Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection

Presence of scattered gamma photons in SPECT projection data degrades the image quality and limits the accuracy in quantification of radiopharmaceutical distribution. Therefore, it is imperative to remove the scattered gamma photons from SPECT data. In this work, a material filter technique, which a...

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Main Authors: Shah, Sayed Inayatullah, Harun, Siti Zawani
Format: Article
Language:English
Published: Springer Netherlands 2011
Subjects:
Online Access:http://irep.iium.edu.my/23912/
http://irep.iium.edu.my/23912/1/Dr_Sayed_KAHS_IREP.pdf
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author Shah, Sayed Inayatullah
Harun, Siti Zawani
author_facet Shah, Sayed Inayatullah
Harun, Siti Zawani
author_sort Shah, Sayed Inayatullah
building IIUM Repository
collection Online Access
description Presence of scattered gamma photons in SPECT projection data degrades the image quality and limits the accuracy in quantification of radiopharmaceutical distribution. Therefore, it is imperative to remove the scattered gamma photons from SPECT data. In this work, a material filter technique, which absorbs some fraction of scattered gamma photons before they can reach the surface of gamma camera detector, was used. A new phantom provides similar cross sectional views of cold and hot regions insert, filled with water and Tc99m radioactivity distributed uniformly in the phantom was scanned. Philip ADAC Forte dual head gamma camera was used with LEHR collimator. Material filter (sheet) - Cu 0.127 mm and Al 0.2 mm thick - was attached (each separately) on the outer surface of the collimator and data were acquired without and with material filter(s). Filtered back projection technique was used with Butterworth filter selecting 0.35 cycles / cm cut-off frequency and order 5. Chang’s method was applied using 0.13/cm  value for attenuation correction. Images were visually inspected in order to observe the cold and hot region detectability. Contrast, SNR and standard deviation in the count density of uniform, cold and hot region images were measured. Results indicate an overall improvement in image uniformity, quality of cold and hot regions and detectability with both material filters in conjunction with Butterworth filter. In conclusion, material filters may improve image quality in clinical studies.
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spelling iium-239122013-01-07T05:00:24Z http://irep.iium.edu.my/23912/ Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection Shah, Sayed Inayatullah Harun, Siti Zawani RC Internal medicine Presence of scattered gamma photons in SPECT projection data degrades the image quality and limits the accuracy in quantification of radiopharmaceutical distribution. Therefore, it is imperative to remove the scattered gamma photons from SPECT data. In this work, a material filter technique, which absorbs some fraction of scattered gamma photons before they can reach the surface of gamma camera detector, was used. A new phantom provides similar cross sectional views of cold and hot regions insert, filled with water and Tc99m radioactivity distributed uniformly in the phantom was scanned. Philip ADAC Forte dual head gamma camera was used with LEHR collimator. Material filter (sheet) - Cu 0.127 mm and Al 0.2 mm thick - was attached (each separately) on the outer surface of the collimator and data were acquired without and with material filter(s). Filtered back projection technique was used with Butterworth filter selecting 0.35 cycles / cm cut-off frequency and order 5. Chang’s method was applied using 0.13/cm  value for attenuation correction. Images were visually inspected in order to observe the cold and hot region detectability. Contrast, SNR and standard deviation in the count density of uniform, cold and hot region images were measured. Results indicate an overall improvement in image uniformity, quality of cold and hot regions and detectability with both material filters in conjunction with Butterworth filter. In conclusion, material filters may improve image quality in clinical studies. Springer Netherlands 2011 Article PeerReviewed application/pdf en http://irep.iium.edu.my/23912/1/Dr_Sayed_KAHS_IREP.pdf Shah, Sayed Inayatullah and Harun, Siti Zawani (2011) Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection. Australasian Physical & Engineering Sciences in Medicine. pp. 1-7. ISSN 0158-9938 (In Press) http://rd.springer.com/journal/13246
spellingShingle RC Internal medicine
Shah, Sayed Inayatullah
Harun, Siti Zawani
Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection
title Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection
title_full Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection
title_fullStr Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection
title_full_unstemmed Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection
title_short Cold and hot region detectability and image quality enhancement in Tc99m SPECT by reduction of scattered gamma photons prior to detection
title_sort cold and hot region detectability and image quality enhancement in tc99m spect by reduction of scattered gamma photons prior to detection
topic RC Internal medicine
url http://irep.iium.edu.my/23912/
http://irep.iium.edu.my/23912/
http://irep.iium.edu.my/23912/1/Dr_Sayed_KAHS_IREP.pdf