Performance Evaluation of the GE eXplore Vista Pre-Clinical PET Scanner
Category: Multimodal Imaging - Instrumentation
Yuchuan Wang, Benjamin Tsui, Jurgen Seidel, James Fox, Martin Pomper, Johns Hopkins Medical Institutions, Baltimore, USA. Contact e-mail: mpomper@jhmi.edu
Source: SMI Conference, 2005
Presentation Number: 170
The purpose of the study is to evaluate the performance characteristics of a new GE eXplore Vista pre-clinical PET scanner - a stationary ring-type “depth-of-interaction” system designed for both high sensitivity and high resolution imaging of rodents. The system sensitivity is measured using a line source placed along the central axis of the system. Image resolution is measured across the entire field-of-view (FOV) using a 0.5 mm Na-22 point source. A FORE+FBP and a 3D iterative OS-EM algorithm are used for image reconstructions. Phantom and rodent studies are also performed to evaluate the overall system performance. Our results show that the system sensitivity are 2.1%, 4% and 6.5 % for the 100-700, 250-700 and 400-700 keV energy windows respectively. At the center of central axis, both tangential and radial resolutions are 1.4 mm with FORE+FBP, while the axial resolution is 1.5 mm, yielding a volume resolution of 2.94 mm3. At 1 and 2 cm off-center in radial direction, the resolutions in all three directions are better than 1.7 mm and 2.1 mm, respectively. The 3D OS-EM algorithm, which incorporates accurate system modeling, significantly improves the reconstructed image resolution and a volume resolution of ~1 mm3 is obtained at the center. For the 250-700 keV energy window, the peak NEC rates are 151 kcps at 140 kBq/ml and 197 kcps at 444 kBq/ml, with scatter fractions of 36.7% and 28.4%, for a rat-size and a mouse-size uniform cylindrical phantom, respectively. In the phantom study using a ultra-high resolution phantom, ‘hot’ rods with diameters down to 1.0 mm can be distinguished, especially in images obtained with the 3D OS-EM. In conclusion, the system provides superior performance characteristics as compared to previous generation of pre-clinical PET scanners and is suitable for high resolution and high throughput rodent imaging to evaluate physiology in vivo.
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