Investigation of the minimum detectable activity level of a preclinical LSO PET scanner

Karakatsanis, N; Bao, Q; Vu, N; Chatziioannou, A

dc.contributor.author	Karakatsanis, N	en
dc.contributor.author	Bao, Q	en
dc.contributor.author	Vu, N	en
dc.contributor.author	Chatziioannou, A	en
dc.date.accessioned	2014-03-01T02:44:45Z
dc.date.available	2014-03-01T02:44:45Z
dc.date.issued	2007	en
dc.identifier.issn	10957863	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/31946
dc.subject	Detection Limit	en
dc.subject	Energy Spectrum	en
dc.subject	filtered backprojection	en
dc.subject	Image Quality	en
dc.subject	Molecular Imaging	en
dc.subject	Point Source	en
dc.subject.other	Concentration (process)	en
dc.subject.other	Crystallography	en
dc.subject.other	Experiments	en
dc.subject.other	Human rehabilitation engineering	en
dc.subject.other	Image quality	en
dc.subject.other	Imaging techniques	en
dc.subject.other	Lutetium	en
dc.subject.other	Plasma diagnostics	en
dc.subject.other	Plastic bottles	en
dc.subject.other	Positron annihilation spectroscopy	en
dc.subject.other	Positron emission tomography	en
dc.subject.other	Scanning	en
dc.subject.other	Scintillation counters	en
dc.subject.other	Solar concentrators	en
dc.subject.other	Spectrum analysis	en
dc.subject.other	Turbulent flow	en
dc.subject.other	Activity concentrations	en
dc.subject.other	Activity distribution	en
dc.subject.other	Detection limit	en
dc.subject.other	En ergy spectrum	en
dc.subject.other	Energy windows	en
dc.subject.other	Filtered backprojection algorithm	en
dc.subject.other	Frame length	en
dc.subject.other	LSO crystals	en
dc.subject.other	MicroPET	en
dc.subject.other	Minimum detectable activity	en
dc.subject.other	Molecular Imaging	en
dc.subject.other	Nuclear sciences	en
dc.subject.other	Operation points	en
dc.subject.other	PET scanners	en
dc.subject.other	Point sources	en
dc.subject.other	Random events	en
dc.subject.other	Signal-to-background ratio	en
dc.subject.other	Simulated data	en
dc.subject.other	Time frames	en
dc.subject.other	Total amount	en
dc.subject.other	Total-energy spectrum	en
dc.subject.other	Medical imaging	en
dc.title	Investigation of the minimum detectable activity level of a preclinical LSO PET scanner	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1109/NSSMIC.2007.4436792	en
heal.identifier.secondary	http://dx.doi.org/10.1109/NSSMIC.2007.4436792	en
heal.identifier.secondary	4436792	en
heal.publicationDate	2007	en
heal.abstract	Novel molecular imaging applications increasingly involve studies where very low amount of activity is present. This operation point can be challenging in terms of image quality especially when the intrinsic detector activity from scintillators such as LSO is considered. LSO crystals contain 176Lu which emits P"" particles followed by y photons, resulting in the detection of true and random events. This background activity has been shown to contribute a significant percentage of the total detected true events, when a very weak activity distribution is imaged. This can affect the weakest signal that can be detected by an LSO PET scanner which determines its ""detection limit"" and is evaluated by the parameter of minimum detectable activity or MDA. A series of acquisitions was performed in order to study the effect of the energy window to the intrinsic true and randoms rate. The experiments were also simulated with GATE, and the results were validated by comparing them with the experiment. Four square regions each with a unique signal to background activity concentration ratio were used. The background activity level was held constant between the different regions, while the activity of the point sources varied in 4 selected levels. The signal to background ratio was calculated separately for each region. The energy spectrum of the intrinsic background activity and its contribution to the total energy spectrum both for singles and coincidences was estimated through the GATE simulation. We histogrammed both the measured and simulated data on various time frames, which we reconstructed using the Filtered Backprojection algorithm. Every image was quantified based on the Currie equation in order to associate an MDA value for each of the 4 point sources as a function of the frame length. In the case of the microPET Focus 220 a total amount of 4nCi/mm3 can be reliably detected for frame lengths longer than 5min and at regions where the signal to background activity concentration ratio is higher than 4. In the case of higher contrast regions detection can be achieved even for frame lengths down to 1min. © 2007 IEEE.	en
heal.journalName	IEEE Nuclear Science Symposium Conference Record	en
dc.identifier.doi	10.1109/NSSMIC.2007.4436792	en
dc.identifier.volume	4	en
dc.identifier.spage	3133	en
dc.identifier.epage	3138	en