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  • 201.
    Schon, Thomas
    et al.
    Kalmar County Hospital.
    Labbe Sandelin, Lisa
    Kalmar County Hospital.
    Bonnedahl, Jonas
    Kalmar County Hospital.
    Hedeback, Fredrika
    Kalmar County Hospital.
    Wistedt, Annika
    Kalmar County Hospital.
    Brudin, Lars
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Jarnheimer, Per-Ake
    Kalmar County Hospital.
    A comparative study of three methods to evaluate an intervention to improve empirical antibiotic therapy for acute bacterial infections in hospitalized patients2011Inngår i: SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES, ISSN 0036-5548, Vol. 43, nr 4, s. 251-257Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: In order to limit the use of broad-spectrum antibiotics, standardized empirical therapy against acute bacterial infections has been advocated. Methods: Guidelines for acute bacterial infections recommending increased usage of benzylpenicillin and restricted use of fluoroquinolones and cephalosporins have been implemented in Kalmar County, Sweden. We evaluated this strategy by recording therapy in patients with bacteraemia, antibiotic requisition, and point prevalence surveys prior to this intervention and at 6 and 12 months after. Results: Comparing the methods simultaneously, there was good agreement between them and an overall significant change in antibiotic usage. There was a significant shift from cefuroxime to cefotaxime and a borderline significant increase in the use of benzylpenicillin (p == 0.057). Based on the defined daily dose (DDD), a highly significant decrease in total cefotaxime and cefuroxime usage was observed that was not detected when applying the prescribed daily dose (PDD), which is adapted to local treatment practices. No change was found in mortality in Staphylococcus aureus bacteraemia or the incidence of Clostridium difficile infection. Conclusions: We conclude that the implementation of the new guidelines has resulted in a significant change in antibiotic usage, which could be conveniently monitored by antibiotic requisition if PDD is used in addition to DDD.

  • 202.
    Selga, Gunthars
    et al.
    Sports Medicine State Agency, Riga, Latvia .
    Kalina, Liga
    Sports Medicine State Agency, Riga, Latvia .
    Dahlström, Örjan
    Linköpings universitet, Institutionen för beteendevetenskap och lärande, Handikappvetenskap. Linköpings universitet, Filosofiska fakulteten.
    Timpka, Toomas
    Linköpings universitet, Institutionen för medicin och hälsa, Socialmedicin och folkhälsovetenskap. Linköpings universitet, Hälsouniversitetet.
    Sauka, Melita
    Sports Medicine State Agency, Riga, Latvia .
    Priedite, Ilga Sarmite
    Sports Medicine State Agency, Riga, Latvia .
    Ligere, Renate
    University of Latvia, Riga, Latvia .
    Nylander, Eva
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    The body mass index underestimates thinness in adolescent athletes2011Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Objective: Children and adolescents are often involved in sports in which weight loss is perceived as an advantage. Adolescents try to lose weight or body fat in the interest of improved appearance or athletic performance. Unhealthy weight-control practices can impair athletic performance and increase injury risk. They also may result in medical complications including delayed physical maturation, oligomenorrhea and amenorrhea in such as the female athletes, development of eating disorders, potential permanent growth impairment, etc. Body mass index (BMI, kg/m²) is the most widely used screening tool for underweight, especially in general practice. In athletes BMI as indicator of thinness can be questioned. The aim of the study was to determine sensitivity and specificity of thinness among healthy young athletes based on body mass index (BMI, kg/m²) (using the IOTF criteria [1]), and the % body fat (%BF) determined by the bioimpedance method and using percentile lines from UK study [2].

    Subjects and methods: We used data from the Sports Medicine State Agency database on health check-ups conducted between 2008 and 2009. Cross-sectional study using cluster sampling (sports organisations) was implemented, analysing data from 7 667 young athletes (5222 male and 2 445 female) at age from 7 to 17 years old. Athletes were categorised as belonging to lean (n=2 390) or non-lean (n=5 277) sports [3]. Body composition (%BF) was measured by a multi frequency 8-polar bioelectrical impedance leg-to-hand analyser (X-Scan pluss II, Korea).

    Results: The prevalence of underweight according to IOTF BMI cut-off values was 3,2% (n=216, CI 95% 0,88-5,6), the corresponding values of underfat using body fat cut-offs was 59,42% (n=4556, CI 95% 58,32-60,52). The performance of BMI cut-off values for identification of thinness individuals with %BF as reference is displayed in Table 1 [Tab. 1].

    Conclusion: The sensitivities of the BMI-derived cut-offs were mostly below 20%, while the specificities were high. Our results suggest that the low sensitivity IOTF BMI cut-offs leads to a considerable underestimation of the true prevalence of thinness in youth athletes.

  • 203.
    Semark, B
    et al.
    University of Kalmar.
    Fredlund, K
    Primary Health Centre, Kalmar.
    Astrand, B
    University of Kalmar.
    Brudin, Lars
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Reimbursement for drugs - a register study comparing economic outcome for five healthcare centres in areas with different socioeconomic conditions2009Inngår i: SCANDINAVIAN JOURNAL OF PUBLIC HEALTH, ISSN 1403-4948, Vol. 37, nr 6, s. 647-653Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aims: Previous studies have indicated the negative effects of socioeconomic deprivation on health status and morbidity. Nevertheless, the economic assignment systems for pharmaceutical benefits in Sweden do not take socioeconomic status (SES) into account. The aim of the study was, therefore, to compare reimbursement for subsidized drugs at primary healthcare centres (HCCs) with differing socioeconomic conditions in relation to real costs. The word reimbursement is used to denote economic compensation to the HCCs from the county council for drug benefit costs. Methods: The numbers of individuals dispensed drugs, total costs and reimbursement at five HCCs with different socioeconomic conditions were compared. A socioeconomic index was calculated for each HCC on the basis of information from the municipality registries on income ( with negative sign), assistance allowance, education, foreign background, and unemployment. Register data on drug benefit costs were retrieved from the National Corporation of Pharmacies (Apoteket AB) and the Swedish Prescribed Drug Register at the National Board of Health and Welfare. Data on listed and unlisted citizens at the Kalmar County Council and on public statistics from registers at the HCC municipalities where the HCCs were situated were retrieved. Results: There was an almost inverse linear relationship between total cost compensation and the socioeconomic index (n = 5; r = -0.99; p = 0.001). The HCCs with the lowest SES received lower cost compensation. Conclusions: HCCs responsible for citizens with lower SES appeared to be disadvantaged by the prevalent reimbursement system in Sweden, thereby increasing differences in the state of health of the citizens. This, in turn, hampers health preventing programmes and lifestyle interventions. An HCC-specific standardized summary of socioeconomic burden is presented.

  • 204.
    Sengupta, Partho P
    et al.
    Mt Sinai School of Medicine.
    Pedrizzetti, Gianni
    University of Trieste.
    Kilner, Philip J
    Royal Brompton Hospital.
    Kheradvar, Arash
    University of Calif Irvine.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik.
    Tonti, Giovanni
    SS Annunziata Hospital.
    Fraser, Alan G
    Cardiff University.
    Narula, Jagat
    Mt Sinai School of Medicine.
    Emerging Trends in CV Flow Visualization2012Inngår i: JACC Cardiovascular Imaging, ISSN 1936-878X, E-ISSN 1876-7591, Vol. 5, nr 3, s. 305-316Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Blood flow patterns are closely linked to the morphology and function of the cardiovascular system. These patterns reflect the exceptional adaptability of the cardiovascular system to maintain normal blood circulation under a wide range of workloads. Accurate retrieval and display of flow-related information remains a challenge because of the processes involved in mapping the flow velocity fields within specific chambers of the heart. We review the potentials and pitfalls of current approaches for blood flow visualization, with an emphasis on acquisition, display, and analysis of multidirectional flow. This document is divided into 3 sections. First, we provide a descriptive outline of the relevant concepts in cardiac fluid mechanics, including the emergence of rotation in flow and the variables that delineate vortical structures. Second, we elaborate on the main methods developed to image and visualize multidirectional cardiovascular flow, which are mainly based on cardiac magnetic resonance, ultrasound Doppler, and contrast particle imaging velocimetry, with recommendations for developing dedicated imaging protocols. Finally, we discuss the potential clinical applications and technical challenges with suggestions for further investigations.

  • 205.
    Settergren, Magnus
    et al.
    Karolinska universitetssjukhuset, Stockholm.
    Nielsen, Nils-Erik
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Jönsson, Anders
    Karolinska universitetssjukhuset, Stockholm.
    Erlinge, David
    Skånes universitetssjukhus, Lund.
    Nylander, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Harnek, Jan
    Skånes universitetssjukhus, Lund.
    Mitralisklaff­sjukdom: »Nu kan vi både öppna och stänga«: [Mitral valve disease:"Now we can both open and close"]2011Inngår i: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 108, nr 20, s. 1117-1122Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [sv]

    Mitralisinsufficiens är vanligt förekommande bland äldre. En betydande andel av patienterna lämpar sig inte för öppen kirurgi på grund av ökad operationsrisk. Det finns därför ett behov av ett mind­re invasivt behandlingsalternativ för denna patientgrupp.

    För att behandla mitralisinsufficiens har ett flertal perkutana tekniker utvecklats med lovande initiala resultat och stor framtida klinisk potential.

    Mitralisstenos orsakas oftast av genomgången reumatisk feber. Symtomgivande mitralisstenos kan behandlas med kir­urgi eller ballongdilatation.

    Mitralisstenosens patofysiologi och diagnostik presenteras, liksom olika metoder för bedömning av svårighetsgrad och val av behandling. Slutligen beskrivs det praktiska förfarandet vid mitralisvalvulotomi.

  • 206.
    Sigfridsson, Andreas
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Tekniska högskolan.
    Multidimensional MRI  of Myocardial Dynamics: Acquisition, Reconstruction and Visualization2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Methods for measuring deformation and motion of the human heart in-vivo are crucial in the assessment of cardiac function. Applications ranging from basic physiological research, through early detection of disease to follow-up studies, all rely on the quality of the measurements of heart dynamics. This thesis presents new improved magnetic resonance imaging methods for acquisition, image reconstruction and visualization of cardiac motion and deformation.As the heart moves and changes shape during the acquisition, synchronization to the heart dynamics is necessary. Here, a method to resolve not only the cardiac cycle but also the respiratory cycle is presented. Combined with volumetric imaging, this produces a five-dimensional data set with two cyclic temporal dimensions. This type of data reveals unique physiological information, such as interventricular coupling in the heart in different phases of the respiratory cycle.The acquisition can also be sensitized to motion, measuring not only the magnitude of the magnetization but also a signal proportional to local velocity or displacement. This allows for quantification of the motion which is especially suitable for functional study of the cardiac deformation. In this work, an evaluation of the influence of several factors on the signal-to-noise ratio is presented for in-vivo displacement encoded imaging. Additionally, an extension of the method to acquire multiple displacement encoded slices in a single breath hold is also presented.Magnetic resonance imaging is usually associated with long scan times, and many methods exist to shorten the acquisition time while maintaining acceptable image quality. One class of such methods involves acquiring only a sparse subset of k-space. A special reconstruction is then necessary in order to obtain an artifact-free image. One family of these reconstruction techniques tailored for dynamic imaging is the k-t BLAST approach, which incorporates data-driven prior knowledge to suppress aliasing artifacts that otherwise occur with the sparse sampling. In this work, an extension of the original k-t BLAST method to two temporal dimensions is presented and applied to data acquired with full coverage of the cardio-respiratory cycles. Using this technique, termed k-t2 BLAST, simultaneous reduction of scan time and improved spatial resolution is demonstrated. Further, the loss of temporal fidelity when using the k-t BLAST approach is investigated, and an improved reconstruction is proposed for the application of cardiac function analysis.Visualization is a crucial part of the imaging chain. Scalar data, such as regular anatomical images, are straightforward to display. Myocardial strain and strain-rate, however, are tensor quantities which do not lend themselves to direct visualization. The problem of visualizing the tensor field is approached in this work by combining a local visualization that displays all degrees of freedom for a single tensor with an overview visualization using a scalar field representation of the complete tensor field. The scalar field is obtained by iterated adaptive filtering of a noise field, creating a continuous geometrical representation of the myocardial strain-rate tensor field.The results of the work presented in this thesis provide opportunities for improved imaging of myocardial function, in all areas of the imaging chain; acquisition, reconstruction and visualization.

