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Ekberg, Stefan
Publications (10 of 10) Show all publications
Palhagen, S. E., Ekberg, S., Walinder, J., Granerus, A.-K. & Granerus, G. (2009). HMPAO SPECT in Parkinsons disease (PD) with major depression (MD) before and after antidepressant treatment. JOURNAL OF NEUROLOGY, 256(9), 1510-1518
Open this publication in new window or tab >>HMPAO SPECT in Parkinsons disease (PD) with major depression (MD) before and after antidepressant treatment
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2009 (English)In: JOURNAL OF NEUROLOGY, ISSN 0340-5354, Vol. 256, no 9, p. 1510-1518Article in journal (Refereed) Published
Abstract [en]

Previously we suggested that major depression (MD) in Parkinsons disease (PD) could be an indication of a more advanced and widespread neurodegenerative process, as PD symptoms were more severe in those with depression. We also found a different antidepressant response with SSRI medication in PD patients with depression compared to depressed patients without PD. This indicates diverse underlying pathophysiological mechanisms. Investigations using single-photon emission computed tomography (SPECT), measuring regional cerebral blood flow (rCBF), may contribute to enlighten the neurobiological substrates linked to depressive symptoms. SPECT was performed in order to compare rCBF in MD patients with and without PD. The study included 11 MD patients with PD, 14 nondepressed PD patients and 12 MD patients without PD. All patients were followed for 12 weeks with repeated evaluation of depressive as well as PD symptoms. Anti-Parkinsonian treatment remained unchanged during the study. Antidepressant treatment with SSRI (citalopram) was given to all patients with MD. SPECT was performed before and after 12 weeks of antidepressant treatment. rCBF was found to differ between PD patients with and without MD, as well as between MD patients with and without PD, both at baseline and concerning the response to treatment with SSRI (citalopram). In patients with PD the rCBF was found to be decreased in preoccipital and occipital regions, a finding more common when PD was combined with MD. In summary, larger cortical areas were found to be involved in depressed PD patients, both with hyperactivity (reciprocal to basal degeneration in PD and maybe dopaminergic treatment) and with hypoactivity (probably due to organic lesions leading to hypoperfusion). These observations support our hypothesis that PD combined with MD is an expression of a more advanced and widespread neurodegenerative disorder.

Keywords
rCBF, HMPAO SPECT, Parkinsons disease, Major depression, SSRI
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-20593 (URN)10.1007/s00415-009-5155-x (DOI)
Available from: 2009-09-15 Created: 2009-09-15 Last updated: 2009-09-15
Wallin, A., Ekberg, S., Lind, K., Milos, V., Granérus, A.-K. & Granerus, G. (2007). Posterior cortical brain dysfunction in cognitively impaired patients with Parkinson´s disease - an rCBF scintigraphy study. Acta Neurologica Scandinavica, 116(6), 347-354
Open this publication in new window or tab >>Posterior cortical brain dysfunction in cognitively impaired patients with Parkinson´s disease - an rCBF scintigraphy study
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2007 (English)In: Acta Neurologica Scandinavica, ISSN 0001-6314, E-ISSN 1600-0404, Vol. 116, no 6, p. 347-354Article in journal (Refereed) Published
Abstract [en]

Objectives: The aim of the study was to visualize cortical function in Parkinson's patients with various degrees of cognitive impairment.

Materials and methods: Thirty-seven patients with Parkinson's disease and three with Parkinson plus syndromes underwent cognitive assessment and rCBF using 99mTC-HMPAO-SPECT.

Results: Almost no regional reductions in cerebral blood flow were seen in patients without cognitive impairment (n = 16). Limited, mainly posterior, blood flow reductions were seen in patients with mild cognitive impairment (n = 14), whereas the reductions were extensive and bilaterally symmetric, involving both anterior and posterior brain regions in patients with dementia (n = 10).

Conclusions: The findings suggest a widespread cortical, mainly posterior type of dysfunction and a relationship between the degree of cognitive impairment and the magnitude of the dysfunction.

