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Gustafsson, Agnetha
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Publications (10 of 46) Show all publications
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, p. 231-236Article 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
Keywords
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., Persson, H. L., Schmekel, B., Alm Carlsson, G., Wahlin, K., Sandborg, M. & Gustafsson, A. (2014). Does quantitative lung SPECT detect lung abnormalities earlier than lung function tests?: Results of a pilot study. EJNMMI Research, 4(39), 1-12
Open this publication in new window or tab >>Does quantitative lung SPECT detect lung abnormalities earlier than lung function tests?: Results of a pilot study
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2014 (English)In: EJNMMI Research, ISSN 2191-219X, E-ISSN 2191-219X, Vol. 4, no 39, p. 1-12Article in journal (Refereed) Published
Abstract [en]

Background: Heterogeneous ventilation in lungs of allergic individuals, cigarette smokers, asthmatics and chronic obstructive pulmonary disease (COPD) patients has been demonstrated using imaging modalities such as PET, MR and SPECT. These individuals suffer from narrow and/or closed airways to various extents. By calculating regional heterogeneity in lung ventilation SPECT images as the coefficient of variation (CV) in small elements of the lung, heterogeneity maps and CV-frequency curves can be generated and used to quantitatively measure heterogeneity. This work explores the potential to use such measurements to detect mild ventilation heterogeneities in lung healthy subjects.

Method: Fourteen healthy subjects without documented lung disease or respiratory symptoms, and two patients with documented airway disease, inhaled on average approximately 90 MBq 99mTc-Technegas immediately prior to the 20 min SPECT acquisition. Variation in activity uptake between subjects was compensated for in resulting CV values. The area under the compensated CV frequency curve (AUC), for CV values greater than a threshold value CVT, AUC(CV> CVT), was used as the measure of ventilation heterogeneity.

Results: Patients with lung function abnormalities, according to lung function tests, generated higher AUC(CV>20%) values compared to healthy subjects (p=0.006). Strong linear correlations with the AUC(CV>20%) values were found for age (p=0.006) and height (p=0.001). These demonstrated that ventilation heterogeneities increased with age and that they depend on lung size. Strong linear correlations were found for the lung function value related to indices of airway closure/air trapping, RV/TLC (p=0.009), and DLCOc (p=0.009), a value partly related to supposed ventilation/perfusion mismatch. These findings support the association between conventional lung function tests and the AUC(CV>20%) value.

Conclusions: Among the healthy subjects there is a group with increased AUC(CV>20%) values, but with normal lung function tests, which implies that it might be possible to differentiate ventilation heterogeneities earlier in a disease process than by lung function tests.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2014
Keywords
Quantitative lung SPECT, ventilation heterogeneities, lung function tests
National Category
Clinical Medicine Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-106666 (URN)10.1186/s13550-014-0039-1 (DOI)000358049300001 ()26055938 (PubMedID)2-s2.0-84905881037 (Scopus ID)
Note

On the date of the defence date of the Ph.D. Thesis the status of this article was Manuscript.

Available from: 2014-05-19 Created: 2014-05-19 Last updated: 2017-12-05Bibliographically approved
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
Norberg, P., Persson, H. L., Alm Carlsson, G., Bake, B., Kentson, M., Sandborg, M. & Gustafsson, A. (2013). Quantitative lung SPECT applied on simulated early COPD and humans with advanced COPD. EJNMMI Research, 3(28)
Open this publication in new window or tab >>Quantitative lung SPECT applied on simulated early COPD and humans with advanced COPD
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2013 (English)In: EJNMMI Research, ISSN 2191-219X, E-ISSN 2191-219X, Vol. 3, no 28Article in journal (Refereed) Published
Abstract [en]

BACKGROUND:Reduced ventilation in lung regions affected by chronic obstructive pulmonary disease (COPD), reflected as inhomogeneities in the single-photon emission computed tomography (SPECT) lung image, is correlated to disease advancement. An analysis method for measuring these inhomogeneities is proposed in this work. The first aim was to develop a quantitative analysis method that could discriminate between Monte Carlo simulated normal and COPD lung SPECT images. A second aim was to evaluate the ability of the present method to discriminate between human subjects with advanced COPD and healthy volunteers.