     

    Delarbeid
    1. Tensor Field Visualisation using Adaptive Filtering of Noise Fields combined with Glyph Rendering
    Åpne denne publikasjonen i ny fane eller vindu >>Tensor Field Visualisation using Adaptive Filtering of Noise Fields combined with Glyph Rendering
    2002 (engelsk)Inngår i: IEEE Visualization 2002 Conference, IEEE , 2002, s. 371-378Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    While many methods exist for visualising scalar and vector data, visualisation of tensor data is still troublesome. We present a method for visualising second order tensors in three dimensions using a hybrid between direct volume rendering and glyph rendering.

    An overview scalar field is created by using three-dimensional adaptive filtering of a scalar field containing noise. The filtering process is controlled by the tensor field to be visualised, creating patterns that characterise the tensor field. By combining direct volume rendering of the scalar field with standard glyph rendering methods for detailed tensor visualisation, a hybrid solution is created.

    A combined volume and glyph renderer was implemented and tested with both synthetic tensors and strain-rate tensors from the human heart muscle, calculated from phase contrast magnetic resonance image data. A comprehensible result could be obtained, giving both an overview of the tensor field as well as detailed information on individual tensors.

    sted, utgiver, år, opplag, sider
    IEEE, 2002
    Emneord
    Tensor, Visualisation, Volume rendering, Glyph rendering, Hybrid rendering, Strain-rate
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-14011 (URN)
    Tilgjengelig fra: 2006-10-04 Laget: 2006-10-04 Sist oppdatert: 2013-09-03bibliografisk kontrollert
    2. Five-dimensional MRI Incorporating Simultaneous Resolution of Cardiac and Respiratory Phases for Volumetric Imaging
    Åpne denne publikasjonen i ny fane eller vindu >>Five-dimensional MRI Incorporating Simultaneous Resolution of Cardiac and Respiratory Phases for Volumetric Imaging
    2006 (engelsk)Inngår i: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 25, nr 1, s. 113-121Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Purpose

    To develop a new volumetric imaging method resolved over both the cardiac and respiratory cycles, to enable future physiological and pathophysiological studies of respiratory-related cardiac motion.

    Materials and Methods

    An acquisition scheme is proposed whereby the k-space acquisition order is controlled in real-time by the current cardiac and respiratory phases. To reduce eddy-current effects induced by sudden jumps in k-space, the acquisition order is further optimized by the use of a Hilbert curve trajectory in the ky-kz plane. A complete three-dimensional (3D) k-space is acquired for all combinations of cardiac and respiratory phases, yielding a five-dimensional (5D) data set after retrospective reconstruction.

    Results

    Left (LV) and right ventricular (RV) wall excursion was measured in a healthy volunteer. Diastolic LV diameter was shown to increase during expiration and decrease during inspiration, as expected from previous echocardiography studies. The LV volume was estimated for all cardiac and respiratory phases with the use of a fully 3D segmentation tool. The results confirmed that the diastolic LV volume increased during expiration and decreased during inspiration.

    Conclusion

    With its ability to measure motion anywhere in the heart, the described technique provides a promising approach for in-depth description of interventricular coupling, including 3D ventricular volumes, during both the cardiac and respiratory cycles.

    Emneord
    respiration, septal motion, interventricular coupling, volumetric MRI, cine imaging
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-14012 (URN)10.1002/jmri.20820 (DOI)000243250800014 ()
    Tilgjengelig fra: 2006-10-04 Laget: 2006-10-04 Sist oppdatert: 2017-12-13bibliografisk kontrollert
    3. k-t2 BLAST: Exploiting spatiotemporal structure in simultaneously cardiac and respiratory time-resolved volumetric imaging
    Åpne denne publikasjonen i ny fane eller vindu >>k-t2 BLAST: Exploiting spatiotemporal structure in simultaneously cardiac and respiratory time-resolved volumetric imaging
    2007 (engelsk)Inngår i: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 58, nr 5, s. 922-930Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Multidimensional imaging resolving both the cardiac and respiratory cycles simultaneously has the potential to describe important physiological interdependences between the heart and pulmonary processes. A fully five-dimensional acquisition with three spatial and two temporal dimensions is hampered, however, by the long acquisition time and low spatial resolution. A technique is proposed to reduce the scan time substantially by extending the k-t BLAST framework to two temporal dimensions. By sampling the k-t space sparsely in a lattice grid, the signal in the transform domain, x-f space, can be densely packed, exploiting the fact that large regions in the field of view have low temporal bandwidth. A volumetric online prospective triggering approach with full cardiac and respiratory cycle coverage was implemented. Retrospective temporal interpolation was used to refine the timing estimates for the center of k-space, which is sampled for all cardiac and respiratory time frames. This resulted in reduced reconstruction error compared with conventional k-t BLAST reconstruction. The k-t2 BLAST technique was evaluated by decimating a fully sampled five-dimensional data set, and feasibility was further demonstrated by performing sparsely sampled acquisitions. Compared to the fully sampled data, a fourfold improvement in spatial resolution was accomplished in approximately half the scan time.

    Emneord
    Cine imaging, k-t BLAST, Respiration, Volumetric MRI
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-47833 (URN)10.1002/mrm.21295 (DOI)000250560000009 ()
    Tilgjengelig fra: 2009-10-11 Laget: 2009-10-11 Sist oppdatert: 2017-12-13bibliografisk kontrollert
    4. Improving Temporal Fidelity in k-t BLAST MRI Reconstruction
    Åpne denne publikasjonen i ny fane eller vindu >>Improving Temporal Fidelity in k-t BLAST MRI Reconstruction
    Vise andre…
    2007 (engelsk)Inngår i: Medical Image Computing and Computer-Assisted Intervention – MICCAI 2007: 10th International Conference, Brisbane, Australia, October 29 - November 2, 2007, Proceedings, Part II / [ed] Ayache, N; Ourdelin, S; Maeder, A, Springer Berlin/Heidelberg, 2007, s. 385-392Konferansepaper, Publicerat paper (Fagfellevurdert)
    Abstract [en]

    Studies of myocardial motion using magnetic resonance imaging usually require multiple breath holds and several methods have been proposed in order to reduce the scan time. Rapid imaging using k-t BLAST has gained much attention with its high reduction factors and image quality. Temporal smoothing, however, may reduce the accuracy when assessing cardiac function. In the present work, a modified reconstruction filter is proposed, that preserves more of the high temporal frequencies. Artificial decimation of a fully sampled data set was used to evaluate the reconstruction filter. Compared to the conventional k-t BLAST reconstruction, the modified filter produced images with sharper temporal delineation of the myocardial walls.  Quantitative analysis by means of regional velocity estimation showed that the modified reconstruction filter produced more accurate velocity estimations.

    sted, utgiver, år, opplag, sider
    Springer Berlin/Heidelberg, 2007
    Serie
    Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349 ; 4792
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-21764 (URN)10.1007/978-3-540-75759-7_47 (DOI)000250917700047 ()978-3-540-75758-0 (ISBN)978-3-540-75759-7 (ISBN)
    Konferanse
    MICCAI 2007, 10th International Conference, Brisbane, Australia, October 29 - November 2, 2007
    Tilgjengelig fra: 2009-10-05 Laget: 2009-10-05 Sist oppdatert: 2018-02-09bibliografisk kontrollert
    5. Single Breath Hold Multiple Slice DENSE MRI
    Åpne denne publikasjonen i ny fane eller vindu >>Single Breath Hold Multiple Slice DENSE MRI
    Vise andre…
    2010 (engelsk)Inngår i: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 63, nr 5, s. 1411-1414Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    A method to acquire multiple displacement encoded slices within asingle breath hold is presented. Efficiency is improved overconventional Displacement ENcoding with Stimulated Echoes (DENSE) without compromising image quality by read-out of multiple slices inthe same cardiac cycle, thus utilizing the position encoded stimulatedecho available in the whole heart. The method was evaluated bycomparing strain values obtained using the proposed method to strainvalues obtained by conventional separate breath hold single-sliceDENSE acquisitions. Good agreement (Lagrangian E2 strainbias=0.000, 95% limits of agreement ±0.04,root-mean-square-difference 0.02 (9.4% of the mean end-systolic E2)) was found between the methods, indicating that the proposedmethod can replace a multiple breath hold acquisition. Eliminating theneed for multiple breath holds reduces the risk of changes in breathhold positions or heart rate, results in higher patient comfort andfacilitates inclusion of DENSE in a clinical routine protocol.

    sted, utgiver, år, opplag, sider
    John Wiley and Sons, Ltd, 2010
    Emneord
    DENSE, strain, multi-slice, breath hold, cardiac function
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-51974 (URN)10.1002/mrm.22305 (DOI)000277098100030 ()
    Tilgjengelig fra: 2009-11-25 Laget: 2009-11-25 Sist oppdatert: 2017-12-12bibliografisk kontrollert
    6. In-vivo SNR in DENSE MRI: temporal and regional effects of field strength, receiver coil sensitivity, and flip angle strategies
    Åpne denne publikasjonen i ny fane eller vindu >>In-vivo SNR in DENSE MRI: temporal and regional effects of field strength, receiver coil sensitivity, and flip angle strategies
    Vise andre…
    2011 (engelsk)Inngår i: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 29, nr 2, s. 202-208Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Aim: The influences on the SNR of DENSE MRI of field strength, receiver coil sensitivity and choice of flip angle strategy have been previously investigated individually. In this study, all of these parameters have been investigated in the same setting, and a mutual comparison of their impact on SNR is presented.

    Materials and methods: Ten healthy volunteers were imaged in a 1.5T and a 3T MRI system, using standard 5 or 6 channel cardiac coils as well as 32 channel coils, with four different excitation patterns. Variation of spatial coil sensitivity was assessed by regional SNR analysis.

    Results: SNR ranging from 2.8 to 30.5 was found depending on the combination of excitation patterns, coil sensitivity and field strength. The SNR at 3T was 53 ± 26% higher than at 1.5T (p<0.001), whereas spatial differences of 59 ± 26% were found in the ventricle (p<0.001). 32 channel coils provided 52 ± 29% higher SNR compared to standard 5 or 6 channel coils (p<0.001). A fixed flip angle strategy provided an excess of 50% higher SNR in half of the imaged cardiac cycle compared to a sweeping flip angle strategy, and a single phase acquisition provided a six-fold increase of SNR compared to a cine acquisition.

