Design evaluation of A-PET: A high sensitivity animal PET camera

Abstract

In recent years it has been shown that PET is capable of obtaining in vivo metabolic images of small animals. These serve as models to study the development and progress of diseases within humans. Imaging small animals requires not only image resolution better than 2 mm, but also high sensitivity in order to image ligands with low specific activity or radiochemical yields. Toward achieving these goals, we have developed a discrete 2 2 10 mm 3 GSO Anger-logic detector for use in a high resolution, high sensitivity, and high count-rate animal PET scanner. This detector uses relatively large 19 mm diameter photomultiplier tubes (PMT), but nevertheless achieves good spatial and energy resolution. The scanner (A-PET) has a port diameter of 21 cm, transverse field-of-view of 12.8 cm, axial length of 11.6 cm, and operates in 3-D volume imaging mode. The absolute coincidence sensitivity is 1.3% for a point source. Due to the use of large PMTs in an Anger design, the encoding ratio (number of crystals/PMT) is high, which reduces the complexity and leads to a cost-effective scanner. Simulation results show that this scanner can achieve high NEC rates for small cylindrical phantoms due to its high sensitivity and low deadtime. Initial measurements show that our design goals for spatial resolution and sensitivity were realized in the prototype scanner.

Modulation of intratumoral hypoxia by the epidermal growth factor receptor inhibitor gefitinib detected using small animal PET imaging

“…The scanner was one of two prototype, preproduction units, the performance characteristics of which have recently been described (12). In brief, the scanner has an effective axial field of view of 11.6 cm and resolution measured at 2.26 mm at the center of the field of view.…”

Embryonic Stem Cell Grafting in Normal and Infarcted Myocardium: Serial Assessment with MR Imaging and PET Dual Detection

“…To monitor the changes of SPIO signal over time, MR imaging was performed in group 1 at day 1 after injection and then weekly for 4 weeks. To compare ventricular function in ESC-treated and culture mediatreated hearts, MR imaging was performed in groups 2 and 3 at day 1, at which time infarct size was also quantified, and at 4 weeks after surgery.PET imaging was performed with a high-resolution (2-mm) dedicated smallanimal PET scanner, which was based on a commercially manufactured unit (Mosaic; Philips Medical Systems, Cleveland, Ohio) (15,16 MR imaging was performed with a 4.7-T horizontal bore magnet (Magnex Scientific, Walnut Creek, Calif) interfaced with a console (Inova; Varian, Palo Alto, Calif). To assess global function and SPIO-associated hypoenhancement, a T2*-weighted fast gradientecho sequence (17) with a 20°flip angle, 3-msec echo time (to minimize cardiac motion), and effective repetition time equal to one heartbeat was * The first time for detection of 1 and 5 million cells is set differently, because on the basis of the pilot study, the earliest time to detect 5 million cells in the heart was day 4 after injection, whereas the earliest time to detect 1 million cells was day 7 after injection (Appendix E1 ͓http://radiology.rsnajnls.org/cgi/content/full/250/3/821/DC1͔).…”

Signal to Noise Ratio of APD-Based Monolithic Scintillator Detectors for High Resolution PET

“…Calculations of the energy resolution of crystal LYSO10-P2 were performed, using separately measured values for the individual contributions in (5). The results of these calculations were compared to measured energy resolutions.…”

“…Calculations according to (5) were also done, again using separately measured values of the individual contributions.…”