conventional lipids in middle-aged patients with Type 2 diabetes. METHODS: We analysed data from 247 patients with Type 2 diabetes, aged 55-66 years, in the Cardiovascular Risk factors in Patients with Diabetes-a Prospective study in Primary care (CARDIPP-1) study. Primary care nurses measured blood pressure and anthropometric characteristics. Blood samples were taken for laboratory analyses. The carotid IMT was determined by ultrasonography at the University Hospital in Linköping and at the County Hospital Ryhov, Jönköping, Sweden. RESULTS: The ApoB/apoA-I ratio (r = 0.207, P = 0.001), apoB (r = 0.166, P = 0.009) and non-high-density lipoprotein cholesterol (non-HDL-c) (r = 0.129, P = 0.046) correlated with IMT. Conventional lipids, high-sensitivity C-reactive protein (hsCRP), glycated haemoglobin (HbA(1c)) and systolic blood pressure were not significantly correlated to IMT. A stepwise logistic regression analysis was conducted with IMT as the dependent variable and the apoB/apoA-I ratio, HbA(1c), hsCRP, low-density lipoprotein cholesterol (LDL-c), total cholesterol, non-HDL-c and treatment with statins as independent variables. Following adjustment for age and gender, only the apoB/apoA-I ratio remained significantly associated with IMT (odds ratio 4.3, 95% confidence intervals 1.7-10.8, P = 0.002). CONCLUSIONS: We conclude that there was a significant association between the apoB/apoA-I ratio and IMT in middle-aged patients with Type 2 diabetes. The association was independent of conventional lipids, hsCRP, glycaemic control and use of statins.

  • 56.
    Dahlén, Elsa M
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Östergötlands Läns Landsting, Local Health Care Services in West Östergötland.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Lindström, Torbjörn
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    Grodzinsky, Ewa
    Linköping University, Department of Social and Welfare Studies, Division of Health, Activity and Care. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in West Östergötland, Research & Development Unit in Local Health Care.
    Nyström, Fredrik
    Östergötlands Läns Landsting, Heart and Medicine Center, Department of Endocrinology and Gastroenterology UHL. Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    Östgren, Carl Johan
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in West Östergötland.
    Carotid intima-media thickness and apolipoprotein B/apolipoprotein A-I ratio in middle-aged patients with Type 2 diabetes2009In: Diabetic Medicine, ISSN 0742-3071, E-ISSN 1464-5491, Vol. 26, no 4, p. 384-390Article in journal (Refereed)
    Abstract [en]

    Aims To explore the association between carotid intima-media thickness (IMT) and the apolipoprotein B (apoB)/apolipoprotein A-I (apoA-I) ratio compared with conventional lipids in middle-aged patients with Type 2 diabetes.

    Methods We analysed data from 247 patients with Type 2 diabetes, aged 55–66 years, in the Cardiovascular Risk factors in Patients with Diabetes—a Prospective study in Primary care (CARDIPP-1) study. Primary care nurses measured blood pressure and anthropometric characteristics. Blood samples were taken for laboratory analyses. The carotid IMT was determined by ultrasonography at the University Hospital in Linköping and at the County Hospital Ryhov, Jönköping, Sweden.

    Results The ApoB/apoA-I ratio (r = 0.207, P = 0.001), apoB (r = 0.166, P = 0.009) and non-high-density lipoprotein cholesterol (non-HDL-c) (r = 0.129, P = 0.046) correlated with IMT. Conventional lipids, high-sensitivity C-reactive protein (hsCRP), glycated haemoglobin (HbA1c) and systolic blood pressure were not significantly correlated to IMT. A stepwise logistic regression analysis was conducted with IMT as the dependent variable and the apoB/apoA-I ratio, HbA1c, hsCRP, low-density lipoprotein cholesterol (LDL-c), total cholesterol, non-HDL-c and treatment with statins as independent variables. Following adjustment for age and gender, only the apoB/apoA-I ratio remained significantly associated with IMT (odds ratio 4.3, 95% confidence intervals 1.7–10.8, P = 0.002).

    Conclusions We conclude that there was a significant association between the apoB/apoA-I ratio and IMT in middle-aged patients with Type 2 diabetes. The association was independent of conventional lipids, hsCRP, glycaemic control and use of statins.

  • 57.
    Davidsson, Anette
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Exhaled Breath Condensate in Obstructive Lung Diseases: A Methodological study2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Asthma and chronic obstructive pulmonary disease (COPD) are two common inflammatory airway diseases characterized by airway inflammation and mucus hypersecretion. Prediction of the outcome of these diseases may not be performed and the need for non-invasive diagnostic tools capable of identifying inflammation in asthma and COPD becomes therefore obvious. Validation, sensitivity and specificity of most non-invasive methods to detect and monitor inflammatory responses in airways are poor and there is a great need to identify and standardize less invasive, or non-invasive methods for investigation of airway inflammation.

    Epithelial lining fluid (ELF) covers the airway surface and contains soluble and insoluble inflammatory cell products and plasma proteins originating and passively transferred from the underlying tissue. Airborne aerosol particles containing ELF saturated with water may be recovered in exhaled air by allowing the air to pass a cold surface, creating exhaled breath condensate (EBC). EBC may then be analysed for various components of interest.

    The aims of this thesis were (1) to explore whether a certain profile of inflammatory cell markers in EBC, saliva or serum may be identified in patients with allergic asthma or COPD, (2) to evaluate the efficacy and reproducibility of a measurable marker in EBC using either of the two condensers ECoScreen or RTube and (3) to evaluate the value of chlorine concentrations in EBC as well as reproducibility of assessments of certain compounds in EBC.

    Material and methods: Thirty-six patients with asthma, 49 smokers or ex-smokers and 25 healthy volunteers participated in three clinical studies. In addition, efficacy, reproducibility and comparison of the two condensers were studied in an ex vivo set up using aerosols of solutions of saline, myeloperoxidase (MPO) or human neutrophil lipocalin (HNL). Aerosol boluses were transferred by means of a servo ventilator to either of the two condensers. Concentrations of chlorine (presumed to be a marker of mucous secretion) in EBC or saliva were analyzed by means of a sensitive coulometric technique (AOX). The inflammatory cell markers histamine, MPO, HNL, lysozyme, cysteinyl-leukotrienes (CysLT) and eosinophil cationic protein (ECP) were analysed in EBC, saliva and/or serum by means of ELISA, RIA, EIA or immunochemical fluorescence methods, respectively. Lung function tests, including diffusion capacity were measured by standard techniques according to clinical routines.