    Conclusion: The effect of field strength and receiver coil sensitivity influences the SNR with the same order of magnitude, whereas flip angle strategy can have a larger effect on SNR. Thus, careful choice of imaging hardware in combination with adaptation of the acquisition protocol is crucial in order to realize sufficient SNR in DENSE MRI.

    sted, utgiver, år, opplag, sider
    Elsevier, 2011
    Emneord
    DENSE, strain, SNR, flip angle, coil sensitivity
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-51975 (URN)10.1016/j.mri.2010.08.016 (DOI)000287390500008 ()
    Merknad

    Original Publication: Andreas Sigfridsson, Henrik Haraldsson, Tino Ebbers, Hans Knutsson and Hajime Sakuma, In-vivo SNR in DENSE MRI: temporal and regional effects of field strength, receiver coil sensitivity, and flip angle strategies, 2011, Magnetic Resonance Imaging, (29), 2, 202-208. http://dx.doi.org/10.1016/j.mri.2010.08.016 Copyright: Elsevier Science B.V., Amsterdam. http://www.elsevier.com/

    Tilgjengelig fra: 2009-11-25 Laget: 2009-11-25 Sist oppdatert: 2017-12-12
  • 207.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Institutionen för medicinsk teknik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Andersson, Mats
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Wigström, Lars
    Linköpings universitet, Institutionen för medicinsk teknik, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Kvitting, John-Peder Escobar
    Linköpings universitet, Institutionen för medicinsk teknik, Centrum för medicinsk bildvetenskap och visualisering. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Thorax-kärlkliniken.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Improving Temporal Fidelity in k-t BLAST MRI Reconstruction2007Inngår i: Medical Image Computing and Computer-Assisted Intervention – MICCAI 2007: 10th International Conference, Brisbane, Australia, October 29 - November 2, 2007, Proceedings, Part II / [ed] Ayache, N; Ourdelin, S; Maeder, A, Springer Berlin/Heidelberg, 2007, s. 385-392Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Studies of myocardial motion using magnetic resonance imaging usually require multiple breath holds and several methods have been proposed in order to reduce the scan time. Rapid imaging using k-t BLAST has gained much attention with its high reduction factors and image quality. Temporal smoothing, however, may reduce the accuracy when assessing cardiac function. In the present work, a modified reconstruction filter is proposed, that preserves more of the high temporal frequencies. Artificial decimation of a fully sampled data set was used to evaluate the reconstruction filter. Compared to the conventional k-t BLAST reconstruction, the modified filter produced images with sharper temporal delineation of the myocardial walls.  Quantitative analysis by means of regional velocity estimation showed that the modified reconstruction filter produced more accurate velocity estimations.

  • 208.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Heiberg, Einar
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Wigström, Lars
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Tensor Field Visualisation using Adaptive Filtering of Noise Fields combined with Glyph Rendering2002Inngår i: IEEE Visualization 2002 Conference, IEEE , 2002, s. 371-378Konferansepaper (Fagfellevurdert)
    Abstract [en]

    While many methods exist for visualising scalar and vector data, visualisation of tensor data is still troublesome. We present a method for visualising second order tensors in three dimensions using a hybrid between direct volume rendering and glyph rendering.

    An overview scalar field is created by using three-dimensional adaptive filtering of a scalar field containing noise. The filtering process is controlled by the tensor field to be visualised, creating patterns that characterise the tensor field. By combining direct volume rendering of the scalar field with standard glyph rendering methods for detailed tensor visualisation, a hybrid solution is created.

    A combined volume and glyph renderer was implemented and tested with both synthetic tensors and strain-rate tensors from the human heart muscle, calculated from phase contrast magnetic resonance image data. A comprehensible result could be obtained, giving both an overview of the tensor field as well as detailed information on individual tensors.

  • 209.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Escobar Kvitting, John-Peder
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Wigström, Lars
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    5D MRI - Cardiac and respiratory time-resolved volume imaging2004Inngår i: Proceedings of the annaual conference of the European Society for Magnetic Resonance in Medicine and Biology, 2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Respiratory motion is often a source of artifacts in cardiovascular imaging, but may also convey important physiological information. To improve our understanding

  • 210.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Escobar Kvitting, John-Peder
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Wigström, Lars
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Andersson, Mats
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Retrospective Respiratory Motion Compensation for Cardiac MRI2003Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Cardiac MRI is known to be degraded by respiratory motion. Short scans can be performed using breath-hold techniques, while coronary artery imaging commonly use navigator gated sequences, acquiring data in a known static respiration position.

  • 211.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Escobar Kvitting, John-Peder
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Thorax-kärlkliniken.
    Wigström, Lars
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    k-t2 BLAST: Exploiting spatiotemporal structure in simultaneous cardiac and respiratory resolved volume imaging2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Multidimensional imaging resolving both the cardiac and respiratory cycles simultaneously has the potential to describe important physiological interdependences between the heart and pulmonary processes. A fully five-dimensional acquisition with three spatial and two temporal dimensions is hampered, however, by the long acquisition time and low spatial resolution. A technique is proposed to reduce the scan time substantially by extending the k-t BLAST framework to two temporal dimensions. By sampling the k-t space sparsely in a lattice grid, the signal in the transform domain, x-f space, can be densely packed, exploiting the fact that large regions in the field of view have low temporal bandwidth. A volumetric online prospective triggering approach with full cardiac and respiratory cycle coverage was implemented. Retrospective temporal interpolation was used to refine the timing estimates for the center of k-space, which is sampled for all cardiac and respiratory time frames. This resulted in reduced reconstruction error compared with conventional k-t BLAST reconstruction. The k-t2 BLAST technique was evaluated by decimating a fully sampled five-dimensional data set, and feasibility was further demonstrated by performing sparsely sampled acquisitions. Compared to the fully sampled data, a fourfold improvement in spatial resolution was accomplished in approximately half the scan time.

  • 212.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Estepar, R.
    E.T.S.I. Telecomunicaci´on, University of Valladolid, Spain.
    Wigström, Lars
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Alberola, C.
    E.T.S.I. Telecomunicaci´on, University of Valladolid, Spain.
    Westin, C-F.
    Brigham and Women’s Hospital, Harvard Medical School, Boston.
    Diffusion tensor visualization using random field correlation and volume rendering2003Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The visualization of diffusion tensor fields remains a challenging topic. A representation based on volume rendering of a scalar field is presented. The method uses the tensor to correlate a noise field in the direction of greater diffusivity while preserving the high frequency components of the noise field in transversal diffusion directions.

  • 213.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Haraldsson, Henrik
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Knutsson, Hans
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Sakuma, Hajima
    Mie University, Japan.
    SNR evaluation of 32 channel cardiac coils in DENSE MRI at 1.5 and 3T2010Inngår i: ISMRM 2010, International Society for Magnetic Resonance in Medicine ( ISMRM ) , 2010Konferansepaper (Annet vitenskapelig)
  • 214.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Haraldsson, Henrik
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Ebbers, Tino
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Fysiologi. Linköpings universitet, Hälsouniversitetet.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet.
    Sakuma, Hajime
    Radiology, Mie University, Japan.
    In-vivo SNR in DENSE MRI: temporal and regional effects of field strength, receiver coil sensitivity, and flip angle strategies2011Inngår i: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 29, nr 2, s. 202-208Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: The influences on the SNR of DENSE MRI of field strength, receiver coil sensitivity and choice of flip angle strategy have been previously investigated individually. In this study, all of these parameters have been investigated in the same setting, and a mutual comparison of their impact on SNR is presented.

    Materials and methods: Ten healthy volunteers were imaged in a 1.5T and a 3T MRI system, using standard 5 or 6 channel cardiac coils as well as 32 channel coils, with four different excitation patterns. Variation of spatial coil sensitivity was assessed by regional SNR analysis.

    Results: SNR ranging from 2.8 to 30.5 was found depending on the combination of excitation patterns, coil sensitivity and field strength. The SNR at 3T was 53 ± 26% higher than at 1.5T (p<0.001), whereas spatial differences of 59 ± 26% were found in the ventricle (p<0.001). 32 channel coils provided 52 ± 29% higher SNR compared to standard 5 or 6 channel coils (p<0.001). A fixed flip angle strategy provided an excess of 50% higher SNR in half of the imaged cardiac cycle compared to a sweeping flip angle strategy, and a single phase acquisition provided a six-fold increase of SNR compared to a cine acquisition.

    Conclusion: The effect of field strength and receiver coil sensitivity influences the SNR with the same order of magnitude, whereas flip angle strategy can have a larger effect on SNR. Thus, careful choice of imaging hardware in combination with adaptation of the acquisition protocol is crucial in order to realize sufficient SNR in DENSE MRI.

  • 215.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Haraldsson, Henrik
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Ebbers, Tino
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Knutsson, Hans
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Sakuma, Hajime
    Radiology, Mie University, Japan.
    Single Breath Hold Multiple Slice DENSE MRI2010Inngår i: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 63, nr 5, s. 1411-1414Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A method to acquire multiple displacement encoded slices within asingle breath hold is presented. Efficiency is improved overconventional Displacement ENcoding with Stimulated Echoes (DENSE) without compromising image quality by read-out of multiple slices inthe same cardiac cycle, thus utilizing the position encoded stimulatedecho available in the whole heart. The method was evaluated bycomparing strain values obtained using the proposed method to strainvalues obtained by conventional separate breath hold single-sliceDENSE acquisitions. Good agreement (Lagrangian E2 strainbias=0.000, 95% limits of agreement ±0.04,root-mean-square-difference 0.02 (9.4% of the mean end-systolic E2)) was found between the methods, indicating that the proposedmethod can replace a multiple breath hold acquisition. Eliminating theneed for multiple breath holds reduces the risk of changes in breathhold positions or heart rate, results in higher patient comfort andfacilitates inclusion of DENSE in a clinical routine protocol.

  • 216.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Haraldsson, Henrik
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Takase, S.
    Mie University, Tsu, Mie, Japan.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Sakuma, H.
    Mie University, Tsu, Mie, Japan.
    Flip Angle Strategies for Multiphase DENSE2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In multiphase DENSE MRI, available signal decreases during the cardiac cycle due to excitation and T1-relaxation. Because of this, a widely used method is to vary the flip angle to yield constant SNR during the cardiac cycle. Unfortunately, this may lead to significant sacrifices of SNR in the early cardiac phases.

  • 217.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    Haraldsson, Henrik
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Takase, S.
    Mie University, Tsu, Mie, Japan.
    Sakuma, H.
    Mie University, Tsu, Mie, Japan.
    Multi Slice DENSE in a Single Breath Hold2009Konferansepaper (Fagfellevurdert)
  • 218.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Kvitting, John-Peder Escobar
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Thorax-kärlkliniken. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Wigström, Lars
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Five-dimensional MRI Incorporating Simultaneous Resolution of Cardiac and Respiratory Phases for Volumetric Imaging2006Inngår i: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 25, nr 1, s. 113-121Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose

    To develop a new volumetric imaging method resolved over both the cardiac and respiratory cycles, to enable future physiological and pathophysiological studies of respiratory-related cardiac motion.

    Materials and Methods

    An acquisition scheme is proposed whereby the k-space acquisition order is controlled in real-time by the current cardiac and respiratory phases. To reduce eddy-current effects induced by sudden jumps in k-space, the acquisition order is further optimized by the use of a Hilbert curve trajectory in the ky-kz plane. A complete three-dimensional (3D) k-space is acquired for all combinations of cardiac and respiratory phases, yielding a five-dimensional (5D) data set after retrospective reconstruction.

    Results

    Left (LV) and right ventricular (RV) wall excursion was measured in a healthy volunteer. Diastolic LV diameter was shown to increase during expiration and decrease during inspiration, as expected from previous echocardiography studies. The LV volume was estimated for all cardiac and respiratory phases with the use of a fully 3D segmentation tool. The results confirmed that the diastolic LV volume increased during expiration and decreased during inspiration.

    Conclusion

    With its ability to measure motion anywhere in the heart, the described technique provides a promising approach for in-depth description of interventricular coupling, including 3D ventricular volumes, during both the cardiac and respiratory cycles.

  • 219.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Petersson, Sven
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet.
    Carlhäll, Carljohan
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Ebbers, Tino
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Four-dimensional flow MRI using spiral acquisition2012Inngår i: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 68, nr 4, s. 1065-1073Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Time-resolved three-dimensional phase-contrast MRI is an important tool for physiological as well as clinical studies of blood flow in the heart and vessels. The application of the technique is, however, limited by the long scan times required. In this work, we investigate the feasibility of using spiral readouts to reduce the scan time of four-dimensional flow MRI without sacrificing quality. Three spiral approaches are presented and evaluated in vivo and in vitro against a conventional Cartesian acquisition. In vivo, the performance of each method was assessed in the thoracic aorta in 10 volunteers using pathline-based analysis and cardiac output analysis. Signal-to-noise ratio and background phase errors were investigated in vitro. Using spiral readouts, the scan times of a four-dimensional flow acquisition of the thoracic aorta could be reduced 23-fold, with no statistically significant difference in pathline validity or cardiac output. The shortened scan time improves the applicability of four-dimensional flow MRI, which may allow the technique to become a part of a clinical workflow for cardiovascular functional imaging.

