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Olsson, Anna
Publications (10 of 14) Show all publications
Brolin, G., Edenbrandt, L., Granerus, G., Olsson, A., Afzelius, D., Gustafsson, A., . . . Ljungberg, M. (2016). The accuracy of quantitative parameters in Tc-99m-MAG3 dynamic renography: a national audit based on virtual image data. Clinical Physiology and Functional Imaging, 36(2), 146-154.
Open this publication in new window or tab >>The accuracy of quantitative parameters in Tc-99m-MAG3 dynamic renography: a national audit based on virtual image data
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2016 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 36, no 2, 146-154 p.Article in journal (Refereed) Published
Abstract [en]

Assessment of image analysis methods and computer software used in Tc-99m-MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in Tc-99m-MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo-simulated scintillation camera imaging of digital phantoms with time-varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines. The differential renal function (DRF) and time to maximum renal activity (T-max) were reported by 21 of the 28 Swedish departments performing Tc-99m-MAG3 studies as of 2012. The reported DRF estimates showed a significantly lower precision for the phantom with impaired renal uptake than for the phantom with normal uptake. The T-max estimates showed a similar trend, but the difference was only significant for the right kidney. There was a significant bias in the measured DRF for all phantoms caused by different positions of the left and right kidney in the anterior-posterior direction. In conclusion, this study shows that virtual scintigraphic studies are applicable for quality assurance and that there is a considerable uncertainty associated with standard quantitative parameters in dynamic Tc-99m-MAG3 renography, especially for patients with impaired renal function.

Place, publisher, year, edition, pages
WILEY-BLACKWELL, 2016
Keyword
Tc-99m-MAG3; differential renal function; digital phantoms; dynamic renography; Monte Carlo imaging simulations; quality assurance
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-125796 (URN)10.1111/cpf.12208 (DOI)000370199700010 ()25348641 (PubMedID)
Note

Funding Agencies|Equalis

Available from: 2016-03-08 Created: 2016-03-04 Last updated: 2017-04-24
Gustafsson, A., Karlsson, H., Nilsson, K. A., Geijer, H. & Olsson, A. (2015). A visual grading study for different administered activity levels in bone scintigraphy. Clinical Physiology and Functional Imaging, 35(3), 231-236.
Open this publication in new window or tab >>A visual grading study for different administered activity levels in bone scintigraphy
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2015 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 35, no 3, 231-236 p.Article in journal (Refereed) Published
Abstract [en]

IntroductionThe aim of the study is to assess the administered activity levels versus visual-based image quality using visual grading regression (VGR) including an assessment of the newly stated image criteria for whole-body bone scintigraphy. Materials and methodsA total of 90 patients was included and grouped in three levels of administered activity: 400, 500 and 600 MBq. Six clinical image criteria regarding image quality was formulated by experienced nuclear medicine physicians. Visual grading was performed in all images, where three physicians rated the fulfilment of the image criteria on a four-step ordinal scale. The results were analysed using VGR. A count analysis was also made where the total number of counts in both views was registered. ResultsThe administered activity of 600 MBq gives significantly better image quality than 400 MBq in five of six criteria (Pless than005). Comparing the administered activity of 600 MBq to 500 MBq, four criteria of six show significantly better image quality (Pless than005). The administered activity of 500 MBq gives no significantly better image quality than 400 Mbq (Pless than005). The count analysis shows that none of the three levels of administrated activity fulfil the recommendations by the EANM. ConclusionThere was a significant improvement in perceived image quality using an activity level of 600 MBq compared to lower activity levels in whole-body bone scintigraphy for the gamma camera equipment end set-up used in this study. This type of visual-based grading study seems to be a valuable tool and easy to implement in the clinical environment.

