A simulation study of the counting-rate performance of clinical PET systems applying a methodology for optimizing the injected dose

Karakatsanis, NA; Parasyris, A; Loudos, G; Nikita, KS

dc.contributor.author	Karakatsanis, NA	en
dc.contributor.author	Parasyris, A	en
dc.contributor.author	Loudos, G	en
dc.contributor.author	Nikita, KS	en
dc.date.accessioned	2014-03-01T02:45:04Z
dc.date.available	2014-03-01T02:45:04Z
dc.date.issued	2008	en
dc.identifier.issn	10957863	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/32132
dc.subject	Clinical Study	en
dc.subject	Data Acquisition	en
dc.subject	Imaging System	en
dc.subject	Simulation Study	en
dc.subject	Field of View	en
dc.subject	Injected Dose	en
dc.subject	Noise Equivalent Count	en
dc.subject.other	Acquisition time	en
dc.subject.other	Activity levels	en
dc.subject.other	Alternative methods	en
dc.subject.other	Axial positions	en
dc.subject.other	Clinical study	en
dc.subject.other	Data acquisition protocol	en
dc.subject.other	Deadtime	en
dc.subject.other	Energy windows	en
dc.subject.other	Field of views	en
dc.subject.other	Human phantoms	en
dc.subject.other	LSO crystals	en
dc.subject.other	Noise equivalent count rates	en
dc.subject.other	Optimal ranges	en
dc.subject.other	Patient size	en
dc.subject.other	Peak values	en
dc.subject.other	Performance parameters	en
dc.subject.other	PET Scan	en
dc.subject.other	Projection data	en
dc.subject.other	Rate performance	en
dc.subject.other	Simulation studies	en
dc.subject.other	Statistical quality	en
dc.subject.other	Optimization	en
dc.subject.other	Optoelectronic devices	en
dc.subject.other	Positron emission tomography	en
dc.subject.other	Windows	en
dc.subject.other	Scanning	en
dc.title	A simulation study of the counting-rate performance of clinical PET systems applying a methodology for optimizing the injected dose	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1109/NSSMIC.2008.4774367	en
heal.identifier.secondary	http://dx.doi.org/10.1109/NSSMIC.2008.4774367	en
heal.identifier.secondary	4774367	en
heal.publicationDate	2008	en
heal.abstract	The amount of radioactivity injected into patients during clinical PET scans can be critical when designing data acquisition protocols. The objective is to generate projection data with high statistical quality, while the acquisition time remains relatively short and the total amount of injected activity does not exceed a certain level, above which the count losses, due to deadtime effects, become significant. For this purpose an optimal range of total injected activity levels can be determined by employing the performance parameter of the Noise Equivalent Count Rate (NECR). NECR is defined as a metric of the rate in which statistically important coincidence events are counted by a PET system. The NECR depends on the total amount of injected activity and demonstrates a peak value for a certain range of activity levels. However this dependence can be affected by certain patient- and scanner-related parameters causing the shift of the range. Therefore the optimal range can be determined by estimating the NECR response as a function of the activity for a particular scanner-patient system. This is not practical for clinical studies, as it would require the repetition of the method for each patient. In this work we propose an alternative method based on a series of simulations of imaging systems and realistic human phantoms. We used Geant4 Application for Tomography Emission to simulate the independent effect of certain parameters to the NECR. We investigated the relationship between the NECR and the patient size, relative axial position of the patient to the field of view (FOV) of the scanner, combined use of reduced dead time electronics and LSO crystals instead of slowresponding electronics and BGO and finally of the energy window. We used two validated scanner models, three NCAT phantoms, two bed positions and three energy windows. The results show an optimal range of 55-65MBq for HR+ and 300450MBq for Biograph, when the heart is located at the centre of FOV. ©2008 IEEE.	en
heal.journalName	IEEE Nuclear Science Symposium Conference Record	en
dc.identifier.doi	10.1109/NSSMIC.2008.4774367	en
dc.identifier.spage	5014	en
dc.identifier.epage	5019	en