  • 220.
    Sigfridsson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken. Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Hälsouniversitetet.
    Wigström, Lars
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken. Linköpings universitet, Hälsouniversitetet.
    Kvitting, John-Peder Escobar
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och vård, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet.
    Knutsson, Hans
    Linköpings universitet, Institutionen för medicinsk teknik, Medicinsk informatik. Linköpings universitet, Tekniska högskolan.
    k-t2 BLAST: Exploiting spatiotemporal structure in simultaneously cardiac and respiratory time-resolved volumetric imaging2007Inngår i: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 58, nr 5, s. 922-930Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Multidimensional imaging resolving both the cardiac and respiratory cycles simultaneously has the potential to describe important physiological interdependences between the heart and pulmonary processes. A fully five-dimensional acquisition with three spatial and two temporal dimensions is hampered, however, by the long acquisition time and low spatial resolution. A technique is proposed to reduce the scan time substantially by extending the k-t BLAST framework to two temporal dimensions. By sampling the k-t space sparsely in a lattice grid, the signal in the transform domain, x-f space, can be densely packed, exploiting the fact that large regions in the field of view have low temporal bandwidth. A volumetric online prospective triggering approach with full cardiac and respiratory cycle coverage was implemented. Retrospective temporal interpolation was used to refine the timing estimates for the center of k-space, which is sampled for all cardiac and respiratory time frames. This resulted in reduced reconstruction error compared with conventional k-t BLAST reconstruction. The k-t2 BLAST technique was evaluated by decimating a fully sampled five-dimensional data set, and feasibility was further demonstrated by performing sparsely sampled acquisitions. Compared to the fully sampled data, a fourfold improvement in spatial resolution was accomplished in approximately half the scan time.

  • 221.
    Silén, Charlotte
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi.
    The tutor's approach in base groups (PBL)2006Inngår i: Higher Education, ISSN 0018-1560, E-ISSN 1573-174X, Vol. 51, nr 3, s. 373-385Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    In this article, the concept of approach related to tutor functioning in problem-based learning (PBL) is explored and the significance of a phenomenological perspective of the body in relation to learning and tutoring is investigated. The aim has been to understand the concept of approach in a context where the individual, thoughts, emotions and body are regarded as a whole in a learning process - a non-dualistic entity. The analysis is primarily based on Merleau-Ponty (Phenomenologie de la Perception. Editions Gallimard, Kroppens fenomenologi. Oslo: Pax) and Leder (1990). The outcome of the analysis is related to the pedagogical view that characterises PBL and tutoring in base groups. An earlier study (Silén Licentiate thesis n 3/1996. Linköping University) about tutor functioning in PBL was the starting-point for the exploration. On the basis of the phenomenological analysis, I assign approach the following meaning: - the total message expressed by 'the lived body' in interaction with its life world. The analysis indicates that the tutor's approach influences group work in different ways. One of phenomenology's most important messages implies that the tutor's approach should be characterised by 'presence', attention on the students and what is happening in the group, and not on the tutor's own actions and thoughts. The ability to be 'present' is possible when the knowing is rooted in the lived body. This conclusion brings to the fore the necessity of the tutor's own understanding of the ideas of PBL and the underlying theories, and also highlights the importance of regarding tutor training as an ongoing learning process. The focus of the exploration has been on the tutor in PBL. In principle, I would argue that a corresponding line of reasoning is applicable to tutoring and learning in general. © Springer 2006.

  • 222.
    Silén, Charlotte
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Wirell, Staffan
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping. Linköpings universitet, Hälsouniversitetet.
    Kvist, Joanna
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för sjukgymnastik. Linköpings universitet, Hälsouniversitetet.
    Nylander, Eva
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Fyrénius, Anna
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Östergötlands Läns Landsting, Bildmedicinskt centrum, Röntgenkliniken i Linköping. Linköpings universitet, Hälsouniversitetet.
    Advanced 3D visualization in student-centred medical education2008Inngår i: Medical teacher, ISSN 0142-159X, E-ISSN 1466-187X, Vol. 30, nr 5, s. e115-e124Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Healthcare students have difficulties achieving a conceptual understanding of 3D anatomy and misconceptions about physiological phenomena are persistent and hard to address. 3D visualization has improved the possibilities of facilitating understanding of complex phenomena. A project was carried out in which high quality 3D visualizations using high-resolution CT and MR images from clinical research were developed for educational use. Instead of standard stacks of slices (original or multiplanar reformatted) volume-rendering images in the quicktime VR format that enables students to interact intuitively were included. Based on learning theories underpinning problem based learning, 3D visualizations were implemented in the existing curricula of the medical and physiotherapy programs. The images/films were used in lectures, demonstrations and tutorial sessions. Self-study material was also developed. AIMS: To support learning efficacy by developing and using 3D datasets in regular health care curricula and enhancing the knowledge about possible educational value of 3D visualizations in learning anatomy and physiology. METHOD: Questionnaires were used to investigate the medical and physiotherapy students' opinions about the different formats of visualizations and their learning experiences. RESULTS: The 3D images/films stimulated the students will to understand more and helped them to get insights about biological variations and different organs size, space extent and relation to each other. The virtual dissections gave a clearer picture than ordinary dissections and the possibility to turn structures around was instructive. CONCLUSIONS: 3D visualizations based on authentic, viable material point out a new dimension of learning material in anatomy, physiology and probably also pathophysiology. It was successful to implement 3D images in already existing themes in the educational programs. The results show that deeper knowledge is required about students' interpretation of images/films in relation to learning outcomes. There is also a need for preparations and facilitation principles connected to the use of 3D visualizations.

  • 223.
    Siwe, Karin
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Genus och medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Barn- och kvinnocentrum, Kvinnokliniken i Linköping.
    Wijma, Barbro
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Genus och medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Barn- och kvinnocentrum, Kvinnokliniken i Linköping.
    Silén, Charlotte
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Berterö, Carina
    Linköpings universitet, Institutionen för medicin och hälsa, Omvårdnad. Linköpings universitet, Hälsouniversitetet.
    Performing the First Pelvic Examination: Female Medical Students’ Transition to Examiners2007Inngår i: Patient Education and Counseling, ISSN 0738-3991, E-ISSN 1873-5134, Vol. 69, nr 1-3, s. 55-62Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objective: To gain a deeper understanding of how female medical students perceive and experience performing their first pelvic examination (PE).

    Methods: A qualitative study. In-depth interviews after the students’ involvement in a learning session about the PE, with professional patients (PPs) as instructors and a gynaecologist as supervisor. The interviews were analysed according to the constant comparative method to acquire a deeper understanding of the students’ experiences and the ongoing social processes.

    Results: “Transcending unspoken boundaries and taboos, a prerequisite for learning” was the essence of the entire material and was identified from two categories: “A didactic design facilitates the transition to examiner” and “Interactive support enables creative learning of interpersonal and palpation skills”.

    Conclusion: Through interactive guidance from the PPs, the students overcame affective obstacles and achieved the aim of becoming an examiner. The favourable learning experience heightened their awareness of their own bodies and promoted a deeper interest in PEs, both as examiners and as patients.

    Practice implications: Engaging voluntary, healthy and knowledgeable women as instructors in the PE situation creates a safe learning environment and promotes interaction with students. Immediate feedback teaches students to integrate communicative and behavioural skills in a professional manner and to palpate the uterus.

  • 224.
    Sjöberg, Birgitta Janero
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik. Linköpings universitet, Tekniska högskolan.
    Loyd, Dan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska högskolan.
    Wranne, Bengt
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Subaortic flow profiles in aortic valve disease: a two-dimensional color Doppler study.1994Inngår i: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 7, nr 3 Pt 1, s. 276-285Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    With time-corrected color Doppler echocardiography, the aortic subvalvular spatial flow velocity profile was registered in two perpendicular planes in 10 patients with aortic valve disease and in 5 healthy control subjects. Patients with predominant aortic valve stenosis had a fairly flat profile, and the subvalvular diameter, obtained from left parasternal two-dimensional tissue imaging, provided a good estimate of the mean of the two transverse flow axes. This explains the accuracy in determination of stroke volume and aortic valve area that is reported in studies on patients with aortic valve stenosis when the continuity equation is used. However, the use of apical pulsed Doppler ultrasound registrations from the left ventricular outflow tract and parasternal two-dimensional echocardiography for flow area calculation may introduce large errors in calculated stroke volume in certain patients with aortic regurgitation and in normal subjects, because of a non-flat spatial velocity profile or an inaccurate estimate of flow area.

  • 225.
    Sjöberg, Birgitta Janero
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Eidenvall, L
    Loyd, Dan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska högskolan.
    Wranne, Bengt
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik. Linköpings universitet, Tekniska högskolan.
    Vascular characteristics influence the aortic ultrasound Doppler signal: computer and hydraulic model simulations.1993Inngår i: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 147, nr 3, s. 271-279Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is an increasing demand for non-invasive methods for the assessment of left ventricular function. Ultrasound Doppler methods are promising, and the early systolic flow velocity signal immediately distal to the aortic valve has been used clinically for this purpose. However, the signal is influenced not only by left ventricular ejection but also by systemic vascular characteristics. Their relative contribution to the time-velocity signal has not been analysed in depth previously. A theoretical analysis, based on a three-element Windkessel model, neglecting peripheral outflow in early systole and assuming linear pressure rise, was therefore tested in computer and hydraulic model simulations where peripheral outflow was included. Significant changes in early aortic flow velocity parameters were found when vascular characteristics were altered. As predicted by the theory, with a standardized aortic valve area and aortic pressure change, the simulations confirmed that maximal flow velocity is related to compliance of the aorta and the large arteries, and that maximal acceleration is inversely related to the characteristic impedance of the aorta. Therefore, maximal velocity and acceleration can be used for assessment of left ventricular function only in situations where vascular characteristics can be considered relatively constant or where they can be estimated.

  • 226.
    Sjöblom, Peter
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Hälsouniversitetet.
    Engvall, Jan
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Länne, Toste
    Linköpings universitet, Institutionen för medicin och hälsa, Fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Thorax-kärlkliniken.
    Nyström, Fredrik
    Linköpings universitet, Institutionen för medicin och hälsa, Internmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Medicincentrum, Endokrin- och magtarmmedicinska kliniken US.
    Östgren, Carl Johan
    Linköpings universitet, Institutionen för medicin och hälsa, Allmänmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i Finspång, Vårdcentralen.
    Microalbuminuria but not reduced GFR is a marker of subclinical atherosclerosis and arterial stiffness in type 2 diabetes in DIABETOLOGIA, vol 53, issue , pp2010Inngår i: DIABETOLOGIA, Springer Science Business Media , 2010, Vol. 53Konferansepaper (Fagfellevurdert)
    Abstract [en]

    n/a

  • 227.
    Stratelis, Georgios
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Allmänmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i västra Östergötland, Primärvården i västra länsdelen.
    Fransson, Sven Göran
    Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Schmekel, Birgitta
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Jakobsson, Per
    Linköpings universitet, Institutionen för medicin och hälsa, Lungmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Lungmedicinska kliniken US.
    Mölstad, Sigvard
    Linköpings universitet, Institutionen för medicin och hälsa, Allmänmedicin. Linköpings universitet, Hälsouniversitetet.
    High prevalence of emphysema and its association with BMI: A study of smokers with normal spirometry2008Inngår i: Scandinavian Journal of Primary Health Care, ISSN 0281-3432, E-ISSN 1502-7724, Vol. 26, nr 4, s. 241-247Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives: To evaluate to what extent emphysema was evident, as identified by High Resolution Computed Tomography (HRCT), in smokers with normal lung function and to relate age, gender, smoking history, and body mass index (BMI) to the HRCT results. A secondary aim was to study to what extent emphysema was present in smokers with lower normal values of lung function defined as FEV1/FVC ratio percentage of predicted value (89-93% of predicted value for males and 90-93% for females) or FEF50 60% of predicted compared with smokers without this definition.

    Methods: Fifty-nine smokers, with a mean age of 53 years and with normal lung function, were examined with HRCT.