    Results and Conclusions: Chlorine measurements served as the main tool in our tests and intra-assay variability <10% was recorded. However, flow dependency, temperature dependency, substance dependency and concentration dependency characterized yields of EBC. Despite acceptable analytical precision, low concentration levels of inflammation markers, biological variability and occasionally contamination with saliva mean that the feasibility of the EBC method is limited. Despite biological variability, concentrations of chlorine in EBC were significantly higher during than after a mild pollen season, suggesting that chlorine concentrations in EBC are a sensitive marker of allergic airway inflammation. A vast number of confounding factors made interpretations of EBC data obtained from COPD and non-COPD patients difficult and traditional diagnostic tools, such as diffusion capacity (DLCO) and serum lysozyme appeared to best discriminate between COPD and non-COPD.

    List of papers
    1. Quantitative Assessment and Repeatability of Chlorine in Exhaled Breath Condensate: Comparison of Two Types of Condensators
    Open this publication in new window or tab >>Quantitative Assessment and Repeatability of Chlorine in Exhaled Breath Condensate: Comparison of Two Types of Condensators
    2005 (English)In: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 72, no 5, p. 529-536Article in journal (Refereed) Published
    Abstract [en]

    Background: Airway condition is presumably reflected in epithelial lining fluid (ELF). Exhaled breath condensate (EBC) has been used as a surrogate marker of the composition of ELF.

    Objectives: This study aimed at assessing the technical repeatability of chlorine measurements in EBC and comparing two separate condensators (Ecoscreen® and R Tube) regarding recovery and repeatability. Furthermore, the association between condensate recoveries and variations in the airway status were scrutinized.

    Methods: EBC was collected using two condensators from 10 healthy volunteers. In addition, 13 asthmatic patients produced EBC with or without an added resistance of 5 cm H2O (Res5), applied to the outflow tract of Ecoscreen. All tests were done in random order. Chlorine levels (analyzed by a coulometric technique) in EBC served as a tool for investigation.

    Results: Chlorine was measurable in all samples. The coefficient of repeatability of chlorine measurements was <10%. Chlorine levels were higher in EBC obtained from R Tube (p < 0.001), and differences in recoveries and variability in chlorine levels were presumably related to technical differences in the condensators and not to the repeatability of chlorine measurements per se. Air-flow-dependent chlorine levels were obtained from healthy volunteers. Application of Res5, recruiting additional alveoli, resulted in increased recovery of the EBC volume, but not of chlorine, from those that had the most pronounced airway obstruction (p = 0.05).

    Conclusion: We conclude that by employing a sensitive analysis technique, chlorine is repeatedly measurable in EBC. We suggest that the bulk of chlorine in EBC originates from large airways and not from the alveolar area. Both condensators were comparable regarding repeatability but differed regarding chlorine recover

    Keywords
    Asthma, Chlorine, Exhaled breath condensate, Repeatability, Volunteers
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-16289 (URN)10.1159/000087679 (DOI)
    Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2017-12-14Bibliographically approved
    2. Chlorine in Breath Condensate: A Measure of Airway Affection in Pollinosis?
    Open this publication in new window or tab >>Chlorine in Breath Condensate: A Measure of Airway Affection in Pollinosis?
    2007 (English)In: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 74, no 2, p. 184-191Article in journal (Refereed) Published
    Abstract [en]

    Background: Infiltration of inflammatory cells in bronchial mucosa and glandular hypersecretion are hallmarks of asthma. It has been postulated that exhaled breath condensate (EBC) mirrors events in epithelial lining fluid of airways, such as presence of local inflammation as well as glandular hypersecretion. It is also well known that eosinophil cationic protein (ECP) and cysteinyl-leukotrienes (cys-LT) are released by circulating inflammatory cells when triggered by antigen stimulation in asthma patients.

    Objectives: The aim of this study was to evaluate whether chlorine and/or cys-LT in EBC would reflect changes of exposure of airborne pollen in patients with asthma.

    Methods: EBC and serum were collected from 23 patients with allergic asthma during a pollen season and repeated 5 months later during a period with no aeroallergens. Chlorine was measured by means of a sensitive coulometric technique and cys-LT by an EIA technique. Serum ECP was measured and lung function tests were performed and symptoms noted during both occasions.

    Results: Significantly higher concentrations of chlorine in EBC (p = 0.007) and ECP in serum (p = 0.003) were found during the pollen season compared to post-season. Chlorine levels tended to be higher in patients who reported of chest symptoms compared to those who denied symptoms during the pollen season (p = 0.06). Areas under the receiver-operated characteristic curves (AUCROC) were compared and similar discriminative power to identify exacerbations of asthma was recorded by chlorine in EBC (range 0.67-0.78) and ECP in serum (range 0.64-0.78).

    Conclusion: It is concluded that chlorine in EBC and ECP in serum decreased significantly post-season, and this is suggested to mirror the decrement in airborne antigen. It is furthermore proposed that chlorine in EBC and ECP in serum tend to have a similar capacity to identify seasonal variations in airborne pollen in patients with asthma.

    Place, publisher, year, edition, pages
    Karger, 2007
    Keywords
    Pollen season, Allergic asthma, Exhaled breath condensate, Serum eosinophil cationic protein, Chlorine
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-16291 (URN)10.1159/000091300 (DOI)000244565600010 ()
    Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2017-12-14Bibliographically approved
    3. Efficacy of Two Breath Condensers: An in Vitro Comparative Study
    Open this publication in new window or tab >>Efficacy of Two Breath Condensers: An in Vitro Comparative Study
    2008 (English)Article in journal (Refereed) Submitted
    Abstract [en]

    Examination of exhaled breath condensate (EBC) has been suggested to give information about inflammatory airway diseases.

    The aim of the present study was to compare efficacy and variability in gain of two commercially available condensers, ECoScreen® [E] and RTube [R] in an in vitro experimental set up.

    Methods: Test-fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin (BSA) were nebulized. The aerosol was intermittently driven forward by a servoventilator fed by room tempered air, to reach the condenser. Two different concentrations of saline were also dispensed via the same equipment. Analyses of MPO, HNL and chlorine were done by means of ELISA, RIA or a modified adsorbed organic halogen technique (AOX), respectively.

    Results: Significantly higher volumes were recovered by ECoScreen than by RTube during 20-minutes experiments (p<0.001) but not in ten-minute experiments (p>0.05). Based on changes of source concentrations in the nebulizer cup, resulting from nebulization per se, recoveries of HNL tended to be higher by E than by R (p<0.05). In contrast there were no significant differences between condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds and of similar degree for both condensers, despite acceptable inter-assay coefficients of variations of all analyses.

    Conclusion: Condensing efficacy tended to be larger using E than R but there was a large variability in results from both condensers. Individual biomolecules may have their specific characteristics, and this must be taken into consideration when planning studies on EBC. We suggest that further methodological studies of the EBC method are warranted.