METHODS:In the simulated COPD study, different activity distributions in the lungs were created to mimic the healthy lung (normal) and different levels of COPD. Gamma camera projections were Monte Carlo simulated, representing clinically acquired projections of a patient who had inhaled 125 MBq 99mTc-Technegas followed by a 10-min SPECT examination. Reconstructions were made with iterative ordered subset expectation maximisation. The coefficient of variance (CV) was calculated for small overlapping volumes covering the 3D reconstructed activity distribution. A CV threshold value (CVT) was calculated as the modal value of the CV distribution of the simulated normal. The area under the distribution curve (AUC), for CV values greater than CVT, AUC(CVT), was then calculated. Moreover, five patients with advanced emphysema and five healthy volunteers inhaled approximately 75 MBq 99mTc-Technegas immediately before the 20-min SPECT acquisition. In the human study, CVT was based on the mean CV distribution of the five healthy volunteers.

RESULTS:A significant difference (p < 0.001) was found between the Monte-Carlo simulated normal and COPD lung SPECT examinations. The present method identified a total reduction of ventilation of approximately 5%, not visible to the human eye in the reconstructed image. In humans the same method clearly discriminated between the five healthy volunteers and five patients with advanced COPD (p < 0.05).

CONCLUSIONS:While our results are promising, the potential of the AUC(CVT) method to detect less advanced COPD in patients needs further clinical studies.

Place, publisher, year, edition, pages
Germany: SpringerOpen, 2013
Keywords
Quantitative lung SPECT, Ventilation, Iterative reconstruction, Lung disorder, Monte Carlo, COPD
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-96748 (URN)10.1186/2191-219X-3-28 (DOI)23597059 (PubMedID)
Available from: 2013-08-26 Created: 2013-08-26 Last updated: 2017-12-06
Davidsson, A., Olsson, E., Engvall, J. & Gustafsson, A. (2012). Assessment of image quality for SPECT myocardial perfusion imaging with regard to reconstruction algorithms using visual grading regression.. Paper presented at EANM Milano.
Open this publication in new window or tab >>Assessment of image quality for SPECT myocardial perfusion imaging with regard to reconstruction algorithms using visual grading regression.
2012 (Swedish)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-91091 (URN)
Conference
EANM Milano
Available from: 2013-04-15 Created: 2013-04-15 Last updated: 2013-04-17
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
Norberg, P., Sandborg, M., Alm Carlsson, G., Gustafsson, A., Persson, L., Bake, B. & Kentson, M. (2012). Quantitative lung-SPECT applied on simulated early COPD and humans with advanced COPD. Paper presented at 3:e Nationella mötet om sjukhusfysik, 14-15 november 2012, Djurönäset, Stockholms skärgård.
Open this publication in new window or tab >>Quantitative lung-SPECT applied on simulated early COPD and humans with advanced COPD
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2012 (Swedish)Conference paper, Oral presentation only (Other academic)
Keywords
Quantitative lung-SPECT, ventilation, iterative reconstruction, lung disorder, Monte Carlo, COPD
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-91103 (URN)
Conference
3:e Nationella mötet om sjukhusfysik, 14-15 november 2012, Djurönäset, Stockholms skärgård
Available from: 2013-04-16 Created: 2013-04-16 Last updated: 2015-03-20
Norberg, P., Persson, L., Schmekel, B., Sandborg, M., Kentson, M. & Gustafsson, A. (2012). The potential of quantitative lung SPECT in identifying humans with COPD using the CVT-method: a Pilot Study of advance disease. Paper presented at EANM, Milano, Italy, 27–31 oktober 2012.
Open this publication in new window or tab >>The potential of quantitative lung SPECT in identifying humans with COPD using the CVT-method: a Pilot Study of advance disease
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2012 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-91092 (URN)
Conference
EANM, Milano, Italy, 27–31 oktober 2012
Available from: 2013-04-15 Created: 2013-04-15 Last updated: 2013-09-05
Davidsson, A., Olsson, E., Engvall, J. & Gustafsson, A. (2012). Visuell bedömning av bildkvalitet vid Myokardscintigrafi med avseende på rekonstruktionsalgoritmer. Paper presented at Vårmöte i Nuklearmedicin, Hasseludden.
Open this publication in new window or tab >>Visuell bedömning av bildkvalitet vid Myokardscintigrafi med avseende på rekonstruktionsalgoritmer
2012 (Swedish)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:liu:diva-91090 (URN)
Conference
Vårmöte i Nuklearmedicin, Hasseludden
Available from: 2013-04-15 Created: 2013-04-15 Last updated: 2013-04-17
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