Keywords
Parkinson's disease, cognitive impairment, SPECT, blood flow, Alzheimer's disease
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-17715 (URN)10.1111/j.1600-0404.2007.00887.x (DOI)
Available from: 2009-04-16 Created: 2009-04-16 Last updated: 2017-12-13
Sparring Björkstén, K., Ekberg, S., Säfström, P., Dige, N. & Granerus, G. (2004). A computerized human reference brain for rCBF/SPET technetium-99m exametazime (HMPAO) investigation of elderly. Clinical Physiology and Functional Imaging, 24(4), 196-204
Open this publication in new window or tab >>A computerized human reference brain for rCBF/SPET technetium-99m exametazime (HMPAO) investigation of elderly
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2004 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 24, no 4, p. 196-204Article in journal (Refereed) Published
Abstract [en]

Using the bull's eye approach, a reference brain from the single photon emission tomography (SPET) images of 10 subjects aged 62-81 years with excellent mental and physical health was constructed. SPET images were acquired twice, 1 week apart, using a single detector rotating gamma camera collecting 64 planar images over a 360° orbit. The centre of each transaxial slice was first defined with an automatic edge detecting algorithm applied to an anterior-posterior and a side profile of the brain. Each slice was divided into 40 sectors. Maximum counts/pixel in each sector was picked. The 40 maximum count values from one transaxial slice were allowed to form a horizontal row in a new parametric image on the x-axis and slice number from the vertex to the basal parts of the brain on the y-axis. This new image was scaled to a 64 × 16 pixel matrix by interpolation, which meant a normalization of all studies to the same size. The parametric image in each subject was scaled with regard to intensity by a factor calculated by a normalization procedure using the least squares analysis. Mean and SD for each pixel were calculated, thereby constructing a 'mean parametric image', and a 'SD parametric image'. These two images are meant to be used as the reference brain for evaluation of patient studies. This method can be used for objective measurements of diffuse brain changes and for pattern recognition in larger groups of patients. Statistical multifactorial analysis of parameters used for acquisition and data processing is possible. © 2004 Blackwell Publishing Ltd.

Keywords
bull's eye, elderly, normal, regional cerebral blood flow, single photon emission tomography, technetium-99m exametazine
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-24634 (URN)6820 (Local ID)6820 (Archive number)6820 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
Borg, R. & Ekberg, S. (2004). Improved dose planning with image fusion. In: European Association of Nuclear Medicine,2004.
Open this publication in new window or tab >>Improved dose planning with image fusion
2004 (English)In: European Association of Nuclear Medicine,2004, 2004Conference paper, Published paper (Other academic)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-28733 (URN)13905 (Local ID)13905 (Archive number)13905 (OAI)
Available from: 2009-10-09 Created: 2009-10-09
Ekberg, S., Olsson, A. & Hellerström, S. (2004). Quality control of gamma cameras with statistical process control. In: European Association of Nuclear Medicine,2004.
Open this publication in new window or tab >>Quality control of gamma cameras with statistical process control
2004 (English)In: European Association of Nuclear Medicine,2004, 2004Conference paper, Published paper (Other academic)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-27437 (URN)12090 (Local ID)12090 (Archive number)12090 (OAI)
Available from: 2009-10-08 Created: 2009-10-08
Fall, P.-A., Ekberg, S., Granerus, A.-K. & Granerus, G. (2000). ECT in Parkinson's disease - dopamine transporter visualised by [I-123]-beta-CIT SPECT. Journal of neural transmission, 107(8-9), 997-1008
Open this publication in new window or tab >>ECT in Parkinson's disease - dopamine transporter visualised by [I-123]-beta-CIT SPECT
2000 (English)In: Journal of neural transmission, ISSN 0300-9564, E-ISSN 1435-1463, Vol. 107, no 8-9, p. 997-1008Article in journal (Refereed) Published
Abstract [en]