    Keywords
    Chlorine, HNL, MPO, Exhaled Breath Condensate, efficacy
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-16292 (URN)
    Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2009-08-17Bibliographically approved
    4. Can we predict development of COPD?
    Open this publication in new window or tab >>Can we predict development of COPD?
    2008 (English)Article in journal (Refereed) Submitted
    Abstract [en]

    Background: Cigarette smoking is one of the main causes of chronic obstructive pulmonarydisease (COPD). Chronic inflammation of airways may start years before manifestation ofclinical symptoms, thus early identification of smokers at risk to develop COPD is crucial.Objectives: To evaluate if a single breath test for diffusion capacity (DLCO) or concentrationsof certain biomarkers in exhaled breath condensate (EBC), saliva or serum could identifysubjects with COPD or non-COPD smokers and ex-smokers supposed to be at risk to developCOPD, as suggested by rapid decline of forced expiratory volume in one second (FEV1) during afive year period.

    Methods: Twenty-nine symptom free smokers/ex-smokers, 16 smokers/ex-smokers with COPDand 19 matched healthy non-smoking volunteers were studied by means of spirometry, DLCO,and analyses of EBC, saliva and serum [chlorine, lysozyme, eosinophil cationic protein (ECP)and myeloperoxidase (MPO)]. Area under a receiver operated curve (AUCROC) was used toassess sensitivity and specificity of measurements to identify manifest or risk to get COPD.

    Results: Only DLCO could identify subjects with COPD or risk to develop COPD, as judged byAUCROC (0.85 or 0.75, respectively). Lower DLCO (p=0.003) and higher serum concentrationsof lysozyme (p=0.011) were recorded in those with COPD than non-COPD subjects.Furthermore, concentration of chlorine was higher in EBC from COPD subjects than fromhealthy volunteers (p<0.05). Except for chlorine, none of the remaining biomarkers weredetected in EBC and there was a vast variability of concentrations of biomarkers in saliva.

    Conclusion: DLCO was the most effective discriminator of COPD and rapid decline of lungfunction. Serum concentration of lysozyme was the second strongest discriminator, confirmingprevious findings on involvement of neutrophils in the disease process. The use of EBC as a toolto measure exhaled biomarkers involved in COPD is dubious due to large variability and lowconcentrations of markers in EBC.

    Keywords
    Exhaled Breath Condensate, serum, DLCO, COPD, lysozyme and chlorine
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-16293 (URN)
    Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2009-09-18Bibliographically approved
  • 58.
    Davidsson, Anette
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Histamine release from blood cells and serum ECP in patients with asthma, during and after a mild pollen season.2004In: The European Histamine Research Society, Köln, 2004, p. na-naConference paper (Refereed)
  • 59.
    Davidsson, Anette
    et al.
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Naidu-Sjöswärd, Kerstin
    Linköping University, Department of Medicine and Health Sciences, Anesthesiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthesiology and Surgical Centre, Department of Intensive Care UHL.
    Lundman, Lena
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Schmekel, Birgitta
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Quantitative Assessment and Repeatability of Chlorine in Exhaled Breath Condensate: Comparison of Two Types of Condensators2005In: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 72, no 5, p. 529-536Article in journal (Refereed)
    Abstract [en]

    Background: Airway condition is presumably reflected in epithelial lining fluid (ELF). Exhaled breath condensate (EBC) has been used as a surrogate marker of the composition of ELF.

    Objectives: This study aimed at assessing the technical repeatability of chlorine measurements in EBC and comparing two separate condensators (Ecoscreen® and R Tube) regarding recovery and repeatability. Furthermore, the association between condensate recoveries and variations in the airway status were scrutinized.

    Methods: EBC was collected using two condensators from 10 healthy volunteers. In addition, 13 asthmatic patients produced EBC with or without an added resistance of 5 cm H2O (Res5), applied to the outflow tract of Ecoscreen. All tests were done in random order. Chlorine levels (analyzed by a coulometric technique) in EBC served as a tool for investigation.

    Results: Chlorine was measurable in all samples. The coefficient of repeatability of chlorine measurements was <10%. Chlorine levels were higher in EBC obtained from R Tube (p < 0.001), and differences in recoveries and variability in chlorine levels were presumably related to technical differences in the condensators and not to the repeatability of chlorine measurements per se. Air-flow-dependent chlorine levels were obtained from healthy volunteers. Application of Res5, recruiting additional alveoli, resulted in increased recovery of the EBC volume, but not of chlorine, from those that had the most pronounced airway obstruction (p = 0.05).

    Conclusion: We conclude that by employing a sensitive analysis technique, chlorine is repeatedly measurable in EBC. We suggest that the bulk of chlorine in EBC originates from large airways and not from the alveolar area. Both condensators were comparable regarding repeatability but differed regarding chlorine recover

  • 60.
    Davidsson, Anette
    et al.
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Schmekel, Birgitta
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Efficacy of two breath condensers2010In: Journal of clinical laboratory analysis (Print), ISSN 0887-8013, E-ISSN 1098-2825, Vol. 24, no 4, p. 219-223Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Examination of Exhaled Breath Condensate has been suggested to give information about inflammatory airway diseases. OBJECTIVES: The aim was to compare efficacy and variability in gain of two commercially available exhaled breath condensers, ECoScreen and RTube in an in vitro set up. METHODS: Test fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin were nebulized and aerosols were transferred by a servo ventilator to either of the two condensers. Analyses of MPO, HNL, or chlorine were done by means of ELISA, RIA, or a modified adsorbed organic halogen technique (AOX), respectively. RESULTS: Recoveries of HNL were higher when using ECoScreen than RTube (Pandlt;0.05). In contrast, there were no significant differences between the two condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds. CONCLUSION: Variability in gain was large and ECoScreen was more efficacious then RTube in condensing the tested solutes of HNL, but not those of MPO or chlorine.

  • 61.
    Davidsson, Anette
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Schmekel, Birgitta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Histamine release from blood cells and serum ECP in patients with asthma, during and after a mild pollen season2005In: Inflammation Research, ISSN 1023-3830, E-ISSN 1420-908X, Vol. 54, p. S76-S77Article in journal (Refereed)
  • 62.
    Davidsson, Anette
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Stratelis, Georgios
    Linköping University, Department of Medicine and Health Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in the West of Östergötland, Primary Health Care Centres.
    Acevedo, F.
    Karolinska Institutet.
    Schmekel, Birgitta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Can we predict development of COPD?2008Article in journal (Refereed)
    Abstract [en]

    Background: Cigarette smoking is one of the main causes of chronic obstructive pulmonarydisease (COPD). Chronic inflammation of airways may start years before manifestation ofclinical symptoms, thus early identification of smokers at risk to develop COPD is crucial.Objectives: To evaluate if a single breath test for diffusion capacity (DLCO) or concentrationsof certain biomarkers in exhaled breath condensate (EBC), saliva or serum could identifysubjects with COPD or non-COPD smokers and ex-smokers supposed to be at risk to developCOPD, as suggested by rapid decline of forced expiratory volume in one second (FEV1) during afive year period.

