Triple-head gamma camera PET: system overview and performance characteristics

Abstract

Positron emission tomography (PET) is currently performed using either a dedicated PET scanner or scintillation gamma camera equipped with electronic circuitry for coincidence detection of 511 keV annihilation quanta (gamma camera PET system). Although the resolution limits of these two instruments are comparable, the sensitivity and count rate performance of the gamma camera PET system are several times lower than that of the PET scanner. Most gamma camera PET systems are manufactured as dual-detector systems capable of performing dual-head coincidence imaging. One possible step towards the improvement of the sensitivity of the gamma camera PET system is to add another detector head. This work investigates the characteristics of one such triple-head gamma camera PET system capable of performing triple-head coincidence imaging. The following performance characteristics of the system were assessed: spatial resolution, sensitivity, count rate performance. The spatial resolution, expressed as the full width at half-maximum (FWHM), at 1 cm radius is 5.9 mm; at 10 cm radius, the transverse radial resolution is 5.3 mm, whilst the transverse tangential and axial resolutions are 8.9 mm and 13.3 mm, respectively. The sensitivity for a standard cylindrical phantom is 255 counts.s(-1).MBq*(-1)), using a 30% width photopeak energy window. An increase of 35% in the PET sensitivity is achievable by opening an additional 30% width energy window in the Compton region. The count rate in coincidence mode, at the upper limit of the systems optimal performance, is 45 kc.s(-1) (kc=kilocounts) using the photopeak energy window only, and increases to 60 kc.s(-1) using the photopeak + Compton windows. Sensitivity results are compared with published data for a similar dual-head detector system.

PET and SPECT performance of the Siemens HD3 E.Cam/sup duet//spl reg/: a 1" Na(I) hybrid camera

“…In situations when this is possible, the results obtained for this camera compare extremely well to those from other similar systems [2], [5]. It is interesting to notice that although the sensitivity values are relatively low due to the presence of the 3″ thick collimators, the peak NECR exceeds that of other dual-head cameras [2].…”

PET and SPECT performance of the Siemens HD3 e.cam/sup duet//spl reg/ : a 1" Na(I) hybrid camera

“…When this is possible, the results obtained for this camera compare extremely well to those from other similar systems [2,5]. It is interesting to notice that although the sensitivity values are relatively low due to the presence of the 3" thick collimators, the peak NECR exceeds that of other dual head cameras [2].…”

Negative predictive value of F-18-FDG coincidence PET in patients with Hodgkin's disease and a residual mass after therapy: a retrospective diagnostic test study

“…A detailed system description and performance characteristics are given elsewhere. 20,21 About 370 MBq (10 mCi) of 18 F-FDG was administered intravenously to each patient after overnight fasting. Patients received a diuretic to minimize artefacts due to urinary stasis and were kept well hydrated.…”