Place, publisher, year, edition, pages
Wiley: 12 months, 2015
Keyword
bone and bones; evaluation; radionuclide imaging; technetium Tc 99 m
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-117784 (URN)10.1111/cpf.12155 (DOI)000352726400010 ()24797289 (PubMedID)
Note

Funding Agencies|County Council of Ostergotland, Sweden

Available from: 2015-05-11 Created: 2015-05-08 Last updated: 2017-12-04
Norberg, P., Olsson, A., Alm Carlsson, G., Sandborg, M. & Gustafsson, A. (2015). Optimisation of quantitative lung SPECT applied to mild COPD: a software phantom simulation study. EJNMMI research, 5(16).
Open this publication in new window or tab >>Optimisation of quantitative lung SPECT applied to mild COPD: a software phantom simulation study
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2015 (English)In: EJNMMI research, ISSN 2191-219X, Vol. 5, no 16Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: The amount of inhomogeneities in a (99m)Tc Technegas single-photon emission computed tomography (SPECT) lung image, caused by reduced ventilation in lung regions affected by chronic obstructive pulmonary disease (COPD), is correlated to disease advancement. A quantitative analysis method, the CVT method, measuring these inhomogeneities was proposed in earlier work. To detect mild COPD, which is a difficult task, optimised parameter values are needed.

METHODS: In this work, the CVT method was optimised with respect to the parameter values of acquisition, reconstruction and analysis. The ordered subset expectation maximisation (OSEM) algorithm was used for reconstructing the lung SPECT images. As a first step towards clinical application of the CVT method in detecting mild COPD, this study was based on simulated SPECT images of an advanced anthropomorphic lung software phantom including respiratory and cardiac motion, where the mild COPD lung had an overall ventilation reduction of 5%.

RESULTS: The best separation between healthy and mild COPD lung images as determined using the CVT measure of ventilation inhomogeneity and 125 MBq (99m)Tc was obtained using a low-energy high-resolution collimator (LEHR) and a power 6 Butterworth post-filter with a cutoff frequency of 0.6 to 0.7 cm(-1). Sixty-four reconstruction updates and a small kernel size should be used when the whole lung is analysed, and for the reduced lung a greater number of updates and a larger kernel size are needed.

CONCLUSIONS: A LEHR collimator and 125 (99m)Tc MBq together with an optimal combination of cutoff frequency, number of updates and kernel size, gave the best result. Suboptimal selections of either cutoff frequency, number of updates and kernel size will reduce the imaging system's ability to detect mild COPD in the lung phantom.

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-117857 (URN)10.1186/s13550-015-0086-2 (DOI)000358130300001 ()25853022 (PubMedID)
Available from: 2015-05-12 Created: 2015-05-12 Last updated: 2016-04-24
Norberg, P., Olsson, A., Alm Carlsson, G., Sandborg, M. & Gustafsson, A. (2014). Optimisation of quantitative lung SPECT applied to mild COPD: a Monte Carlo-based analysis. .
Open this publication in new window or tab >>Optimisation of quantitative lung SPECT applied to mild COPD: a Monte Carlo-based analysis
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2014 (English)Manuscript (preprint) (Other academic)
Abstract [en]

The amount of inhomogeneities in a single photon emission computed tomography (SPECT) lung image, caused by reduced ventilation in lung regions affected by chronic obstructive pulmonary disease (COPD), is correlated to disease advancement. A quantitative analysis method, the CVT-method, measuring these inhomogeneities was proposed in earlier work (Norberg et al., 2013). To detect mild COPD, which is a difficult task, optimized parameter values are needed. In this work, the CVT-method was optimized with respect to the parameter values of acquisition, reconstruction and analysis. The ordered subset expectation maximization (OSEM) algorithm was used for reconstructing the lung SPECT images. As a first step towards clinical application of the CVT-method in detecting mild COPD, this study was based on simulated SPECT images of an advanced anthropomorphic lung phantom including respiratory and cardiac motion, where the mild COPD lung had an overall ventilation reduction of 5%. The largest separation between healthy and mild COPD lung images as determined using the CVT-measure of ventilation inhomogeneity and 125 MBq 99mTc was obtained using a low-energy high-resolution collimator and a Butterworth postfilter with a cut-off frequency of 0.6-0.7 cm-1. Sixty-four reconstruction updates should be used when the whole lung is analysed and for the reduced lung a greater number of updates is needed.