    Methods: Twenty-nine symptom free smokers/ex-smokers, 16 smokers/ex-smokers with COPDand 19 matched healthy non-smoking volunteers were studied by means of spirometry, DLCO,and analyses of EBC, saliva and serum [chlorine, lysozyme, eosinophil cationic protein (ECP)and myeloperoxidase (MPO)]. Area under a receiver operated curve (AUCROC) was used toassess sensitivity and specificity of measurements to identify manifest or risk to get COPD.

    Results: Only DLCO could identify subjects with COPD or risk to develop COPD, as judged byAUCROC (0.85 or 0.75, respectively). Lower DLCO (p=0.003) and higher serum concentrationsof lysozyme (p=0.011) were recorded in those with COPD than non-COPD subjects.Furthermore, concentration of chlorine was higher in EBC from COPD subjects than fromhealthy volunteers (p<0.05). Except for chlorine, none of the remaining biomarkers weredetected in EBC and there was a vast variability of concentrations of biomarkers in saliva.

    Conclusion: DLCO was the most effective discriminator of COPD and rapid decline of lungfunction. Serum concentration of lysozyme was the second strongest discriminator, confirmingprevious findings on involvement of neutrophils in the disease process. The use of EBC as a toolto measure exhaled biomarkers involved in COPD is dubious due to large variability and lowconcentrations of markers in EBC.

  • 63.
    Davidsson, Anette
    et al.
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Söderström, Mats
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Naidu Sjöswärd, Kerstin
    Linköping University, Department of Medical and Health Sciences, Anesthesiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthesiology and Surgical Centre, Department of Intensive Care UHL.
    Schmekel, Birgitta
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Chlorine in Breath Condensate: A Measure of Airway Affection in Pollinosis?2007In: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 74, no 2, p. 184-191Article in journal (Refereed)
    Abstract [en]

    Background: Infiltration of inflammatory cells in bronchial mucosa and glandular hypersecretion are hallmarks of asthma. It has been postulated that exhaled breath condensate (EBC) mirrors events in epithelial lining fluid of airways, such as presence of local inflammation as well as glandular hypersecretion. It is also well known that eosinophil cationic protein (ECP) and cysteinyl-leukotrienes (cys-LT) are released by circulating inflammatory cells when triggered by antigen stimulation in asthma patients.

    Objectives: The aim of this study was to evaluate whether chlorine and/or cys-LT in EBC would reflect changes of exposure of airborne pollen in patients with asthma.

    Methods: EBC and serum were collected from 23 patients with allergic asthma during a pollen season and repeated 5 months later during a period with no aeroallergens. Chlorine was measured by means of a sensitive coulometric technique and cys-LT by an EIA technique. Serum ECP was measured and lung function tests were performed and symptoms noted during both occasions.

    Results: Significantly higher concentrations of chlorine in EBC (p = 0.007) and ECP in serum (p = 0.003) were found during the pollen season compared to post-season. Chlorine levels tended to be higher in patients who reported of chest symptoms compared to those who denied symptoms during the pollen season (p = 0.06). Areas under the receiver-operated characteristic curves (AUCROC) were compared and similar discriminative power to identify exacerbations of asthma was recorded by chlorine in EBC (range 0.67-0.78) and ECP in serum (range 0.64-0.78).

    Conclusion: It is concluded that chlorine in EBC and ECP in serum decreased significantly post-season, and this is suggested to mirror the decrement in airborne antigen. It is furthermore proposed that chlorine in EBC and ECP in serum tend to have a similar capacity to identify seasonal variations in airborne pollen in patients with asthma.

  • 64.
    Davidsson, Antette
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Naidu Sjöswärd, Kerstin
    Linköping University, Department of Medicine and Health Sciences, Anesthesiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthesiology and Surgical Centre, Department of Intensive Care UHL.
    Schmekel, Birgitta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Efficacy of Two Breath Condensers: An in Vitro Comparative Study2008Article in journal (Refereed)
    Abstract [en]

    Examination of exhaled breath condensate (EBC) has been suggested to give information about inflammatory airway diseases.

    The aim of the present study was to compare efficacy and variability in gain of two commercially available condensers, ECoScreen® [E] and RTube [R] in an in vitro experimental set up.

    Methods: Test-fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin (BSA) were nebulized. The aerosol was intermittently driven forward by a servoventilator fed by room tempered air, to reach the condenser. Two different concentrations of saline were also dispensed via the same equipment. Analyses of MPO, HNL and chlorine were done by means of ELISA, RIA or a modified adsorbed organic halogen technique (AOX), respectively.

    Results: Significantly higher volumes were recovered by ECoScreen than by RTube during 20-minutes experiments (p<0.001) but not in ten-minute experiments (p>0.05). Based on changes of source concentrations in the nebulizer cup, resulting from nebulization per se, recoveries of HNL tended to be higher by E than by R (p<0.05). In contrast there were no significant differences between condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds and of similar degree for both condensers, despite acceptable inter-assay coefficients of variations of all analyses.

    Conclusion: Condensing efficacy tended to be larger using E than R but there was a large variability in results from both condensers. Individual biomolecules may have their specific characteristics, and this must be taken into consideration when planning studies on EBC. We suggest that further methodological studies of the EBC method are warranted.

  • 65.
    Dyverfeldt, Petter
    et al.
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Eriksson, Jonatan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Sigfridsson, Andreas
    Linköping University, Department of Biomedical Engineering, Medical Informatics. Linköping University, The Institute of Technology. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Escobar Kvitting, John-Peder
    Linköping University, Department of Medical and Health Sciences, Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Carlhäll, Carljohan
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F.
    University of California San Francisco, San Francisco, California, USA.
    Ebbers, Tino
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Extending 4D Flow Visualization to the Human Right Ventricle2009In: Proceedings of International Society for Magnetic Resonance in Medicine: 17th Scientific Meeting 2009, International Society for Magnetic Resonance in Medicine , 2009, p. 3860-3860Conference paper (Refereed)
    Abstract [en]

    The right ventricle has an important role in cardiovascular disease. However, because of the complex geometry and the sensitivity to the respiratory cycle, imaging of the right ventricle is challenging. We investigated whether 3D cine phase-contrast MRI can provide data with sufficient accuracy for visualizations of the 4D blood flow in the right ventricle. Whole-heart 4D flow measurements with optimized imaging parameters and post-processing tools were made in healthy volunteers. Pathlines emitted from the right atrium could be traced through the right ventricle to the pulmonary artery without leaving the blood pool and thereby met our criteria for sufficient accuracy.

