PT  - JOURNAL ARTICLE
AU  - Grogg, Kira
AU  - Toole, Terrence
AU  - Ouyang, Jinsong
AU  - Zhu, Xuping
AU  - Normandin, Marc M
AU  - Johnson, Keith
AU  - Alpert, Nathaniel M.
AU  - El Fakhri, Georges
TI  - NEMA and clinical evaluation of a novel brain PET-CT scanner
AID  - 10.2967/jnumed.115.159723
DP  - 2015 Dec 01
TA  - Journal of Nuclear Medicine
PG  - jnumed.115.159723
4099  - http://jnm.snmjournals.org/content/early/2015/12/22/jnumed.115.159723.short
4100  - http://jnm.snmjournals.org/content/early/2015/12/22/jnumed.115.159723.full
AB  - The aim of this study was to determine the performance of a novel mobile human brain/small animal PET-CT system, developed by Photo Diagnostic Systems Inc. The scanner has a 35.7-cm diameter bore and a 22-cm axial extent. The detector ring has 7 modules each with 3×4 cerium-doped lutetium yttrium orthosilicate crystal blocks, each consisting of 22×22 outer layer and 21×21 inner layer crystals, each layer 1 cm thick. Light is collected by 12×12 SiPMs. The integrated CT can be used for attenuation correction and anatomical localization. The scanner was designed as a low-cost device that nevertheless produces high-quality PET images with the unique capability of battery-powered propulsion, enabling use in many settings. Methods: Spatial resolution, sensitivity and noise-equivalent count rate (NECR) were measured based on the National Electrical Manufacturers Association NU2-2012 procedures. Reconstruction was done with tight energy and timing cuts: 400-650 keV and 7ns, and loose cuts: 350-700 keV and 10ns. Additional image quality measurements were made from phantoms, human, and animal studies. Performance was compared to a reference scanner (ECAT Exact HR+) with comparable imaging properties. Results: The full-width half-max transverse resolution at 1 cm (10 cm) radius is 3.2 mm (5.2 mm radial, 3.1 mm tangential) and the axial resolution is 3.5 mm (4.0 mm). For tight (loose) cuts, a sensitivity of 7.5 (11.7) kcps/MBq at the center increases to 8.8 (13.9) kcps/MBq at a 10 cm radial offset. The maximum NECR of 19.5 (22.7) kcps was achieved for an activity concentration of 2.9 kBq/ml. Contrast recovery for 4:1 hot cylinder to warm background was 76% for the 25 mm diameter cylinder, but decreased with decreasing cylinder size. The quantitation agrees within 2% of the known activity distribution and concentration. Brain phantom and human scans have shown agreement in SUV values and image quality with the HR+. Conclusion: We have characterized the performance of the NeuroPET/CT and shown images from the first human studies. The study shows that this scanner achieves good performance when considering spatial resolution, sensitivity, count rate, and image quality along with a low cost and unique mobile capabilities.