PT  - JOURNAL ARTICLE
AU  - Aron Krisztian Krizsan
AU  - Imre Lajtos
AU  - Magnus Dahlbom
AU  - Freddie Daver
AU  - Miklos Emri
AU  - Sandor Attila Kis
AU  - Gabor Opposites
AU  - Laszlo Pohubi
AU  - Delfo Sanfilippo
AU  - Norbert Potari
AU  - Gyula Hegyesi
AU  - Gabor Kalinka
AU  - Janos Gal
AU  - Jozsef Imrek
AU  - Ferenc Nagy
AU  - Ivan Valastyan
AU  - Beata Kiraly
AU  - Jozsef Molnar
AU  - Laszlo Balkay
TI  - Promising future: Comparable Imaging Capability of MRI compatible SiPM and Conventional Photo-sensor Based Preclinical PET Systems
AID  - 10.2967/jnumed.115.157677
DP  - 2015 Oct 01
TA  - Journal of Nuclear Medicine
PG  - jnumed.115.157677
4099  - http://jnm.snmjournals.org/content/early/2015/10/07/jnumed.115.157677.short
4100  - http://jnm.snmjournals.org/content/early/2015/10/07/jnumed.115.157677.full
AB  - The MiniPET-3 presents a preclinical Positron Emission Tomography (PET) scanner that includes state-of-the-art photo sensor technology called Silicon Photomultiplier (SiPM) providing a significant advantage for dual modality purposes with Magnetic Resonance Imaging (MRI). In this article, we propose the image capability comparison based on the National Electrical Manufacturers Association (NEMA) standard NU 4-2008 for two small animal imaging systems with the same crystal geometry but different photo sensors: SiPM for MiniPET-3 and the conventional Photomultiplier Tube (PMT) for MiniPET-2. Methods: The standard measurements proposed by the NEMA NU 4-2008 guideline were performed on both MiniPET systems. These measurements included the determination of spatial resolution, system sensitivity, energy resolution, count rate performance, scatter fraction, spill-over-ratio (SOR) for air and water, recovery coefficients (RC) and image uniformity. For the MiniPET-2 and MiniPET-3 scanners the energy windows of 350-650 keV and 360-662 keV were used respectively. Results: Spatial resolution values were found to be about 17% lower on average for the MiniPET-3 system compared to the MiniPET-2. The two scanners showed similar performance in terms of peak absolute sensitivity (~1.37%) as well as in RC. The SOR air values were 0.14 and 0.27, while the SOR water values were 0.25 and 0.34 for the MiniPET-2 and MiniPET-3 respectively. Uniformity was measured to be 5.59 in the case of MiniPET-2 and 6.49 in case of MiniPET-3. Minor differences were found in scatter fraction. When using a rat phantom, the measured NECR peak on the MiniPET-2 was measured as 14 kcps, while the measured NECR peak on the MiniPET-3 was 24 kcps. However, when using a mouse phantom, the NECR peak on the MiniPET-2 was measured at 55 kcps, while the NECR peak on the MiniPET-3 was measured at 91 kcps. The optimal coincidence time window was found to be 3 ns for the MiniPET-2 and 4 ns for the MiniPET-3. Conclusion: Our results indicate that, the main imaging performance of the SiPM-based MiniPET-3 small animal PET scanner does not significantly differ from that of the conventional PMT photo-detector based MiniPET-2. Based on these preliminary results the MiniPET-3 scanner with MRI compatible photo-sensor (SiPM) produces images of comparable quality for small animal imaging than conventional technology.