  • 66.
    Dyverfeldt, Petter
    et al.
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John Peder
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Boano, G.
    Östergötlands Läns Landsting.
    Carlhäll, Carljohan
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Hermansson, Ulf
    Linköping University, Department of Medicine and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Bolger, A.F.
    University of California, San Fransisco, San Franisco, California, United States.
    Engvall, Jan
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Turbulence Mapping Extends the Utility of Phase-Contrast MRI in Mitral Valve Regurgitation2009In: Proc. Intl. Soc. Mag. Reson. Med., 2009, p. 3939-Conference paper (Refereed)
  • 67.
    Dyverfeldt, Petter
    et al.
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Faculty of Health Sciences. Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology. Linköping University, Department of Medical and Health Sciences, Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medical and Health Sciences, Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Carlhäll, Carl Johan
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Boano, Gabriella
    Östergötlands Läns Landsting, Heart Centre, Department of Cardiology.
    Sigfridsson, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Hermansson, Ulf
    Linköping University, Department of Medical and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Bolger, Ann F.
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Faculty of Health Sciences. Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology. Linköping University, Department of Medical and Health Sciences, Physiology.
    Hemodynamic aspects of mitral regurgitation assessed by generalized phase-contrast MRI2011In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 33, no 3, p. 582-588Article in journal (Refereed)
    Abstract [en]

    Purpose: Mitral regurgitation creates a high velocity jet into the left atrium (LA), contributing both volume andpressure; we hypothesized that the severity of regurgitation would be reflected in the degree of LA flowdistortion.

    Material and Methods: Three-dimensional cine PC-MRI was applied to determine LA flow patterns andturbulent kinetic energy (TKE) in seven subjects (five patients with posterior mitral leaflet prolapse, two normalsubjects). In addition, the regurgitant volume and the time-velocity profiles in the pulmonary veins weremeasured.

    Results: The LA flow in the mitral regurgitation patients was highly disturbed with elevated values of TKE.Peak TKE occurred consistently at late systole. The total LA TKE was closely related to the regurgitant volume.LA flow patterns were characterized by a pronounced vortex in proximity to the regurgitant jet. In some patients,pronounced discordances were observed between individual pulmonary venous inflows, but these could not berelated to the direction of the flow jet or parameters describing global LA hemodynamics.

    Conclusion: PC-MRI permits investigations of atrial and pulmonary vein flow patterns and TKE in significantmitral regurgitation, reflecting the impact of the highly disturbed blood flow that accompanies this importantvalve disease.

  • 68.
    Dyverfeldt, Petter
    et al.
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Escobar Kvitting, John-Peder
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Sigfridsson, Andreas
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Assessment of fluctuating velocities in disturbed cardiovascular blood flow: in vivo feasibility of generalized phase-contrast MRI2008In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 28, no 3, p. 655-663Article in journal (Refereed)
    Abstract [en]

    Purpose

    To evaluate the feasibility of generalized phase-contrast magnetic resonance imaging (PC-MRI) for the noninvasive assessment of fluctuating velocities in cardiovascular blood flow.

    Materials and Methods

    Multidimensional PC-MRI was used in a generalized manner to map mean flow velocities and intravoxel velocity standard deviation (IVSD) values in one healthy aorta and in three patients with different cardiovascular diseases. The acquired data were used to assess the kinetic energy of both the mean (MKE) and the fluctuating (TKE) velocity field.

    Results

    In all of the subjects, both mean and fluctuating flow data were successfully acquired. The highest TKE values in the patients were found at sites characterized by abnormal flow conditions. No regional increase in TKE was found in the normal aorta.

    Conclusion

    PC-MRI IVSD mapping is able to detect flow abnormalities in a variety of human cardiovascular conditions and shows promise for the quantitative assessment of turbulence. This approach may assist in clarifying the role of disturbed hemodynamics in cardiovascular diseases.

  • 69.
    Dyverfeldt, Petter
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Sigfridsson, Andreas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Assessment of Turbulent Flow using Magnetic Resonance Imaging2007In: IX Svenska Kardiovaskulära Vårmötet,2007, 2007Conference paper (Other academic)
    Abstract [en]

      

  • 70.
    Dyverfeldt, Petter
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Sigfridsson, Andreas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Improved image acquisition and processing allow accurate 4D flow investigations of the right ventricle2008In: Medicinteknikdagarna,2008, 2008Conference paper (Other academic)
    Abstract [en]

      

  • 71.
    Dyverfeldt, Petter
    et al.
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics .
    Escobar Kvitting, John-Peder
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland. Linköping University, Center for Medical Image Science and Visualization, CMIV.
    Sigfridsson, Andreas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    In-vivo quantification of turbulent velocity fluctuations2007In: 15th Int Soc Magn Reson Med,2007, 2007Conference paper (Other academic)
  • 72.
    Dyverfeldt, Petter
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Sigfridsson, Andreas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Non-invsive assessment of turbulent flow using magnetic resonance imaging2007In: Medicinteknikdagarna,2007, 2007Conference paper (Other academic)
  • 73.
    Dyverfeldt, Petter
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Thoracic Surgery. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Sigfridsson, Andreas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Mätning och visualisering av blodflödet i höger kammare med tidsupplöst tredimensionell MR2007In: Riksstämman,2007, 2007Conference paper (Other academic)
    Abstract [sv]

       

  • 74.
    Dyverfeldt, Petter
    et al.
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Sigfridsson, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Franzén, Stefan
    Linköping University, Department of Medicine and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Bolger, Ann F.
    University of California San Fransisco, San Fransisco, California, United States.
    Ebbers, Tino
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    In-Vitro Turbulence Mapping in Prosthetic Heart Valves using Generalized Phase-Contrast MRI2009In: Proc. Intl. Soc. Mag. Reson. Med., 2009, p. 3941-Conference paper (Refereed)
  • 75.
    Dyverfeldt, Petter
    et al.
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Gårdhagen, Roland
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics . Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology.
    Sigfridsson, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics . Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology.
    Ebbers, Tinno
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, The Institute of Technology. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    MRI Turbulence Quantification2009In: Proc. Intl. Soc. Mag. Reson. Med., 2009, p. 1858-Conference paper (Refereed)
  • 76.
    Dyverfeldt, Petter
    et al.
    Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Gårdhagen, Roland
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Sigfridsson, Andreas
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Karlsson, Matts
    Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Ebbers, Tino
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    On MRI turbulence quantification2009In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 27, no 7, p. 913-922Article in journal (Refereed)
    Abstract [en]

    Turbulent flow, characterized by velocity fluctuations, accompanies many forms of cardiovascular disease and may contribute to their progression and hemodynamic consequences. Several studies have investigated the effects of turbulence on the magnetic resonance imaging (MRI) signal. Quantitative MRI turbulence measurements have recently been shown to have great potential for application both in human cardiovascular flow and in engineering flow. In this article, potential pitfalls and sources of error in MRI turbulence measurements are theoretically and numerically investigated. Data acquisition strategies suitable for turbulence quantification are outlined. The results show that the sensitivity of MRI turbulence measurements to intravoxel mean velocity variations is negligible, but that noise may degrade the estimates if the turbulence encoding parameter is set improperly. Different approaches for utilizing a given amount of scan time were shown to influence the dynamic range and the uncertainty in the turbulence estimates due to noise. The findings reported in this work may be valuable for both in vitro and in vivo studies employing MRI methods for turbulence quantification.

