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Pitfalls in Doppler evaluation of diastolic function: insights from three-dimensional magnetic resonance imaging
Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences.
Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences.
Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences.
Linköping University, Department of Medicine and Health Sciences, Clinical Physiology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.ORCID iD: 0000-0003-1395-8296
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1999 (English)In: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 12, no 10, 817-826 p.Article in journal (Refereed) Published
Abstract [en]

Ultrasound-Doppler assessment of diastolic function is subject to velocity errors caused by angle sensitivity and a fixed location of the sample volume. We used 3-dimensional phase contrast magnetic resonance imaging (MRI) to evaluate these errors in 10 patients with hypertension and in 10 healthy volunteers. The single (Doppler) and triple (MRI) component velocity was measured at early (E) and late (A) inflow along Doppler-like sample lines or 3-dimensional particle traces generated from the MRI data. Doppler measurements underestimated MRI velocities by 9.4% ± 8.6%; the effect on the E/A ratio was larger and more variable. Measuring early and late diastolic inflows from a single line demonstrated the error caused by their 3-dimensional spatial offset. Both errors were minimized by calculating the E/A ratio from maximal E and A values without constraint to a single line. Alignment and spatial offset are important sources of error in Doppler diastolic parameters. Improved accuracy may be achieved with the use of maximal E and A velocities from wherever they occur in the left ventricle.

Place, publisher, year, edition, pages
Amsterdam: Elsevier Science B.V. , 1999. Vol. 12, no 10, 817-826 p.
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-14555DOI: 10.1016/S0894-7317(99)70186-0ISI: 83255200007PubMedID: 10511650OAI: oai:DiVA.org:liu-14555DiVA: diva2:23717
Available from: 2007-06-04 Created: 2007-06-04 Last updated: 2016-03-14
In thesis
1. Dynamiskt lärande: En ämnesdidaktisk avhandling om fysiologiska fenomen och läkarstudentens lärande
Open this publication in new window or tab >>Dynamiskt lärande: En ämnesdidaktisk avhandling om fysiologiska fenomen och läkarstudentens lärande
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

It is well known that the outcome of teaching and learning in higher education is often unsatisfactory. Earlier studies have shown that medical students often have a surface approach to their studies and that misconceptions of fundamental physiological phenomena are common. The aim of this thesis is to support educational practice in medicine, particularly in medical physiology. The thesis can be categorised as subject matter-specific education research, which means that questions about teaching and learning are closely linked to the subject studied. The researcher should be well acquainted with the subject in question. The subject area dealt with in this thesis is physiological phenomena related to cardiovascular pressure-flow relations.

The thesis consists of studies of 3-dimensional intra cardiac pressure-flow phenomena in the heart (studies 1 and 2) and studies of how students conceive of and develop an understanding of physiological phenomena related to blood pressure and blood pressure regulation (studies 3 and 4).

Flow in the left atrium as well as inflow-patterns to the left ventricle were studied. The 3-dimensional method elucidates vortical flow phenomena which were previously unknown. The findings could contribute to increasing physicians and technicians understanding of flow phenomena in the diagnosis and assessment of heart disease and to the further development of diagnostic methods. In the studies of learning and understanding of physiological phenomena, the findings point to new aspects of a deep approach to learning, which have to do with the students’ ability to change perspective and adopt a variety of learning strategies to a phenomenon (Moving) versus a tendency to hold on to one explanatory model (Holding). The study also investigates the students’ ability to identify and apply fundamental physiological principles as well as how they conceive of the importance of detailed knowledge for understanding of physiology. The findings point to differences in the students’ conceptions of physiological principles. A problemising approach, which includes not only causally described relations, indicates a more complex conception of physiological phenomena. The study shows aspects of understanding which are seldom assessed in examinations.

The findings indicate a connection between the students’ approaches to learning and the quality of their understanding of fundamental physiological principles. In the thesis, teaching interventions are proposed in order to stimulate dynamic learning and a learning environment where students are not afraid to challenge their conceptions in order to acquire a rich and nuanced picture of physiological phenomena.

Place, publisher, year, edition, pages
Institutionen för medicin och vård, 2007
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 976
Keyword
Lärande, Förståelse, Fysiologi
National Category
Physiology
Identifiers
urn:nbn:se:liu:diva-9026 (URN)91-85643-34-3 (ISBN)
Public defence
2007-01-18, Berzeliussalen, Campus US, Universitetssjukhuset, Lihköping, 13:00 (English)
Opponent
Supervisors
Available from: 2007-06-04 Created: 2007-06-04 Last updated: 2009-08-22

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Fyrenius, AnnaWigström, LarsBolger, Ann F.Ebbers, TinoKarlsson, MattsWranne, BengtEngvall, Jan

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Fyrenius, AnnaWigström, LarsBolger, Ann F.Ebbers, TinoKarlsson, MattsWranne, BengtEngvall, Jan
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Clinical Physiology Faculty of Health SciencesDepartment of Clinical PhysiologyInternal MedicineBiomedical Modelling and SimulationThe Institute of Technology
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Journal of the American Society of Echocardiography
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