A simulation study for optimizing the injected dose of clinical PET systems

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

dc.contributor.author	Karakatsanis, NA	en
dc.contributor.author	Parasyris, A	en
dc.contributor.author	Nikita, KS	en
dc.contributor.author	Loudos, G	en
dc.date.accessioned	2014-03-01T02:45:04Z
dc.date.available	2014-03-01T02:45:04Z
dc.date.issued	2008	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/32131
dc.subject	Biograph	en
dc.subject	Clinical	en
dc.subject	Dose	en
dc.subject	GATE	en
dc.subject	HR+	en
dc.subject	Monte Carlo	en
dc.subject	NCAT	en
dc.subject	NECR	en
dc.subject	Optimization	en
dc.subject	PET	en
dc.subject	Weight	en
dc.subject.other	Diagnostic radiography	en
dc.subject.other	Digital image storage	en
dc.subject.other	Imaging systems	en
dc.subject.other	Medical imaging	en
dc.subject.other	Mergers and acquisitions	en
dc.subject.other	Monte Carlo methods	en
dc.subject.other	Optimization	en
dc.subject.other	Optoelectronic devices	en
dc.subject.other	Scanning	en
dc.subject.other	Technical presentations	en
dc.subject.other	Tomography	en
dc.subject.other	Windows	en
dc.subject.other	Biograph	en
dc.subject.other	Clinical	en
dc.subject.other	Dose	en
dc.subject.other	GATE	en
dc.subject.other	HR+	en
dc.subject.other	Monte Carlo	en
dc.subject.other	NCAT	en
dc.subject.other	NECR	en
dc.subject.other	PET	en
dc.subject.other	Weight	en
dc.subject.other	Positron emission tomography	en
dc.title	A simulation study for optimizing the injected dose of clinical PET systems	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1109/IST.2008.4659949	en
heal.identifier.secondary	http://dx.doi.org/10.1109/IST.2008.4659949	en
heal.identifier.secondary	4659949	en
heal.publicationDate	2008	en
heal.abstract	The optimization of the injected dose in PET imaging systems is important for the design of clinical data acquisition protocols. Methods to reduce the total amount of radioactive dose injected into a patient are investigated. On the other hand, a lower dose may require a longer data acquisition time to obtain images of high statistical quality, thus limiting the total number of PET scans performed by a PET facility per day. Through dose optimization, a compromise between the total dose injected into a patient and the required scan time can be achieved, by ensuring maximum count rate performance for the scanner. In this study, we use the Noise Equivalent Count Rate (NECR) as a metric of the rate in which statistically important coincidence events are counted by a PET imaging system. The optimal dose is defined as the total amount of dose required to be injected into a patient so as to induce a maximum NECR for the particular scanner and patient. Ideally, it can be estimated by determining a curve of NECR versus the injected dose for each scanner-patient system. Recent studies estimate optimal dose for a particular system by expressing the NECR as a function of the singles rate instead. In this work we propose an alternative method based on a series of simulations of imaging systems and realistic anthropomorphic phantoms. We used Geant4 Application for Tomography Emission (GATE) to simulate a series of scans and study the independent effect of various parameters to the NECR of a clinical PET system. We investigated the relationship between the NECR and the parameters of 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 slow-responding electronics and BGO and finally of the energy window of a system. We used two validated scanner models (ECAT HR+ and Biograph), three NCAT phantoms of different size, two bed positions corresponding to the axial shift of either the heart or the bladder region to the centre of FOV respectively and three energy windows with different low energy thresholds. The results show an optimal mean dose range of 55-65MBq for HR+ and 300-450MBq for Biograph, depending on the patient size, when the heart is located at the centre of axial FOV. ©2008 IEEE.	en
heal.journalName	IST 2008 - IEEE Workshop on Imaging Systems and Techniques Proceedings	en
dc.identifier.doi	10.1109/IST.2008.4659949	en
dc.identifier.spage	98	en
dc.identifier.epage	103	en