  • 77.
    Dyverfeldt, Petter
    et al.
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Ebbers, Tino
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Quantification of Turbulance Intensity by Generalizing Phase-Contrast MRI2006Conference paper (Refereed)
  • 78.
    Dyverfeldt, Petter
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Quantification of Turbulence Intensity by Generalizing Phase-Contrast MRI2006In: Proc. Intl. Soc. Mag. Reson. Med. 14,2006, 2006, p. 870-870Conference paper (Refereed)
    Abstract [en]

      

  • 79.
    Dyverfeldt, Petter
    et al.
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Knutsson, Hans
    Linköping University, Department of Biomedical Engineering, Medical Informatics. Linköping University, The Institute of Technology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology. Linköping University, Department of Medical and Health Sciences, Physiology. Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Management and Engineering, Applied Thermodynamics and Fluid Mechanics.
    A novel MRI framework for the quantification of any moment of arbitrary velocity distributions2011In: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 65, no 3, p. 725-731Article in journal (Refereed)
    Abstract [en]

    MRI can measure several important hemodynamic parameters but might not yet have reached its full potential. The most common MRI method for the assessment of flow is phase-contrast MRI velocity mapping that estimates the mean velocity of a voxel. This estimation is precise only when the intravoxel velocity distribution is symmetric. The mean velocity corresponds to the first raw moment of the intravoxel velocity distribution. Here, a generalized MRI framework for the quantification of any moment of arbitrary velocity distributions is described. This framework is based on the fact that moments in the function domain (velocity space) correspond to differentials in the Fourier transform domain (kv-space). For proof-of-concept, moments of realistic velocity distributions were estimated using finite difference approximations of the derivatives of the MRI signal. In addition, the framework was applied to investigate the symmetry assumption underlying phase-contrast MRI velocity mapping; we found that this assumption can substantially affect phase-contrast MRI velocity estimates and that its significance can be reduced by increasing the velocity encoding range.

  • 80.
    Ebbers, Tino
    et al.
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Dyverfeldt, Petter
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Escobar Kvitting, John-Peder
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences.
    Quantification of Mean and Fluctuating Flow2006Conference paper (Refereed)
  • 81.
    Ebbers, Tino
    et al.
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Farneback, Gunnar
    Linköping University, Department of Electrical Engineering. Linköping University, The Institute of Technology.
    Improving Computation of Cardiovascular Relative Pressure Fields From Velocity MRI2009In: JOURNAL OF MAGNETIC RESONANCE IMAGING, ISSN 1053-1807, Vol. 30, no 1, p. 54-61Article in journal (Refereed)
    Abstract [en]

    Purpose: To evaluate a multigrid-based solver for the pressure Poisson equation (PPE) with Galerkin coarsening, which works directly on the specified domain, for the computation of relative pressure fields from velocity MRI data. Materials and Methods: We compared the proposed structure-defined Poisson solver to other popular Poisson solvers working on unmodified rectangular and modified quasirectangular domains using synthetic and in vitro phantoms in which the mathematical solution of the pressure field is known, as well as on in vivo MRI velocity measurements of aortic blood flow dynamics. Results: All three PPE solvers gave accurate results for convex computational domains. Using a rectangular or quasirectangular domain on a more complicated domain, like a c-shape, revealed a systematic underestimation of the pressure amplitudes, while the proposed PPE solver, working directly on the specified domain, provided accurate estimates of the relative pressure fields. Conclusion: Popular iterative approaches with quasirectangular computational domains can lead to significant systematic underestimation of the pressure amplitude. We suggest using a multigrid-based PPE solver with Galerkin coarsening, which works directly on the structure-defined computational domain. This solver provides accurate estimates of the relative pressure fields for both simple and complex geometries with additional significant improvements with respect to execution speed.

  • 82.
    Ebbers, Tino
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Fyrenius, Anna
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology.
    Wigström, Lars
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Calculation of relative cardiac pressure along streamlines using time-resolved 3D phase contrast MRI1999In: Journal of Cardiovascular Magnetic Resonance,1999, 1999, p. 290-291Conference paper (Other academic)
  • 83.
    Ebbers, Tino
    et al.
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Haraldsson, Henrik
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Dyverfeldt, Petter
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Warntjes, Marcel Jan Bertus
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Wigström, Lars
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences.
    Higher order weighted least-squares phase offset correction for improved accuracy in phase-contrast MRI2008Conference paper (Refereed)
    Abstract [en]

    Phase-contrast magnetic resonance imaging has the ability to accurately measure blood flow and myocardial velocities in the human body. Unwanted spatially varying phase offsets are, however, always present and may deteriorate the measurements significantly. Some of these phase offsets can be estimated based on the pulse sequence (1), but effects caused by eddy currents are more difficult to predict. A linear fit of the phase values is often estimated from either a number of manually defined areas containing stationary tissue or by semi-automatic detection of stationary tissue using the

  • 84.
    Ebbers, Tino
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Wigström, Lars
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Fyrenius, Anna
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Particle trace visualization of cardiac flow patterns using 3D phase contrast MRI: an in vitro comparison with streamlines created using dye.1999In: Proc Intl Soc Magn Reson Med 7,1999, 1999, p. 2025-2025Conference paper (Other academic)
  • 85.
    Eidenvall, Lars
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Ask, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Wranne, Bengt
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Determination of regurgitant flow and volume by integrating actual proximal velocities over hemispheres (IPROV) in two orthogonal planes1996In: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 9, no 4, p. 527-538Article in journal (Refereed)
  • 86.
    Eidenvall, Lars
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Ask, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Wranne, Bengt
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Determination of regurgitant flow in a pulsatile model by integrating velocities from the entire 3D proximal velocity field1992In: American Heart Association,1993, 1992Conference paper (Refereed)
  • 87.
    Eidenvall, Lars
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Barclay, S A
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Wranne, Bengt
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ask, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Regurgitant heart valve flow from 3D proximal velocity field - continued search for the ideal method1995In: Medical & Biological Engineering & Computing, ISSN 0140-0118, Vol. 33, p. 131-139Article in journal (Refereed)
  • 88.
    Eidenvall, Lars
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Janerot-Sjöberg, Birgitta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ask, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Wranne, Bengt
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    2D Doppler Flowvelocity profiles can be time corrected with an external ECG delay device1992In: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 5, p. 405-413Article in journal (Refereed)
  • 89.
    Eklund, Anders
    et al.
    Linköping University, Department of Biomedical Engineering, Medical Informatics. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, The Institute of Technology.
    Warntjes, Marcel
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Andersson, Mats
    Linköping University, Department of Biomedical Engineering, Medical Informatics. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, The Institute of Technology.
    Knutsson, Hans
    Linköping University, Department of Biomedical Engineering, Medical Informatics. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, The Institute of Technology.
    Fast Phase Based Registration for Robust Quantitative MRI2010In: Proceedings of the annual meeting of the International Society for Magnetic Resonance in Medicine (ISMRM 2010), 2010Conference paper (Other academic)
    Abstract [en]