Parkinson's disease (PD) is characterised by a loss of dopaminergic neurones in the basal ganglia. These neurones may be visualised by single photon emission computed tomography (SPECT) with the cocaine analogue 2 beta-carboxymethyl-3-beta-(4-iodophenyl)tropane ([(123)]beta-CIT), which labels the dopamine reuptake sites in the nerve terminals. In order to evaluate the possibility to predict the outcome of ECT a prospective study was performed with six PD patients in whom the [I-123]beta-CIT uptake was measured before and after an electroconvulsive therapy (ECT) series. The side-to-side difference in the radiotracer uptake was found to be significantly lower in striatum located contralaterally to the part of the body with the most pronounced symptomathology. No significant change in uptake of the radioligand was seen after ECT. Patients with best uptake and thus with less advanced PD improved most after ECT. The possibility to use the [I-123]beta-CIT uptake to predict the outcome of ECT treatment has to be further evaluated.

Keywords
Parkinson's disease, electroconvulsive therapy, single photon emission computerized tomography (SPECT), [I-123]beta-CIT
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-49623 (URN)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-12
Fall, P.-A., Ekberg, S., Granérus, A.-K. & Granérus, G. (2000). ECT in Parkinson's disease-dopamine transporter visualised by [123I]-beta-CIT SPECT. Journal of Neural Transmission, 107(8-9), 997-1008
Open this publication in new window or tab >>ECT in Parkinson's disease-dopamine transporter visualised by [123I]-beta-CIT SPECT
2000 (English)In: Journal of Neural Transmission, ISSN 0300-9564, Vol. 107, no 8-9, p. 997-1008Article in journal (Refereed) Published
Abstract [en]

Parkinson's disease (PD) is characterised by a loss of dopaminergic neurones in the basal ganglia. These neurones may be visualised by single photon emission computed tomography (SPECT) with the cocaine analogue 2β-carboxymethyl-3-β-(4-iodophenyl)tropane ([123I]β-CIT), which labels the dopamine reuptake sites in the nerve terminals. In order to evaluate the possibility to predict the outcome of ECT a prospective study was per-formed with six PD patients in whom the [123I]β-CIT uptake was measured before and after an electroconvulsive therapy (ECT) series. The side-to-side difference in the radiotracer uptake was found to be significantly lower in striatum located contralaterally to the part of the body with the most pronounced symptomathology. No significant change in uptake of the radioligand was seen after ECT. Patients with best uptake and thus with less advanced PD improved most after ECT. The possibility to use the [123I]β-CIT uptake to predict the outcome of ECT treatment has to be further evaluated.

Keywords
Parkinson's disease, electroconvulsive therapy, single photon emission computerized tomography (SPECT), [123I]β-CIT
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-13533 (URN)10.1007/s007020070048 (DOI)
Available from: 1999-05-28 Created: 1999-05-28 Last updated: 2009-08-18
Malmgren, M., Hellerström, S., Ekberg, S. & Gustafsson, A. (2000). Practical aspects on patient handling in 18F.FDG studies with dual-head coincidence gamma camera.. In: Congress of the European Association of Nuclear Medicine, Paris 2000.,2000: . Paper presented at Congress of the European Association of Nuclear Medicine, 2-6 September 2000, Paris, France.
Open this publication in new window or tab >>Practical aspects on patient handling in 18F.FDG studies with dual-head coincidence gamma camera.
2000 (English)In: Congress of the European Association of Nuclear Medicine, Paris 2000.,2000, 2000Conference paper, Published paper (Refereed)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-27360 (URN)12012 (Local ID)12012 (Archive number)12012 (OAI)
Conference
Congress of the European Association of Nuclear Medicine, 2-6 September 2000, Paris, France
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2015-03-03
Janerot-Sjöberg, B., Ekberg, S., Areskog, M., Nylander, E. & Swahn, E. (1998). Quantitative digital evaluation of myocardial exercise thallium-201 single-photon emission tomography in post-menopausal women. Clinical Physiology, 18(3), 169-177
Open this publication in new window or tab >>Quantitative digital evaluation of myocardial exercise thallium-201 single-photon emission tomography in post-menopausal women
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1998 (English)In: Clinical Physiology, ISSN 0144-5979, E-ISSN 1365-2281, Vol. 18, no 3, p. 169-177Article in journal (Refereed) Published
Abstract [en]