National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-106665 (URN)
Available from: 2014-05-19 Created: 2014-05-19 Last updated: 2015-03-31Bibliographically approved
Brolin, G., Granerus, G., Olsson, A., Edenbrandt, L. & Ljungberg, M. (2012). A new Method for Monte Carlo Simulations of Dynamic Scintillation Camera Imaging: 99mTc MAG3 Renography Studies. In: : . Paper presented at EANM'12 Annual Congress of the European Association of Nuclear Medicine, October 27 - 31, 2012, Milan, Italy. .
Open this publication in new window or tab >>A new Method for Monte Carlo Simulations of Dynamic Scintillation Camera Imaging: 99mTc MAG3 Renography Studies
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2012 (English)Conference paper, Oral presentation with published abstract (Other academic)
National Category
Radiology, Nuclear Medicine and Medical Imaging Other Physics Topics
Identifiers
urn:nbn:se:liu:diva-90883 (URN)
Conference
EANM'12 Annual Congress of the European Association of Nuclear Medicine, October 27 - 31, 2012, Milan, Italy
Available from: 2013-04-08 Created: 2013-04-08 Last updated: 2014-06-17
Kvernby, S., Olsson, A. & Gustafsson, A. (2012). Opimization of activity level in rCBF SPECT using observer study Visual Grading Regression. Paper presented at Nationellt möte om Sjukhusfysik, Djurönäset 14-15 november 2012. .
Open this publication in new window or tab >>Opimization of activity level in rCBF SPECT using observer study Visual Grading Regression
2012 (English)Conference paper, Oral presentation with published abstract (Other academic)
National Category
Other Physics Topics
Identifiers
urn:nbn:se:liu:diva-90887 (URN)
Conference
Nationellt möte om Sjukhusfysik, Djurönäset 14-15 november 2012
Available from: 2013-04-08 Created: 2013-04-08 Last updated: 2013-04-19
Olsson, A., Sundström, T., Larsson, A., Sandborg, M. & Gustafsson, A. (2010). A strategy for optimisation of nuclear medicine examinations – application to rCBF SPECT. Paper presented at World Federation Congress in Nuclear Medicine and Biology, WFNMB 2010, 18-23 September, Cape Town. .
Open this publication in new window or tab >>A strategy for optimisation of nuclear medicine examinations – application to rCBF SPECT
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2010 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Medical Image Processing
Identifiers
urn:nbn:se:liu:diva-79377 (URN)
Conference
World Federation Congress in Nuclear Medicine and Biology, WFNMB 2010, 18-23 September, Cape Town
Available from: 2012-07-16 Created: 2012-07-16 Last updated: 2013-09-03
Olsson, A., Nilsson, K. A., Lindblom, G., Karlsson, H. & Gustafsson, A. (2010). Bedömning av bildkvalitet med hjälp av VGC på helkroppsscanning vid skelettscintigrafi. Paper presented at Svenskt Vårmöte i Nuklearmedicin, Göteborg. .
Open this publication in new window or tab >>Bedömning av bildkvalitet med hjälp av VGC på helkroppsscanning vid skelettscintigrafi
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2010 (Swedish)Conference paper, Oral presentation only (Other academic)
National Category
Medical Image Processing
Identifiers
urn:nbn:se:liu:diva-79382 (URN)
Conference
Svenskt Vårmöte i Nuklearmedicin, Göteborg
Available from: 2012-07-16 Created: 2012-07-16 Last updated: 2012-08-14
Olsson, A., Ärlig, Å., Alm Carlsson, G. & Gustafsson, A. (2007). Evaluation of reconstruction techniques in regional cerebral blood flow SPECT using trade-off plots: A Monte Carlo study. Nuclear medicine communications, 28(9), 719-725.
Open this publication in new window or tab >>Evaluation of reconstruction techniques in regional cerebral blood flow SPECT using trade-off plots: A Monte Carlo study
2007 (English)In: Nuclear medicine communications, ISSN 0143-3636, E-ISSN 1473-5628, Vol. 28, no 9, 719-725 p.Article in journal (Refereed) Published
Abstract [en]