    Quantitative magnetic resonance imaging has the major advantage that it handles absolute measurements of physical parameters. Quantitative MRI can for example be used to estimate the amount of different tissue types in the brain, but other applications are possible. Parameters such as relaxation rates R1 and R2 and proton density (PD) are independent of MR scanner settings and imperfections and hence are directly representative of the underlying tissue characteristics. Brain tissue quantification is an important aid for diagnosis of neurological diseases, such as multiple sclerosis (MS) and dementia. It is applied to estimate the volume of each tissue type, such as white tissue, grey tissue, myelin and cerebrospinal fluid (CSF). Tissue that deviates from normal values can be found automatically using computer aided diagnosis. In order for the quantification to have a clinical value, both the time in the MR scanner and the time for the data analysis have to be minimized. A challenge in MR quantification is to keep the scan time within clinically acceptable limits. The quantification method that we have used is based on the work by Warntjes et al.

  • 90.
    Engström, Elias
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Radiology . Linköping University, Center for Medical Image Science and Visualization, CMIV.
    Persson, Anders
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Radiology . Östergötlands Läns Landsting, Centre for Medical Imaging, Department of Radiology UHL. Linköping University, Center for Medical Image Science and Visualization, CMIV.
    Berge, J
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology. Linköping University, Center for Medical Image Science and Visualization, CMIV.
    Wigström, Lars
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Zachrisson, Helene
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology. Linköping University, Center for Medical Image Science and Visualization, CMIV.
    Dual-energy CT of ex-vivo tissue samples.2008In: Cardiovaskulära vårmötet,2008, 2008Conference paper (Refereed)
  • 91.
    Engvall, Jan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation.
    Ask, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Nylander, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Wranne, Bengt
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Importance of collateral vessels in aortic coarctation: Computer simulation at rest and exercise using transmission line elements1994In: Medical & Biological Engineering & Computing, ISSN 0140-0118, Vol. 32, p. 115-122Article in journal (Refereed)
  • 92.
    Engvall, Jan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Nyström, Fredrik
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Surgery. Östergötlands Läns Landsting, MKC-2, GE: endomed.
    Daytime ambulatory blood pressure correlates strongly with the echocardiographic diameter of aortic coarctation2001In: Scandinavian Cardiovascular Journal, ISSN 1401-7431, E-ISSN 1651-2006, Vol. 35, no 5, p. 335-339Article in journal (Refereed)
    Abstract [en]

    Objective.-To relate the echocardiographic aortic arch-diameter to ambulatory and clinic blood pressure (BP) in patients with aortic coarctation. Design.-Eighteen adult patients (50% men) were recruited from the coarctation registry of the Linkoping Heart Centre. Biplane-trans-oesophageal echocardiography (TEE) was performed with Acuson XP 128/10, ambulatory BP was recorded with Spacelab models 90202/90205. Results.-Systolic clinic and ambulatory BP levels were higher in patients than in the 36 controls (clinic BP: 146 ▒ 25 mmHg vs 119 ▒ 10 mmHg, p = 0.0009, ambulatory BP: 140 ▒ 18 mmHg vs 124 ▒ 11 mmHg, p = 0.009). The differences in diastolic BP levels were less obvious (clinic BP: 87 ▒ 16 mmHg vs 76 ▒ 8 mmHg, p = 0.02, ambulatory BP: 84 ▒ 13 mmHg vs 77 ▒ 9 mmHg, p = 0.052). Daytime ambulatory BP was more strongly related than clinic BP to the coarctation diameter (AD) (systolic BP r = -0.73, p = 0.0006 and r = -0.61, p = 0.007, respectively). In surgically corrected patients (n = 14) only the correlations between ambulatory systolic daytime (r = -0.61, p = 0.02) and night-time (r = -0.58, p = 0.03) BP to AD was statistically significant. Conclusion.-Ambulatory BP correlates strongly with aortic coarctation measured by TEE and would thus be the preferred technique for evaluating BP in this patient category.

  • 93.
    Ennis, DB
    et al.
    Stanford University.
    Nguyen, TC
    Stanford University.
    Itoh, A
    Stanford University.
    Carlhäll, Carljohan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Oakes, RA
    Stanford University.
    Bothe, W
    Stanford University.
    Liang, D
    Stanford University.
    Miller, DC
    Stanford University.
    Ingels, NB
    Stanford University.
    Non-uniform transmural remodeling in ovine chronic mitral regurgitation. Experimental biology.2008In: Annual meeting of the American Physiological Society,2008, 2008Conference paper (Refereed)
    Abstract [en]

      

  • 94.
    Eriksson, Jonatan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    Carlhäll, Carljohan
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Dyverfeldt, Petter
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Semi-automatic quantification of 4D left ventricular blood flow2010In: JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE, ISSN 1097-6647, Vol. 12, no 9Article in journal (Refereed)
    Abstract [en]

    Background: The beating heart is the generator of blood flow through the cardiovascular system. Within the hearts own chambers, normal complex blood flow patterns can be disturbed by diseases. Methods for the quantification of intra-cardiac blood flow, with its 4D (3D+time) nature, are lacking. We sought to develop and validate a novel semi-automatic analysis approach that integrates flow and morphological data. Method: In six healthy subjects and three patients with dilated cardiomyopathy, three-directional, three-dimensional cine phase-contrast cardiovascular magnetic resonance (CMR) velocity data and balanced steady-state free-precession long- and short-axis images were acquired. The LV endocardium was segmented from the short-axis images at the times of isovolumetric contraction (IVC) and isovolumetric relaxation (IVR). At the time of IVC, pathlines were emitted from the IVC LV blood volume and traced forwards and backwards in time until IVR, thus including the entire cardiac cycle. The IVR volume was used to determine if and where the pathlines left the LV. This information was used to automatically separate the pathlines into four different components of flow: Direct Flow, Retained Inflow, Delayed Ejection Flow and Residual Volume. Blood volumes were calculated for every component by multiplying the number of pathlines with the blood volume represented by each pathline. The accuracy and inter- and intra-observer reproducibility of the approach were evaluated by analyzing volumes of LV inflow and outflow, the four flow components, and the end-diastolic volume. Results: The volume and distribution of the LV flow components were determined in all subjects. The calculated LV outflow volumes [ml] (67 +/- 13) appeared to fall in between those obtained by through-plane phase-contrast CMR (77 +/- 16) and Doppler ultrasound (58 +/- 10), respectively. Calculated volumes of LV inflow (68 +/- 11) and outflow (67 +/- 13) were well matched (NS). Low inter- and intra-observer variability for the assessment of the volumes of the flow components was obtained. Conclusions: This semi-automatic analysis approach for the quantification of 4D blood flow resulted in accurate LV inflow and outflow volumes and a high reproducibility for the assessment of LV flow components.