    Results: Emphysema evidenced visually by HRCT was present in 43% of the subjects. Using a 0-5 grade scale (0=normal finding; 5=emphysema in most slices), the degree of emphysema was almost exclusively 3-4. The type of emphysema was distributed as centrilobular emphysema predominant in 43.5%, paraseptal emphysema predominant in 43.5%, and as an equal mixture of these types in 13%. The presence of emphysema did not differ between the group of smokers with lower normal values of lung function and the rest of the smokers. Smokers with emphysema had significantly lower BMI than those devoid of emphysema, 24 and 27 respectively (p0.0011).

    Conclusion: There was a high occurrence of visual emphysema in middle-aged smokers with normal lung function. The densitometric quantitative analysis method is inadequate for detecting mild emphysema. High prevalence of emphysema was associated with low BMI.

  • 228.
    Strotmann, J. M.
    et al.
    Östergötlands Läns Landsting, Hjärtcentrum.
    Janerot Sjöberg, Birgitta
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum.
    Kimme, Peter
    Linköpings universitet, Institutionen för medicin och vård, Anestesiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Anestesi- och operationscentrum, Intensivvårdskliniken US.
    Fröhlich, B.
    University of Heidelberg.
    Voight, J-U.
    Östergötlands Läns Landsting, Hjärtcentrum.
    Schreckenberger, A. B.
    Östergötlands Läns Landsting, Hjärtcentrum.
    Hatle, L.
    Östergötlands Läns Landsting, Hjärtcentrum.
    Sutherland, G. R.
    Östergötlands Läns Landsting, Hjärtcentrum.
    The effect of pacing-induced heart rate variation on longitudinal and circumferential regional myocardial function after acute beta-blockade a cardiac ultrasound study2000Inngår i: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 1, nr 3, s. 184-195Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aims: To evaluate the effect of acute beta-blockade in combination with differing heart rates on longitudinal and circumferential regional myocardial function using Doppler myocardial imaging and two-dimensional-echocardiography.

    Methods and Results: In seven pigs the following echocardiographic indices were measured at baseline, after beta-blockade both without and with atrial pacing: wall thickening fraction, fractional shortening, myocardial peak systolic velocity, transmyocardial velocity gradient and systolic velocity time integral of the posterolateral wall in short-axis view; mitral valve plane excursion, myocardial peak systolic velocity and systolic velocity time integral of the posterolateral wall in an apical five-chamber view. Peak systolic velocities and velocity gradients decreased significantly following acute beta-blockade but no further decay occurred at high heart rate due to pacing. The velocity time integrals and mitral valve plane excursion showed a tendency to decrease following beta-blockade but only after pacing were they significantly reduced. The wall thickening fraction and fractional shortening showed a significant reduction after beta-blockade but no further decay after pacing.

    Conclusions: Changes in systolic velocities and velocity gradients were independent of heart rate reduction under high dosage beta-blockade, whereas wall thickening fraction, mitral valve plane excursion and velocity time integrals changed due to pacing.

  • 229. Strotmann, J.M.
    et al.
    Richter, Arina
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Kukulski, T.
    Voigt, J.-U.
    Fransson, Sven Göran
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Wranne, Bengt
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Hatle, L.
    Sutherland, G.R.
    Doppler myocardial imaging in the assessment of regional myocardial function in longitudinal direction pre- and post-PTCA2001Inngår i: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 2, nr 3, s. 178-186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aims: Doppler myocardial imaging is potentially a sensitive tool to assess regional myocardial velocities pre- and post-percutaneous transluminal coronary angioplasty (PTCA) as a marker of contractility to evaluate short- to medium-term information on functional myocardial recovery following the release of ischaemia. Methods: Thirty patients with single vessel disease were studied to assess regional myocardial peak systolic velocity, systolic velocity time integral and mitral valve plane excursion in longitudinal direction one day pre-, one day post- and 3 months post-PTCA. The patients were assigned to group A with coronary stenoses >70% and group B with stenoses <70%. Results: In group A pre-PTCA the ischaemic segments showed a significantly lower peak systolic velocity and velocity time integral compared with the values one day after PTCA (5.8 ± 1.4 vs 7.7 ± 1.4 cm.s-1, 1.06 ± 0.22 vs 1.23 ± 0.28 cm, P< 0.03). In contrast, mitral valve plane excursion in this group remained unchanged after PTCA for both the ischaemic and non-ischaemic left ventricular wall. In group B no changes of these parameters and no differences in mitral valve plane excursion of the ischaemic and the non-ischaemic left ventricular wall could be seen. Conclusion: With Doppler myocardial imaging it was possible to quantify a number of indices which changed due to the successful release of ischaemia.© 2001 The European Society of Cardiology.

  • 230. Sun, Y
    et al.
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik. Linköpings universitet, Tekniska högskolan.
    Sjöberg, Birgitta Janero
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Eidenvall, L
    Loyd, Dan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska högskolan.
    Wranne, Bengt
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Estimation of volume flow rate by surface integration of velocity vectors from color Doppler images.1995Inngår i: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 8, nr 6, s. 904-914Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new Doppler echocardiographically based method has been developed to quantify volume flow rate by surface integration of velocity vectors (SIVV). Electrocardiographic-gated color Doppler images acquired in two orthogonal planes were used to estimate volume flow rate through a bowl-shaped surface at a given time and distance from the probe. To provide in vitro validation, the method was tested in a hydraulic model representing a pulsatile flow system with a restrictive orifice. Accurate estimates of stroke volume (+/- 10%) were obtained in a window between 1.2 and 1.6 cm proximal to the orifice, just before the region of prestenotic acceleration. By use of the Bernoulli's equation, the estimated flows were used to generate pressure gradient waveforms across the orifice, which agreed well with the measured flows. To demonstrate in vivo applicability, the SIVV method was applied retrospectively to the determination of stroke volume and subaortic flow from the apical three-chamber and five-chamber views in two patients. Stroke volume estimates along the left ventricular outflow tract showed a characteristic similar to that in the in vitro study and agreed well with those obtained by the Fick oxygen method. The region where accurate measurements can be obtained is affected by instrumental factors including Nyquist velocity limit, wall motion filter cutoff, and color flow sector angle. The SIVV principle should be useful for quantitative assessment of the severity of valvular abnormalities and noninvasive measurement of pulsatile volume flows in general.

  • 231. Sun, Y
    et al.
    Sjöberg, Birgitta Janero
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik. Linköpings universitet, Tekniska högskolan.
    Loyd, Dan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska högskolan.
    Wranne, Bengt
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Mathematical model that characterizes transmitral and pulmonary venous flow velocity patterns.1995Inngår i: American Journal of Physiology, ISSN 0002-9513, E-ISSN 2163-5773, Vol. 268, nr 1 Pt 2, s. H476-89Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The transmitral and pulmonary venous flow velocity (TMFV and PVFV, respectively) patterns are related to the physiological state of the left heart by use of an electrical analog model. Filling of left ventricle (LV) through the mitral valve is characterized by a quadratic Bernoulli's resistance in series with an inertance. Filling of the left atrium (LA) through the pulmonary veins is represented by a lumped network of linear resistance, capacitance, and inertance. LV and LA are each represented by a time-varying elastance. A volume dependency is incorporated into the LV model to produce physiological pressure-volume loops and Starling curves. The state-space representation of the analog model consists of 10 simultaneous differential equations, which are solved by numerical integration. Model validity is supported by the following. First, the expected effects of aging and decreasing LV compliance on TMFV and PVFV are accurately represented by the model. Second, the model-generated TMFV and PVFV waveforms fit well to pulsed-Doppler recordings in normal and postinfarct patients. It is shown that the TMFV deceleration time is prolonged by the increase in LV compliance and, to a lesser extent, by the increase in LA compliance. A shift from diastolic dominance to systolic dominance in PVFV occurs when LA compliance or pulmonary perfusion pressure increases or when LV compliance or mitral valve area decreases. The present model should serve as a useful theoretical basis for echocardiographic evaluation of LV and LA functions.

  • 232. Sun, Ying
    et al.
    Ask, Per
    Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik. Linköpings universitet, Tekniska högskolan.
    Sjöberg, Birgitta Janero
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Eindvall, Lars
    Loyd, Dan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska högskolan.
    Wranne, Bengt
    Linköpings universitet, Institutionen för medicin och vård, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Estimation of volume flow rate by surface integration of velocity vectors from color Doppler images1997Inngår i: Journal of the American College of Cardiology, ISSN 0735-1097, E-ISSN 1558-3597, Vol. 8, nr 6, s. 904-914Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new Doppler echocardiographically based method has been developed to quantify volume flow rate by surface integration of velocity vectors (SIVV). Electrocardiographic-gated color Doppler images acquired in two orthogonal planes were used to estimate volume flow rate through a bowl-shaped surface at a given time and distance from the probe. To provide in vitro validation, the method was tested in a hydraulic model representing a pulsatile flow system with a restrictive orifice. Accurate estimates of stroke volume (±10%) were obtained in a window between 1.2 and 1.6 cm proximal to the orifice, just before the region of prestenotic acceleration. By use of the Bernoulli's equation, the estimated flows were used to generate pressure gradient waveforms across the orifice, which agreed well with the measured flows. To demonstrate in vivo applicability, the SIVV method was applied retrospectively to the determination of stroke volume and subaortic flow from the apical three-chamber and five-chamber views in two patients. Stroke volume estimates along the left ventricular outflow tract showed a characteristic similar to that in the in vitro study and agreed well with those obtained by the Fick oxygen method. The region where accurate measurements can be obtained is affected by instrumental factors including Nyquist velocity limit, wall motion filter cutoff, and color flow sector angle. The SIVV principle should be useful for quantitative assessment of the severity of valvular abnormalities and noninvasive measurement of pulsatile volume flows in general.

  • 233. Sundblad, P
    et al.
    Wranne, Bengt
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Influence of posture on left ventricular long- and short-axis shortening2002Inngår i: American Journal of Physiology. Heart and Circulatory Physiology, ISSN 0363-6135, E-ISSN 1522-1539, Vol. 283, nr 4, s. H1302-H1306Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    End-diastolic volume and left ventricular stroke volume are increased in the supine compared with upright position, but the contribution of long-axis (LAS) and short-axis shortening (SAS) to these changes with change in posture has not been established. We examined long- and short-axis motion and dimensions with echocardiography in 10 healthy subjects in the upright and supine position. Long-axis length at end diastole was almost identical, whereas the diastolic short-axis diameter was increased in the supine position. At end systole, there was a decreased long- axis length and increased short-axis length in the supine vs. upright position. Both LAS and SAS were enhanced in supine vs. upright positions [LAS: 9.3 +/- 2.2 vs. 15.1 +/- 3.1 mm (P < 0.001), SAS: 12.7 +/- 3.2 vs. 16.3 +/- 2.8 mm (P < 0.001)], presumably via Starling mechanisms. LAS increased more in the lateral part of the mitral annulus than in the septal part [7.7 +/- 2.6 vs. 4.0 +/- 2.8 mm (P < 0.006)], which implies that the more spherical form, in the supine position, induces more stretch at the lateral free wall than in the ventricular septum. These findings support the notion that Starling mechanisms affect systolic LAS.

  • 234.
    Sund-Levander, Märtha
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Measurement and evaluation of body temperature: Implications for clinical practice2004Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The general aim was to explore factors influencing the normal variation and measurement of body temperature. Additional aims were to study morbidity, mortality and the clinical presentation of pneumonia and predictors for survival in elderly nursing-home residents. Two hundred and thirty seven non-febrile nursing home residents (aged 66-99 years) and 87 healthy adults (aged 19-59 years) were included. In elderly individuals, the morning ear and rectal body temperature was measured at baseline and pneumonia and survival was observed at one- two and three-year. In healthy adults the rectal, ear, oral and axillary temperature were measured simultaneously on one morning and repeated measurements were performed in three subjects.