BACKGROUND AND AIM: The image quality of single photon emission computed tomography (SPECT) depends on the reconstruction algorithm used. The purpose of the present study was to evaluate parameters in ordered subset expectation maximization (OSEM) and to compare systematically with filtered back-projection (FBP) for reconstruction of regional cerebral blood flow (rCBF) SPECT, incorporating attenuation and scatter correction. METHODS: The evaluation was based on the trade-off between contrast recovery and statistical noise using different sizes of subsets, number of iterations and filter parameters. Monte Carlo simulated SPECT studies of a digital human brain phantom were used. The contrast recovery was calculated as measured contrast divided by true contrast. Statistical noise in the reconstructed images was calculated as the coefficient of variation in pixel values. RESULTS: A constant contrast level was reached above 195 equivalent maximum likelihood expectation maximization iterations. The choice of subset size was not crucial as long as there were > or = 2 projections per subset. The OSEM reconstruction was found to give 5-14% higher contrast recovery than FBP for all clinically relevant noise levels in rCBF SPECT. The Butterworth filter, power 6, achieved the highest stable contrast recovery level at all clinically relevant noise levels. The cut-off frequency should be chosen according to the noise level accepted in the image. CONCLUSION: Trade-off plots are shown to be a practical way of deciding the number of iterations and subset size for the OSEM reconstruction and can be used for other examination types in nuclear medicine.

Place, publisher, year, edition, pages
United States: Lippincott Williams & Wilkins, 2007
Keyword
rCBF, SPECT (tomography, emission-computed, single-photon), image reconstruction (image processing, computer-assisted), Monte Carlo (Monte Carlo method)
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-21149 (URN)10.1097/MNM.0b013e328274204d (DOI)17667751 (PubMedID)
Available from: 2009-09-29 Created: 2009-09-29 Last updated: 2017-12-13
Milakovic, M., Berg, G., Eggertsen, R., Nyström, E., Olsson, A., Larsson, A. & Hansson, M. (2006). Determination of intrathyroidal iodine by X-ray fluorescence analysis in 60- to 65-year olds living in an iodine-sufficient area. Journal of Internal Medicine, 260(1), 69-75.
Open this publication in new window or tab >>Determination of intrathyroidal iodine by X-ray fluorescence analysis in 60- to 65-year olds living in an iodine-sufficient area
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2006 (English)In: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 260, no 1, 69-75 p.Article in journal (Refereed) Published
Abstract [en]

Objectives. X-ray fluorescence (XRF) is a non-invasive method for determining the iodine content of the thyroid gland in vivo. In spite of the obvious clinical value of such a method in situations of iodine deficiency or iodine overload, the method has not so far been widely used. The objective was to investigate the applicability of the XRF method in a larger number of subjects. Design and subjects. The study comprised 37 individuals, aged 60-65 years, who had spent their entire life with iodine supplementation through iodinated table salt. Individuals with (previous) thyroid disease were excluded. The individual thyroid function had previously been evaluated by measurements of thyroid-related hormones, thyroid volume and 131-Iodine (131I) uptake which indicated a sufficient iodine intake of the population in the area. Iodine in the right thyroid lobe in each subject was examined using XRF. Results. The mean thyroid iodine concentration was 0.4 mg mL-1, corresponding to a mean total iodine content of 5.2 mg (range 0.9-20.2). There was a pronounced difference between individuals. No correlation was found between iodine concentration and 131I uptake or thyroid volume. Neither was iodine content and 131I uptake correlated. Conclusions. In a population living under iodine-sufficient conditions, a large variation of iodine stored in the thyroid is compatible with euthyroidism. Determination of the iodine pool by XRF investigation is feasible in a clinical setting and the method offers a unique possibility to study the intrathyroidal iodine pool in subjects with thyroid disease. The low radiation dose enables the use of the method in pregnant women and also in young individuals. © 2006 Blackwell Publishing Ltd.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-36828 (URN)10.1111/j.1365-2796.2006.01660.x (DOI)32704 (Local ID)32704 (Archive number)32704 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
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