  • 95.
    Eriksson, Jonatan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences.
    Dyverfeldt, Petter
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Carlhäll, Carljohan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Improved visualization and quantification of 4D intracardiac blood flow2008In: Medicinteknikdagarna,2008, 2008Conference paper (Other academic)
  • 96.
    Eriksson, Per
    et al.
    Linköping University, Department of Medicine and Health Sciences, Internal Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medicine, Department of Nephrology UHL.
    Mohammed, Ahmed Abdulilah
    Linköping University, Department of Medicine and Health Sciences, Radiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medical Imaging, Department of Radiology in Linköping.
    De Geer, Jakob
    Linköping University, Department of Medicine and Health Sciences, Radiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medical Imaging, Department of Radiology in Linköping. Linköping University, Center for Medical Image Science and Visualization, CMIV.
    Kihlberg, Johan
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Radiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medical Imaging, Department of Radiology in Linköping.
    Persson, Anders
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Radiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medical Imaging, Department of Radiology in Linköping.
    Granerus, Göran
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Nyström, Fredrik
    Linköping University, Department of Medicine and Health Sciences, Internal Medicine . Linköping University, Faculty of Health Sciences.
    Smedby, Örjan
    Linköping University, Center for Medical Image Science and Visualization, CMIV. Linköping University, Department of Medicine and Health Sciences, Radiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medical Imaging, Department of Radiology in Linköping.
    Non-invasive investigations of potential renal artery stenosis in renal insufficiency2010In: Nephrology, Dialysis and Transplantation, ISSN 0931-0509, E-ISSN 1460-2385, Vol. 25, no 11, p. 3607-3614Article in journal (Refereed)
    Abstract [en]

    Background. The diagnostic value of non-invasive methods for diagnosing renal artery stenosis in patients with renal insufficiency is incompletely known.

    Methods. Forty-seven consecutive patients with moderately impaired renal function and a clinical suspicion of renal artery stenosis were investigated with computed tomography angiography (CTA), gadolinium-enhanced magnetic resonance angiography (MRA), contrast-enhanced Doppler ultrasound and captopril renography. The primary reference standard was stenosis reducing the vessel diameter by at least 50% on CTA, and an alternative reference standard (‘morphological and functional stenosis’) was defined as at least 50% diameter reduction on CTA or MRA, combined with a positive finding from ultrasound or captopril renography.

    Results. The frequency of positive findings, calculated on the basis of individual patients, was 70% for CTA, 60% for MRA, 53% for ultrasound and 30% for captopril renography. Counting kidneys rather than patients, corresponding frequencies were 53%, 41%, 29% and 15%, respectively. In relation to the CTA standard, the sensitivity (and specificity) at the patient level was 0.81 (0.79) for MRA, 0.70 (0.89) for ultrasound and 0.42 (1.00) for captopril renography, and at the kidney level 0.76 (0.82), 0.53 (0.81) and 0.30 (0.86), respectively. Relative to the alternative reference standard, corresponding values at the patient level were 1.00 (0.62) for CTA, 0.90 (0.69) for MRA, 0.91 (1.00) for ultrasound and 0.67 (1.00) for captopril renography, and at the kidney level 0.96 (0.76), 0.85 (0.79), 0.71 (0.97) and 0.50 (0.97), respectively.

    Conclusions. CTA and MRA are superior to ultrasound and captopril renography at diagnosing morphological stenosis, but ultrasound may be useful as a screening method and captopril renography for verifying renin-dependent hypertension.

  • 97.
    Escobar Kvitting, John-Peder
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Brandt, Einar
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Wigström, Lars
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Visualization of flow in the aorta using time-resolved 3D phase contrast MRI2001In: Proc. Intl. Soc. Mag. Reson. Med.,2001, 2001, p. 378-378Conference paper (Refereed)
  • 98.
    Escobar Kvitting, John-Peder
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Dyverfeldt, Petter
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Boano, G
    Sigfridsson, Andreas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Multidimensional Turbulence Mapping in Mitral Insufficiency2008In: Soc Cardiovascular Magn Reson. 11th Scientific Sessions,2008, 2008Conference paper (Other academic)
  • 99.
    Escobar Kvitting, John-Peder
    et al.
    Linköping University, Department of Medicine and Health Sciences, Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Dyverfeldt, Petter
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Carlhäll, Carljohan
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    F Bolger, Ann
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Engvall, Jan
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    MR allows a unique possibility to see how the blood flow affects the cardiovascular system [MR ger unik möjlighet se hur blodflödet inverkar på hjärtkärlsystemet.]2009In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 106, no 30-31, p. 1901-1904Article, review/survey (Refereed)
    Abstract [en]

    [No abstract available]

  • 100.
    Escobar Kvitting, John-Peder
    et al.
    Linköping University, Department of Medicine and Health Sciences, Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Dyverfeldt, Petter
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Sigfridsson, Andreas
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Franzen, Stefan
    Linköping University, Department of Medicine and Health Sciences, Thoracic Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Wigström, Lars
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    In Vitro Assessment of Flow Patterns and Turbulence Intensity in Prosthetic Heart Valves Using Generalized Phase-Contrast MRI2010In: JOURNAL OF MAGNETIC RESONANCE IMAGING, ISSN 1053-1807, Vol. 31, no 5, p. 1075-1080Article in journal (Refereed)
    Abstract [en]

    Purpose: To assess in vitro the three-dimensional mean velocity field and the extent and degree of turbulence intensity (TI) in different prosthetic heart valves using a generalization of phase-contrast MRI (PC-MRI). Materials and Methods: Four 27-mm aortic valves (Bjork-Shiley Monostrut tilting-disc, St. Jude Medical Standard bileaflet, Medtronic Mosaic stented and Freestyle stentless porcine valve) were tested under steady inflow conditions in a Plexiglas phantom. Three-dimensional PC-MRI data were acquired to measure the mean velocity field and the turbulent kinetic energy (TKE), a direction-independent measure of TI. Results: Velocity and TI estimates could be obtained up and downstream of the valves, except where metallic structure in the valves caused signal void. Distinct differences in the location, extent, and peak values of velocity and TI were observed between the valves tested. The maximum values of TKE varied between the different valves: tilting disc, 100 J/m(3); bileaflet, 115 J/m(3); stented, 200 J/m(3); stentless, 145 J/m(3). Conclusion: The TI downstream from a prosthetic heart valve is dependent on the specific valve design. Generalized PC-MRI can be used to quantify velocity and TI downstream from prosthetic heart valves, which may allow assessment of these aspects of prosthetic valvular function in postoperative patients.

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