J Nucl Med. 2008; 49 (Supplement 1):402P
Instrumentation & Data Analysis: InstrumentationInstrumentation Posters |
Performance evaluation of an animal SPECT using modified NEMA standards
K. Lin1,
Ing-Tsung Hsiao1,
C. Wietholt2,
Y. Chung1,
C. Chen2 and
T. Yen1
1 MIC, Chang Gung Memorial Hospital & CGU, Kweishan, Taoyuan, Taiwan;
2 U Chicago, Chicago, Illinois
1692
Objectives: With availability of various preclinical SPECT systems, objective assessment of system performance is needed. To date, no standards for such evaluations have been developed. We modified the clinical NEMA standard NU1-2001 to meet the requirements of preclinical SPECT. We used this modification to independently test our Bioscan NanoSPECT equipped with rat-type collimators having nine 2.5mm pinholes.
Methods: We fabricated lead masks to measure intrinsic spatial resolution (slit opening <1mm), uniformity, and count-rate. We also constructed scaled NEMA phantoms to measure reconstructed spatial resolution, system volume sensitivity, and detector sensitivity variations.
Results: The intrinsic spatial resolution was 3.5mm. The integral and differential uniformity were 45.96% and 38.91%, and 55.07% and 40.69% with mean counts of 16,468 +/- 3045 and 18,404 +/- 1323, for the UFOV and CFOV, respectively. The maximum observed count-rate was 193kcps, and 179.9kcps at 20% loss. The axial and transaxial SPECT reconstructed spatial resolutions without scatter was 1.08mm and 1.11mm, respectively. The reconstructed spatial resolution with scatter was 1.41mm, 1.38mm and 1.39mm for central, radial and tangential line sources. The volume sensitivity per axial centimeter and detector was measured at 9.5kcps/(MBq/cm3) with a maximal detector-to-detector variation of 0.69%.
Conclusions: We designed and applied methods for performance evaluation of preclinical multipinhole SPECT systems based on a modified NEMA standard. The results indicate that the system provides small animal SPECT data with high resolution and sensitivity. Future work will include performance tests of various multipinhole collimators including mouse-type collimators with pinhole diameters of 1.0 and 1.4 mm.