    Overall, the range of normal body temperature was wider then traditionally stated. In elderly nursinghome residents, functional and cognitive impairment and BMI < 20 were related to a lower body temperature and medication with analgesics to a higher. Compared to adults < 60 years elderly persons had a higher average ear and a lower rectal temperature. Men and postmenopausal women < 60 years had lower body temperature than premenopausal women. The repeated measurements showed a wide individual variability irrespective of the site of measurement, and that replicated measurements do not improve accuracy. When comparing the rectal temperature with oral, ear and axillary readings the average difference was > 0.5°C with a wide individual variation.

    The yearly incidence of nursing-home acquired pneumonia varied between 6.9% and 13.7%. Functional impairment, chronic obstructive pulmonary disease (COPD) and male sex were related to a higher risk of acquiring pneumonia and presenting non-specific symptoms were common. Age and functional impairment predicted mortality, irrespective of gender, while cerebral vascular insult, a lower body mass index and malnutrition in women and heart disease, COPD, medication with sedatives and mortality rate index in men were gender specific predictors. Surviving women had a higher baseline body temperature than non-surviving, while no such difference was found in men.

    When assessing body temperature, it is important to consider the site of measurement, technical design, operator technique, age and gender and, in elderly nursing-home residents, physical and cognitive impairment, body constitution and medication with analgesics. The best approach is to use an unadjusted mode, without adjusting to another site. To prevent a delayed diagnosis of pneumonia, one should be aware of a low baseline body temperature and lack of specific clinical symptoms in elderly nursing-home residents. Preserving and/or improving functional, cognitive, nutritional status and preventing agitation and confusion would improve survival in nursing-home residents.

    Delarbeid
    1. The impact of ADL-status, dementia and body mass index on normal body temperature in elderly nursing home residents
    Åpne denne publikasjonen i ny fane eller vindu >>The impact of ADL-status, dementia and body mass index on normal body temperature in elderly nursing home residents
    2002 (engelsk)Inngår i: Archives of gerontology and geriatrics, ISSN 0167-4943, Vol. 35, nr 2, s. 161-169Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    A subset of seniors might demonstrate a lower body temperature compared with younger subjects. However, data on normal body temperature in seniors are sparse. The aim of the study was to study normal body temperature with a view of predicting factors of low body temperature in non-febrile seniors. Elderly women (n=159) and 78 men, aged ≥65 years, living in community resident homes were included in the study. Data on chronic diseases and medication were collected from medical records. Tympanic and rectal temperature was measured twice daily; once at 7–9 AM and then at 6–8 PM. In addition, body mass index (BMI), activities of daily living (ADL) status, as well as details regarding dementia and malnutrition were recorded. The variation in tympanic and rectal temperatures ranged from 33.8 to 38.4 °C and 35.6 to 38.0 °C, respectively. ADL status, dementia and BMI were significantly related to lower and analgesic to higher tympanic temperature. Dementia was significantly related to lower rectal temperature. Therefore, dementia, BMI, ADL status and analgesic shall not be overlooked when assessing temperature in seniors. More research is needed to further clarify the influence of these predictive factors, as well as the impact of BMI and malnutrition.

    Emneord
    Dementia, Activities of daily living status, Body mass index, Normal body temperature in elderly
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-13663 (URN)10.1016/S0167-4943(02)00019-5 (DOI)
    Tilgjengelig fra: 2004-12-19 Laget: 2004-12-19 Sist oppdatert: 2009-06-04
    2. Errors in body temperature assessment related to individual variation, measuring technique and equipment
    Åpne denne publikasjonen i ny fane eller vindu >>Errors in body temperature assessment related to individual variation, measuring technique and equipment
    2005 (engelsk)Inngår i: International journal of nursing practice, ISSN 1322-7114, Vol. 10, nr 5, s. 216-223Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Errors in body temperature measurement might seriously influence the evaluation of an individual's health condition. We studied individual variation, measurement technique and the equipment used when assessing body temperature. In the first part of the study, three volunteers performed repeated measurements for five mornings. In the second part, the morning rectal, oral, ear and axillary temperatures were measured once in 84 men and women (19–59 years). The repeated measurements showed a daily temperature difference of 0.1–0.4°C in rectal and oral temperatures, 0.2°C−1.7°C in the ear and 0.1–0.9°C in the axillary temperatures. In the sample of 84 subjects, men and postmenopausal women had a lower mean body temperature compared to premenopausal women. The mean deviation between rectal temperature, and oral, ear and axillary temperatures, respectively, was > 0.5°C, with a large individual variation. In conclusion, in order to improve the evaluation of body temperature, the assessment should be based on the individual variation, the same site of measurement and no adjustment of oral, ear or axillary temperatures to the rectal site.

    Emneord
    body temperature, gender, individual variation, repeated measurements, standardized
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-13664 (URN)10.1111/j.1440-172X.2004.00483.x (DOI)
    Tilgjengelig fra: 2004-12-19 Laget: 2004-12-19 Sist oppdatert: 2009-06-04
    3. Morbidity, mortality and clinical presentation of nursing homeacquired pneumonia in a Swedish population
    Åpne denne publikasjonen i ny fane eller vindu >>Morbidity, mortality and clinical presentation of nursing homeacquired pneumonia in a Swedish population
    Vise andre…
    2003 (engelsk)Inngår i: Scandinavian journal of infectious diseases, ISSN 0036-5548, Vol. 35, nr 5, s. 306-310Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Pneumonia has been estimated to be the second most common infection in nursing-home residents. However, to the authors' knowledge, no such Swedish data are available. Therefore, this study investigated the incidence, risk factors, and 30 d case-fatality rate and clinical presentation of nursing home-acquired pneumonia (NHAP) in 234 nursing-home residents aged 66-99 y. Activities of daily living (ADL status), malnutrition and body mass index were measured at baseline. The residents were then followed prospectively during 1 y for symptoms and signs of pneumonia. Pneumonia was verified clinically and/or radiologically in 32 residents, corresponding to a yearly incidence of 13.7%. The 30 d case-fatality rate was 28%. Cough and sputum production were the most specific, and fever ≥38.0°C rectally and cognitive decline were the most common non-specific presenting symptoms. Chronic obstructive pulmonary disease, ADL status >5 and male gender were risk factors for acquiring pneumonia. In conclusion, NHAP is associated with high morbidity and mortality in Sweden. In order not to delay treatment, it is necessary to be aware that specific symptoms of pneumonia may be lacking in the clinical presentation in the nursing-home setting.

    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-13665 (URN)10.1080/00365540310008456 (DOI)
    Tilgjengelig fra: 2004-12-19 Laget: 2004-12-19 Sist oppdatert: 2009-08-21
    4. Gender differences in predictors for survival in elderly nursing-home residents: A 3-year follow-up
    Åpne denne publikasjonen i ny fane eller vindu >>Gender differences in predictors for survival in elderly nursing-home residents: A 3-year follow-up
    2007 (engelsk)Inngår i: Scandinavian Journal of Caring Sciences, ISSN 0283-9318, E-ISSN 1471-6712, Vol. 21, nr 1, s. 18-24Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    This study focus on predicting factors of survival possible to modify by nursing care, and the incidence and mortality rate of nursing-home-acquired pneumonia, allocated to 1, 2 and 3 years of follow ups. The residents consisted of 156 women and 78 men living in special housing for the elderly. Data on chronic disease and medication were obtained at baseline, and activities of daily living (ADL) status, nutritional status and body temperature were assessed. The incidence of pneumonia was noted prospectively for 1 year and retrospectively for the following 2 years. Predictive factors for survival were explored by Cox hazard regression analysis. The results showed that age, functional and cognitive impairment were predictors of mortality irrespective of gender, while poor nutritional status in women and chronic obstructive pulmonary disease, heart disease and medication with sedatives in men were gender-specific predictors. ADL correlated positively with dementia and negatively with S-albumin irrespective of gender, while malnutrition correlated positively with ADL in women and positively with chronic obstructive pulmonary disease in men. To promote the quality of daily living in elderly individuals, it is of importance to improve the capabilities in daily functions and nutritional status, especially in women with functional impairment, and to prevent anxiety particularly in men. The findings also clarify that pneumonia is as common as cerebral vascular insult and heart failure as cause of death in this population.

    Emneord
    activities of daily living, gender, malnutrition, nursing care, pneumonia, survival
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-13666 (URN)10.1111/j.1471-6712.2007.00431.x (DOI)
    Tilgjengelig fra: 2004-12-19 Laget: 2004-12-19 Sist oppdatert: 2017-12-13
  • 235.
    Sund-Levander, Märtha
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Grodzinsky, Ewa
    Linköpings universitet, Institutionen för medicin och hälsa, Allmänmedicin. Linköpings universitet, Hälsouniversitetet.
    Loyd, Dan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanisk värmeteori och strömningslära. Linköpings universitet, Tekniska högskolan.
    Wahren, Lis Karin
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier. Linköpings universitet, Hälsouniversitetet.
    Errors in body temperature assessment related to individual variation, measuring technique and equipment2005Inngår i: International journal of nursing practice, ISSN 1322-7114, Vol. 10, nr 5, s. 216-223Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Errors in body temperature measurement might seriously influence the evaluation of an individual's health condition. We studied individual variation, measurement technique and the equipment used when assessing body temperature. In the first part of the study, three volunteers performed repeated measurements for five mornings. In the second part, the morning rectal, oral, ear and axillary temperatures were measured once in 84 men and women (19–59 years). The repeated measurements showed a daily temperature difference of 0.1–0.4°C in rectal and oral temperatures, 0.2°C−1.7°C in the ear and 0.1–0.9°C in the axillary temperatures. In the sample of 84 subjects, men and postmenopausal women had a lower mean body temperature compared to premenopausal women. The mean deviation between rectal temperature, and oral, ear and axillary temperatures, respectively, was > 0.5°C, with a large individual variation. In conclusion, in order to improve the evaluation of body temperature, the assessment should be based on the individual variation, the same site of measurement and no adjustment of oral, ear or axillary temperatures to the rectal site.

  • 236.
    Sund-Levander, Märtha
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Wahren, Lis Karin
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier. Linköpings universitet, Hälsouniversitetet.
    The impact of ADL-status, dementia and body mass index on normal body temperature in elderly nursing home residents2002Inngår i: Archives of gerontology and geriatrics, ISSN 0167-4943, Vol. 35, nr 2, s. 161-169Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A subset of seniors might demonstrate a lower body temperature compared with younger subjects. However, data on normal body temperature in seniors are sparse. The aim of the study was to study normal body temperature with a view of predicting factors of low body temperature in non-febrile seniors. Elderly women (n=159) and 78 men, aged ≥65 years, living in community resident homes were included in the study. Data on chronic diseases and medication were collected from medical records. Tympanic and rectal temperature was measured twice daily; once at 7–9 AM and then at 6–8 PM. In addition, body mass index (BMI), activities of daily living (ADL) status, as well as details regarding dementia and malnutrition were recorded. The variation in tympanic and rectal temperatures ranged from 33.8 to 38.4 °C and 35.6 to 38.0 °C, respectively. ADL status, dementia and BMI were significantly related to lower and analgesic to higher tympanic temperature. Dementia was significantly related to lower rectal temperature. Therefore, dementia, BMI, ADL status and analgesic shall not be overlooked when assessing temperature in seniors. More research is needed to further clarify the influence of these predictive factors, as well as the impact of BMI and malnutrition.

