Effect of 176Lu intrinsic radioactivity on dual head PET system imaging and data acquisition, simulation, and experimental measurements

dc.contributor.author	Ευθυμίου, Νίκος	el
dc.contributor.author	Λούντος, Γεώργιος	el
dc.contributor.author	Καρακατσάνης, Νικόλαος	el
dc.contributor.author	Παναγιωτάκης, Γιώργος	el
dc.date.accessioned	2015-06-05T17:35:37Z
dc.date.available	2015-06-05T17:35:37Z
dc.date.issued	2015-06-05
dc.identifier.uri	http://hdl.handle.net/11400/15170
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.source	http://scitation.aip.org	en
dc.subject	LSO crystals
dc.subject	Minimum detectable activity
dc.subject	Ελάχιστη ανιχνεύσιμη δραστηριότητα
dc.subject	Κρύσταλλοι LSO
dc.title	Effect of 176Lu intrinsic radioactivity on dual head PET system imaging and data acquisition, simulation, and experimental measurements	en
heal.type	journalArticle
heal.classification	Medicine
heal.classification	Medical physics
heal.classification	Ιατρική
heal.classification	Ιατρική τεχνολογία
heal.classificationURI	http://id.loc.gov/authorities/subjects/sh00006614
heal.classificationURI	http://id.loc.gov/authorities/subjects/sh85083001
heal.classificationURI	N/A-Ιατρική
heal.classificationURI	N/A-Ιατρική τεχνολογία
heal.identifier.secondary	DOI: 10.1118/1.4824694
heal.language	en
heal.access	campus
heal.publicationDate	2013
heal.bibliographicCitation	Efthimiou, N., Loudos, G., Karakatsanis, N., Panayiotakis, G. (2013) Effect of 176Lu intrinsic radioactivity on dual head PET system imaging and data acquisition, simulation, and experimental measurements. "Medical Physics", 40 (11)	en
heal.abstract	In this work, the authors aim for the estimation of the effect of 176Lu intrinsic radioactivity on the performance of a dual head PET system dedicated to small animal imaging. Methods: A prototype camera has been used as a reference system in order to validate two GATE simulation models, which were used for the investigation. The first model includes the 176Lu intrinsic radioactivity, while the second does not. The two models have been designed in order to provide similar sensitivities, in terms of count rate performance and scatter fraction, in the linear range of activities. In addition, the model with the 176Lu intrinsic radioactivity, has been validated in terms of background count rate. Different acquisition schemes have been examined in order to determine the optimum conditions to minimize the 176Lu effects, while maintaining a high trues count rate. In addition, the effect on the image quality, in terms of spatial resolution, signal-to-noise ratio, and minimum detectable activity, was investigated. Results: Both models are in good agreement with the measured data. While, the presence of the 176Lu altered the dead time of the model, it also affected the singles, trues, and randoms count rates. The noise equivalent count rate curves of the two models indicate that for low activities, the lack of 176Lu radioactivity leads to better noise properties due to the underestimation of the randoms. Signal-to-noise ratio measurement on coincidence images confirm the aforementioned claim, since the model without the 176Lu provides better less noisy images. Furthermore, the spatial resolution and the minimum detectable activity are overestimated. Conclusions: It has been proven that the lack of the 176Lu intrinsic radioactivity has an impact on the design of the simulation model's dead time. Even if there is an alignment with experimental results still the noise properties, for a wide range of activities, are overestimated. In addition, for low activities, better image quality, is presented, mainly due to the lack of the 176Lu photons which blur the images. Furthermore, it was shown that the use of a high hardware threshold allows the application of a wide energy window, which improves the statistics without a significant compromise on the quality of the detected photons, mainly, due to the early rejection of the low energy photons and the low scatter factor.	en
heal.journalName	Medical Physics	en
heal.journalType	peer-reviewed
heal.fullTextAvailability	true