Quantitative computerized analysis of data from myocardial thallium-201 (201Tl) single-photon emission tomography (SPET) may improve the diagnostic accuracy of coronary heart disease. The reference ranges for post-menopausal women are, however, limited and obtained mainly from patients. To compare reference values from healthy post-menopausal women and to improve the quantitative analysis, 20 women (10 patients with coronary heart disease and previous infarction and 10 age-matched healthy volunteers) were examined immediately post exercise and after a delay. A nine-segment 'bull's-eye' model was used for analysis. At visual evaluation, reproducibility was high (93%), no false-positive results were obtained and in 70% of the patients the SPET was interpreted as abnormal. Using reported reference values for quantitative analysis, all the healthy women had an abnormal result. New reference values based on three different methods of 'normalization' were calculated: the relative activity of segment 3 set to 100%, the segment with the highest activity set to 100% and a least-squares method. They all differed significantly from those that had previously been reported. The frequencies of agreement between visual and quantitative analysis were 84-92% and were highest when segment 3 was used as a reference, but in this case only 40% of the patients with coronary heart disease had an abnormal SPET. Using the least-squares method for handling digital information, the SD of the normal values decreased and 90% of the patients with coronary heart disease were accurately diagnosed. These results provide quantitative digital reference values for healthy post-menopausal women. They verify that quantitative analysis is in diagnostic agreement with visual evaluation, stress the need for local verification of reference ranges and suggest a least-square normalization method for the analysis.

National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-67490 (URN)10.1046/j.1365-2281.1998.00090.x (DOI)9649904 (PubMedID)
Available from: 2011-04-14 Created: 2011-04-14 Last updated: 2017-12-11
Alm Carlsson, G., Ekberg, S., Helmrot, E., Lindström, J., Lund, E., Matscheko, G., . . . Stenström, M. (1995). Monte Carlo metoden: ett verktyg inom strålningsfysiken. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Monte Carlo metoden: ett verktyg inom strålningsfysiken
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1995 (Swedish)Report (Other academic)
Abstract [sv]

Detta kompendium är tänkt att användas som ett propedeutiskt kursmaterial för kursdeltagare i kursen "Monte Carlo simulering av foton- och elektrontransport vid diagnostiska och radioterapeutiska strålkvaliteter".

Först följer en kort repetition av den grundläggande statistik som utnyt1jas i beräkningarna. Därefter följer en beskrivning av slumptal. det fundament som metoden bygger på. Vidare beskrivs val ur olika frekvensfunktioner. Valet kan även göras ur så kallade falska fördelningar för att reducera variansen i den skattade storheten. Metoderna belyses i ett avsnitt om problemlösningsmetodik. först i allmänna termer för att sen gå in på ett specifikt problem (Buffons nålproblem) där en analys och strukturering av problemet görs varefter flödesschema och kodning exemplifieras. Så följer två moment där en beskrivning görs av färderna av fotoner respektive elektroner genom materia. För elektronfärderna gör man en indelning i klass 1- och klass II-färder. Vad detta innebär och hur deltapartiklar tas om hand beskrivs i ett kapitel. Till sist kommer en kort introduktion till de tre laborationerna med laborationshandledningar. Speciell vikt har lagts vid att initiera laboranten att fundera på fysiken i de simulerade experimenten.

Detta kompendium har tillkommit som examinationsarbete vid en kurs i "Monte Carlo simulering av foton- och elektrontransport vid diagnostiska och radioterapeutiska strålkvaliteter", med andra ord den kurs du själv nu ämnar studera. Författarna önskar dig lycka till med kursen och hoppas att du kommer att få glädje av den. Speciellt hoppas vi att denna skrift ska underlätta för dig att tillgodogöra dig informationen vid föreläsningarna och under laborationerna.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 1995. p. 87
Series
Report / Department of Radiology, Linköping University, 1990-1997, ISSN 1102-1799 ; 71
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-57752 (URN)LIU-RAD-R-071 (ISRN)
Available from: 2010-06-30 Created: 2010-06-30 Last updated: 2015-03-20Bibliographically approved
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