  • 237.
    Sund-Levander, Märtha
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Wahren, Lis-Karin
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier. Linköpings universitet, Hälsouniversitetet.
    Hamrin, Elisabeth
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Linköpings universitet, Hälsouniversitetet.
    Nursing care in fever: Assessment and implementation1998Inngår i: Nordic Journal of Nursing Research & Clinical Studies /Vård i Norden, ISSN 0107-4083, Vol. 18, nr 2, s. 27-30Artikkel i tidsskrift (Fagfellevurdert)
  • 238.
    Sund-Levander, Märtha
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Örtqvist, Åke
    Department of Communicable Diseases and Prevention, Stockholm County, Stockholm.
    Grodzinsky, Ewa
    Linköpings universitet, Institutionen för medicin och hälsa, Allmänmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i västra Östergötland, Forsknings- och utvecklingsenheten för Närsjukvården i Östergötland.
    Klefsgård, Örjan
    Department of Radiology, Högland Hospital, Eksjö.
    Wahren, Lis Karin
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier. Linköpings universitet, Hälsouniversitetet.
    Morbidity, mortality and clinical presentation of nursing homeacquired pneumonia in a Swedish population2003Inngår i: Scandinavian journal of infectious diseases, ISSN 0036-5548, Vol. 35, nr 5, s. 306-310Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pneumonia has been estimated to be the second most common infection in nursing-home residents. However, to the authors' knowledge, no such Swedish data are available. Therefore, this study investigated the incidence, risk factors, and 30 d case-fatality rate and clinical presentation of nursing home-acquired pneumonia (NHAP) in 234 nursing-home residents aged 66-99 y. Activities of daily living (ADL status), malnutrition and body mass index were measured at baseline. The residents were then followed prospectively during 1 y for symptoms and signs of pneumonia. Pneumonia was verified clinically and/or radiologically in 32 residents, corresponding to a yearly incidence of 13.7%. The 30 d case-fatality rate was 28%. Cough and sputum production were the most specific, and fever ≥38.0°C rectally and cognitive decline were the most common non-specific presenting symptoms. Chronic obstructive pulmonary disease, ADL status >5 and male gender were risk factors for acquiring pneumonia. In conclusion, NHAP is associated with high morbidity and mortality in Sweden. In order not to delay treatment, it is necessary to be aware that specific symptoms of pneumonia may be lacking in the clinical presentation in the nursing-home setting.

  • 239.
    Tamás, Éva
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet.
    Broqvist, Mats
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet.
    Olsson, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Franzén, Stefan
    Linköpings universitet, Institutionen för medicin och hälsa, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Thorax-kärlkliniken.
    Nylander, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Exercise radionuclide ventriculography for predicting postoperative left ventricular function in chronic aortic regurgitation2009Inngår i: JACC: Cardiovascular Imaging, ISSN 1936-878X, Vol. 2, nr 1, s. 48-55Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives: Ejection fraction (EF) reaction upon exercise by radionuclide ventriculography and standard echocardiographic parameters was evaluated as predictors for post-operative left ventricular (LV) function in chronic aortic regurgitation (AR).

    Background: The optimal timing of surgery for chronic AR is when the left ventricle is still compensating for the volume and pressure overload without irreversible dysfunction. For asymptomatic patients when EF is normal and LV diameters are borderline, exercise testing is recommended by present guidelines. However, only a limited number of studies have been performed, and data are scarce on this subject.

    Methods: Radionuclide ventriculography with multiple gated acquisition at rest and during exercise was performed in 29 consecutive patients with severe chronic aortic regurgitation pre-operatively and 6 months post-operatively. Patient subgroups were formed based on pre-operative EF exercise response (ΔEF) and were categorized as decreasing (ΔEF <−5%), unaltered (−5% ≤ ΔEF ≤ 5%), and increasing (ΔEF > 5%). A 5% or higher increase was considered normal. The LV diameters and mass were measured by echocardiography.

    Results: Pre-operative LV diameters were markedly elevated before surgery and diminished significantly after surgery. Left ventricular diameters, LV mass, EF at rest (EFrest), and EF change from rest to exercise (ΔEF) were independent of New York Heart Association functional class. Pre-operative end-diastolic diameter proved to be a predictor for pre- and post-operative ΔEF (p = 0.003; p = 0.04) but not for the nature of the exercise response post-operatively. Patients with decreasing and unaltered EF pre-operatively presented a significantly higher but still abnormal ΔEF post-operatively. Those with increasing EF pre-operatively had a similar response and a normal ΔEF post-operatively. Pre-operative ΔEF was not only a predictor for post-operative ΔEF (p = 0.02) but also classified patients into post-operative subgroups (EF decreasing, p = 0.03; unaltered, p = 0.02; increasing, p = 0.0008).

    Conclusions: An abnormal EF response to exercise may also occur in patients who do not fulfill criteria for surgery based on LV dimensions or EF. A follow-up of exercise LV function and adjusting the timing of surgery according to the nature of exercise response could, therefore, be beneficial.

  • 240.
    Tamás, Éva
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet.
    Nielsen, Niels Erik
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet.
    Vanhanen, Ingemar
    Linköpings universitet, Institutionen för medicin och hälsa, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet.
    Nylander, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Measurement of physical work capacity in patients with chronic aortic regurgitation: A potential improvement in patient management2009Inngår i: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 29, nr 6, s. 453-457Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Timing of surgery in aortic regurgitation (AR) is important. Exercise testing is recommended upon uncertainty about functional limitations but reports on cardiopulmonary exercise testing (CPET) in populations with pure chronic AR are scarce. METHOD: Twenty-eight patients referred for surgery because of chronic AR (13 in NYHA I, 10 in NYHA II and five in NYHA III) were tested by CPET pre- and 6 months postoperatively. Echocardiography, with measurement of left ventricular ejection fraction (LVEF), diameters (LVED, LVES) and volumes (LVEDV, LVESV) was also performed. RESULTS: The patients had normal LVEF pre- and postoperatively. LV diameters and volumes diminished significantly postoperatively (LVED from 67 to 57, LVES from 49 to 41 mm; P < 0.001). The majority of the patients had a 'low' physical work capacity, none of them performed better than 'average' according to Astrand's classification preoperatively and there was no significant postoperative improvement. The mean peak oxygen uptake (VO(2peak)) was 25 ml kg(-1) min(-1) both pre- and postoperatively, and six of the 28 patients had a VO(2peak) of less than 20 ml kg(-1) min(-1). VO(2peak) was not significantly related to NYHA class. CONCLUSION: LVEF, diameters and volumes at rest did not fulfil the criteria for surgery in most of our AR patients, of whom 46% were asymptomatic. However, many had a remarkably low work capacity, which was neither improved 6 months postoperatively nor correlated to echocardiographic LV dimensions. CPET predicted the postoperative work capacity and may, therefore, be a useful complement for timing of surgery in patients with chronic AR.

  • 241.
    Tamás, Éva
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Thorax-kärlkliniken.
    Nylander, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Echocardiographic Description of the Anatomic Relations within the Normal Aortic Root2007Inngår i: The Journal of Heart Valve Disease, ISSN 0966-8519, Vol. 16, nr 3, s. 240-246Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background and aim of the study: Diagnostic procedures continue to contain much hidden information that may substantially improve the understanding of the mechanisms of aortic valve disease and its treatment planning. The study aim, using transesophageal echocardiography (TEE), was to describe in detail the anatomical and physiological properties of the normal human aortic root in vivo.

    Methods: The study included 32 patients referred for TEE for suspected cardiac sources of emboli, but diagnosed as normal. Images of the aortic valve in long axis (100-120∞) and short-axis (45-60∞) views were recorded in mid-systole and end-diastole. Parameters of the aortic root (subaortic diameter, sinotubular junction (STJ), maximal sinus diameter, sinus height, cusp diameter, cusp height, opening, coaptation and intercommissural distance) were measured. For repeatability and reliability, two investigators performed the same series of measurements on a subgroup of 11 patients.

    Results: Aortic valve parameters proved to be independent of age, gender, body weight and height, and also of body mass index and body surface area. The subaortic diameter showed no statistically significant connection to maximal sinus diameter or to STJ. No connection was found between STJ and cusp or sinus length in the long-axis view. A simplified regression equation describes the STJ as being three-quarters of the maximal sinus diameter. The valve opening was found to be ca. 80% of the subaortic diameter in systole. Length of coaptation proved to be independent of aortic diameters, but was approximately half of the left coronary (LC) and right coronary (RC) cusp height in diastole. This measurement model proved to be both reliable and reproducible.

    Conclusion: This reliable description of normal anatomic and geometric relations within the aortic root, through extended examination of the aortic root by echocardiography, may facilitate a better planning of aortic valve-preserving interventions.

  • 242.
    Tamás, Éva
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet.
    Nylander, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Olin, Christian
    Linköpings universitet, Institutionen för medicin och hälsa, Thoraxkirurgi. Linköpings universitet, Hälsouniversitetet.
    Are patients with isolated chronic aortic regurgitation operated in time?: Analysis of survival data over a decade2005Inngår i: Clinical Cardiology, ISSN 0160-9289, Vol. 28, nr 7, s. 329-332Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Patients suffering from chronic isolated aortic regurgitation have a less favorable outcome than patients with aortic stenosis. According to international recommendations, these patients should undergo surgery as soon as left ventricular function begins to deteriorate, that is, surgery is not to be postponed until clinical symptoms become relevant.

    Hypothesis: The study was undertaken to evaluate how satisfactory our timing of surgery was, as reflected by survival data.

    Methods: Survival was studied retrospectively in a consecutive series of patients undergoing surgery for chronic isolated aortic regurgitation during a 10-year period in our institution. Results were compared with data from the literature. By excluding patients with aortic aneurysms and acute endocarditis, we formed a homogeneous patient group of 88 subjects.

    Results: Thirty-day mortality was 1% and late mortality after a mean follow-up period of 6 years was 11%. Compared with survival data from an earlier study in which the patient population was similar and resided in the same geographic area, the results in our patient group seem to be better. It is noteworthy that despite a strong effort to recommend surgery at an earlier stage of the disease than previously, 35% of the patients had moderate or severe left ventricular dysfunction pre-operatively because of late referrals.

    Conclusion: This stresses the importance of early detection and careful preoperative follow-up with noninvasive methods in patients with aortic regurgitation.

  • 243. Tanaka, H
    et al.
    Borres, M
    Thulesius, Olav
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi.
    Tamai, H
    Ericson, MO
    Lindblad, LE
    Blood pressure and cardiovascular autonomic function in healthy children and adolescents2000Inngår i: Journal of Pediatrics, ISSN 0022-3476, E-ISSN 1097-6833, Vol. 137, nr 1, s. 63-67Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives: To investigate the relationship between blood pressure levels and cardiovascular autonomic function in adolescents and preadolescents. Study design: We measured variability of beat-to-beat arterial pressure and R-R intervals using power spectral analysis in 56 adolescents (aged 13-16 16 years, mean age, 9.0 +/- 1.4 years) and 71 preadolescents (6-12 years, mean age, 13.5 +/- 1.1 years) in the supine and standing positions. Results: Adolescents had higher levels of systolic arterial pressure and lower high-frequency power of RR intervals than preadolescents. Correlation between the basal level of arterial pressure and autonomic function rn as observed in adolescents but not in preadolescents. Tn adolescents, multivariate analysis indicated that tho basal level of arterial pressure was inversely related with the high-frequency power of RR intervals and positively with the ratio of low-frequency and high-frequency pow er. No significant relation was found in preadolescents. During standing, adolescents had a more marked increase in diastolic arterial pressure, heart rate, low frequency of R-R intervals, and low frequency of arterial pressure compared with those of preadolescents, Changes in diastolic pressure showed a significant negative correlation with changes in high frequency of R-R intervals. Conclusion: Cardiovascular autonomic function plays an important role in increasing blood pressure levels associated with increased modulation of vagal tone of the heart after puberty but does not in the preadolescent.

  • 244.
    Tanaka, H.
    et al.
    Department of Pediatrics, Osaka Medical College, 2-7, Daigakucho, Takatsuki-shi, Osaka 569, Japan.
    Borres, M.
    Department of Pediatrics, Faculty of Medicine, Gothenburg University, Gothenburg, Sweden.
    Thulesius, Olav
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi.
    Tamai, H.
    Department of Pediatrics, Osaka Medical College, 2-7, Daigakucho, Takatsuki-shi, Osaka 569, Japan.
    Ericson, M.O.
    Department of Work Science, Royal Institute of Technology, Stockholm, Sweden.
    Lindblad, L.-E.
    Department of Clinical Physiology, Sodersjukhuset, Stockholm, Sweden.
    Evidence of decreased sympathetic function in children with psychosomatic symptoms2002Inngår i: Clinical Autonomic Research, ISSN 0959-9851, E-ISSN 1619-1560, Vol. 12, nr 6, s. 477-482Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated cardiovascular autonomic function using power spectral analysis of heart rate variation and beat-to-beat finger arterial pressure at rest and while standing and correlated these findings with self-reported psychosomatic and psychosocial symptoms in 122 schoolchildren. Children with three or more psychosomatic and psychosocial symptoms (somatizers) were found to have significantly lower blood pressure than children without symptoms. Somatizers had the more decreased spectral power of the low frequency (LF) band of arterial pressure and RR intervals in the supine position. The high frequency (HF) power did not differ between the two groups. Somatizers showed a more marked reduction in systolic arterial pressure at the onset of standing than did subjects without symptoms but somatizers showed an identical response in systolic arterial pressure when compared to subjects without symptoms during the later stage of standing. The increases in the LF band of arterial pressure and LF/HF of RR intervals during standing were higher in somatizers. These results suggest that somatizers have decreased sympathetic modulation. We conclude that psychosomatic and psychosocial symptoms in children might be associated with low blood pressure and decreased sympathetic modulation.

  • 245.
    Tengblad, Anders
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Allmänmedicin. Linköpings universitet, Hälsouniversitetet.
    Länne, Toste
    Linköpings universitet, Institutionen för medicin och hälsa, Fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Thorax-kärlkliniken.
    Engvall, Jan
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Nyström, Fredrik
    Linköpings universitet, Institutionen för medicin och hälsa, Internmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Endokrin- och magtarmmedicinska kliniken.
    Östgren, Carl Johan
    Linköpings universitet, Institutionen för medicin och hälsa, Allmänmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i västra Östergötland, Primärvården i västra länsdelen.
    Sagittal abdominal diameter and waist circumference as markers of early organ damage in patients with Type 2 diabetes2011Inngår i: Journal of Clinical Metabolism & Diabetes, Vol. 2, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aims: In a cohort of 465 patients with Type 2 diabetes aged 55-66 years the associationbetween the anthropometric measures: Waist circumference (WC) and Sagittal abdominaldiameter (SAD) versus subclinical cardiovascular organ damage by measuring Pulse wavevelocity (PWV) and Left ventricular mass index (LVMI) was studied.

    Methods: Blood pressure, weight, height and WC were measured within primary care. SADwas measured by using standardized calliper equipment. Blood samples were taken foranalysis of HbA1c and serum lipids. LVMI was measured by M-mode echocardiography.Aortic PWV was measured by applanation tonometry (Sphygmocor®) over the carotid andfemoral arteries.

    Results: There were significant correlations between aortic PWV and WC (r=0.23; p<0.01)and SAD (r=0.25; p<0.01). LVMI was also correlated to WC (r=0.26; p<0.01) and SAD(r=0.25; p<0.01). When analysed in a multiple regression model, SAD and WC were bothassociated with PWV and LVMI, independently of age, sex, systolic blood pressure, serumlipids and HbA1c.

    Conclusion: This study shows that abdominal obesity, measured either with WC or SAD, is afeasible risk assessment tool for early subclinical organ damage in patients who have alreadydeveloped Type 2 diabetes.

  • 246.
    Thegerström, Johanna
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk immunologi. Linköpings universitet, Hälsouniversitetet.
    Jönsson, B.
    Department of Infectious Medicine, Institute of Biomedicine, University of Gothenburg, Sweden.
    Brudin, Lars
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Olsen, B.
    Infectious Diseases, Department of Medical Sciences, Uppsala University and Academic Hospital, Uppsala, Sweden.
    Ernerudh, Jan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk immunologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk immunologi och transfusionsmedicin.
    Friman, V.
    Department of Infectious Diseases, Sahlgrenska University Hospital/Östra, University of Gothenburg, Sweden.
    Mycobacterium avium avium and Mycobacterium avium hominissuis give different cytokine responses after in vitro stimulation of human blood mononuclear cells2012Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, nr 4, s. e34391-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Mycobacterium avium is the principal etiologic agent of non-tuberculous lymphadenitis in children. It is also a known pathogen for birds and other animals. Molecular epidemiologic evidence indicates that humans and animals are infected with different M. avium subspecies, namely, M. avium subsp. avium and M. avium subsp. hominissuis, respectively.

    Aim: To investigate the effect on the human immune system of 10 isolates of M. avium subsp. avium mainly isolated from animals and of 11 isolates of M. avium subsp. hominissuis isolated from children with lymphadenitis.

    Method: Peripheral blood mononuclear cells (PBMC) from six healthy blood donors were stimulated in vitro with the inactivated mycobacteria followed by quantification of IL-10, IL-12p70, TNF, IFN-γ and IL-17 in supernatants by multiplex bead array analysis (Luminex).

    Results: M. avium subsp. hominissuis induced significantly more IL-10 and significantly less IL-12p70, TNF, IFN-γ and IL-17 compared to M. avium subsp. avium. All strains induced high levels of IL-17, but very little IL-12.

    Conclusion: The lower T helper (Th) 1 and Th17 responses induced by M. avium subsp. hominissuis compared to M. avium subsp. avium after in vitro stimulation of PBMC might contribute to its higher pathogenicity in humans.

  • 247.
    Thorsson, Ola
    et al.
    Lund University.
    Bjuvang, Agneta
    Malmö University.
    Granerus, Göran
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
    Advantages of standardized criteria for the interpretation of angiotensin-converting enzyme inhibition renography2009Inngår i: NUCLEAR MEDICINE COMMUNICATIONS, ISSN 0143-3636, Vol. 30, nr 6, s. 449-454Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background The aim of this study was to evaluate the efficiency of captopril renography to detect renovascular hypertension (RVH) using the standardized test criteria established at the consensus conference in Santa Fe 1995. The evaluation was made prospectively and in a clinical situation.less thanpgreater thanMethods Renal scintigraphy was performed with Tc-99m-MAG3 according to a 2-day protocol in patients receiving 25 mg captopril 1 h before the test. A baseline study was added only in patients showing abnormal findings in the captopril-stimulated study. All tests were re-evaluated according to the consensus criteria by two nuclear medicine specialists who were unaware of the original evaluation that was made by different doctors on duty at the nuclear medicine section at the time.less than/pgreater than less thanpgreater thanResults Using a 12-month clinical follow-up as a reference, 16 patients in a group of 164 hypertensive patients had RVH, that is, a prevalence of 10%. The re-evaluation and original evaluation indicated a sensitivity of 94 versus 100%, specificity of 97 versus 88%, accuracy of 97 versus 89%, positive predictive value of 83 versus 47%, and negative predictive value of 99 versus 100%. In 15 studies, results from the two evaluations were discordant and in 14 of these studies an originally false positive or intermediate study was re-evaluated as negative. The test result was highly decisive in the future management of patients, minimizing the number of renal angiograms that had to be performed and initiating a search for other causes of secondary hypertension.

    Conclusion Captopril renography is a useful and reliable test in patients with suspicion of RVH. Strict adherence to the diagnostic criteria and recommendations from the 1995 consensus conference further improved the performance of the test compared with clinical follow-up.

  • 248.
    Thulesius, Olav
    Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet.
    Vensystemets fysiologi och patofysiologi2002Inngår i: Klinisk fysiologisk kärldiagnostik / [ed] Tomas Jogestrand, Stefan Rosfors, Lund: Studentlitteratur AB, 2002, s. 245-254Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 249.
    Tisell, Anders
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Dahlqvist Leinhard, Olof
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Warntjes, Jan Bertus Marcel
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Aalto, Arne
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet.
    Smedby, Örjan
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Landtblom, Anne-Marie
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Neurologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Neurologiska kliniken. Östergötlands Läns Landsting, Närsjukvården i västra Östergötland, Medicinska specialistkliniken .
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Increased Concentrations of Glutamate and Glutamine in Normal Appearing White Matter of Patients with Multiple Sclerosis and Normal MR Imaging Brain Scans2013Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, nr 4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In Multiple Sclerosis (MS) the relationship between disease process in normal-appearing white matter (NAWM) and the development of white matter lesions is not well understood. In this study we used single voxel proton ‘Quantitative Magnetic Resonance Spectroscopy’ (qMRS) to characterize the NAWM and thalamus both in atypical ‘Clinically Definite MS’ (CDMS) patients, MRIneg (N = 15) with very few lesions (two or fewer lesions), and in typical CDMS patients, MRIpos (N = 20) with lesions, in comparison with healthy control subjects (N = 20). In addition, the metabolite concentrations were also correlated with extent of brain atrophy measured using Brain Parenchymal Fraction (BPF) and severity of the disease measured using ‘Multiple Sclerosis Severity Score’ (MSSS). Elevated concentrations of glutamate and glutamine (Glx) were observed in both MS groups (MRIneg 8.12 mM, p<0.001 and MRIpos 7.96 mM p<0.001) compared to controls, 6.76 mM. Linear regressions of Glx and total creatine (tCr) with MSSS were 0.16±0.06 mM/MSSS (p = 0.02) for Glx and 0.06±0.03 mM/MSSS (p = 0.04) for tCr, respectively. Moreover, linear regressions of tCr and myo-Inositol (mIns) with BPF were −6.22±1.63 mM/BPF (p<0.001) for tCr and −7.71±2.43 mM/BPF (p = 0.003) for mIns. Furthermore, the MRIpos patients had lower N-acetylaspartate and N-acetylaspartate-glutamate (tNA) and elevated mIns concentrations in NAWM compared to both controls (tNA: p = 0.04 mIns p<0.001) and MRIneg (tNA: p = 0.03 , mIns: p = 0.002). The results suggest that Glx may be an important marker for pathology in non-lesional white matter in MS. Moreover, Glx is related to the severity of MS independent of number of lesions in the patient. In contrast, increased glial density indicated by increased mIns and decreased neuronal density indicated by the decreased tNA, were only observed in NAWM of typical CDMS patients with white matter lesions.

  • 250.
    Tisell, Anders
    et al.
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Medicinsk radiofysik. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Dahlqvist Leinhard, Olof
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US.
    Warntjes, Jan Bertus Marcel
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Lundberg, Peter
    Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för radiologiska vetenskaper. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Centrum för kirurgi, ortopedi och cancervård, Radiofysikavdelningen US. Östergötlands Läns Landsting, Diagnostikcentrum, Röntgenkliniken i Linköping.
    Procedure for Quantitative 1H Magnetic Resonance Spectroscopy and Tissue Characterization of Human Brain Tissue Based on the Use of Quantitative Magnetic Resonance Imaging2013Inngår i: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 70, nr 4, s. 905-915Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    PurposeExisting methods for quantitative magnetic resonance spectroscopy are not widely used for magnetic resonance spectroscopy examinations in clinical practice due to the lengthy and difficult workflow. In this report, we aimed to investigate whether metabolite concentrations show co-variation with relaxation parameters (R-1,R-H2O,R-2,R-H2O), water concentration (C-H2O), and age, using a quantitative magnetic resonance spectroscopy method, which is suitable for a clinical setting. MethodsWe performed 166 single voxel magnetic resonance spectroscopy measurements in the white matter and thalamus in 47 healthy subjects, aged 18-72 years. Whole brain R-1,R-H2O, R-2,R-H2O, and C-H2O maps were determined for each subject using quantitative magnetic resonance imaging. Absolute metabolite concentrations were calculated by calibrating the water-scaled magnetic resonance spectroscopy, using the quantitative magnetic resonance imaging maps of R-1,R-H2O, R-2,R-H2O, and C-H2O. ResultsAbsolute concentrations in white matter of total Creatine and myo-Inositol were correlated with age (total Creatine: 12 4 M/year, P < 0.01; myo-Inositol: 23 +/- 9 M/year, P < 0.05), suggesting a process of increased glia density in aging white matter. Moreover, total Creatine and total N-acetylaspartate were inversely correlated with the R-1,R-H2O and positively correlated with the C-H2O of white matter. In addition, the Cramer-Rao lower bound was biased regarding the metabolite concentration, suggesting that should not be used as a quality assessment. ConclusionThe implemented method was fast, robust, and user-independent.

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