title: A Promising Future: Comparable Imaging Capability of MRI-Compatible Silicon Photomultiplier and Conventional Photosensor Preclinical PET Systems.
abstract: We recently completed construction of a small-animal PET system-the MiniPET-3-that uses state-of-the-art silicon photomultiplier (SiPM) photosensors, making possible dual-modality imaging with MRI. In this article, we compare the MiniPET-3 with the MiniPET-2, a system with the same crystal geometry but conventional photomultiplier tubes (PMTs).
  
  
  METHODS
  The standard measurements proposed by the National Electrical Manufacturers Association NU 4 protocols were performed on both systems. These measurements included spatial resolution, system sensitivity, energy resolution, counting rate performance, scatter fraction, spillover ratio for air and water, recovery coefficient, and image uniformity. The energy windows were set to 350-650 keV on the MiniPET-2 and 360-662 keV on the MiniPET-3.
  
  
  RESULTS
  Spatial resolution was approximately 17% better on average for the MiniPET-3 than the MiniPET-2. The systems performed similarly in terms of peak absolute sensitivity (∼1.37%), spillover ratio for air (∼0.15), spillover ratio for water (∼0.25), and recovery coefficient (∼0.33, 0.59, 0.81, 0.89, and 0.94). Uniformity was 5.59% for the MiniPET-2 and 6.49% for the MiniPET-3. Minor differences were found in scatter fraction. With the ratlike phantom, the peak noise-equivalent counting rate was 14 kcps on the MiniPET-2 but 24 kcps on the MiniPET-3. However, with the mouselike phantom, these values were 55 and 91 kcps, respectively. The optimal coincidence time window was 6 ns for the MiniPET-2 and 8 ns for the MiniPET-3.
  
  
  CONCLUSIONS
  Images obtained with the SiPM-based MiniPET-3 small-animal PET system are similar in quality to those obtained with the conventional PMT-based MiniPET-2.
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary aron.krizsan@gmail.com.
authors.forename: Aron K
authors.initials: AK
authors.lastname: Krizsan
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Imre
authors.initials: I
authors.lastname: Lajtos
authors.affiliation: Ahmanson Biological Imaging Center, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at University of California, Los Angeles, California.
authors.forename: Magnus
authors.initials: M
authors.lastname: Dahlbom
authors.affiliation: Alfred Mann Institute for Biomedical Engineering, University of Southern California, Los Angeles, California.
authors.forename: Freddie
authors.initials: F
authors.lastname: Daver
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Miklos
authors.initials: M
authors.lastname: Emri
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Sandor A
authors.initials: SA
authors.lastname: Kis
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Gabor
authors.initials: G
authors.lastname: Opposits
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Pohubi
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Norbert
authors.initials: N
authors.lastname: Potari
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Gyula
authors.initials: G
authors.lastname: Hegyesi
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Gabor
authors.initials: G
authors.lastname: Kalinka
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Janos
authors.initials: J
authors.lastname: Gal
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Jozsef
authors.initials: J
authors.lastname: Imrek
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Nagy
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Ivan
authors.initials: I
authors.lastname: Valastyan
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Beata
authors.initials: B
authors.lastname: Kiraly
authors.affiliation: Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen, Hungary; and.
authors.forename: Jozsef
authors.initials: J
authors.lastname: Molnar
authors.affiliation: ST Microelectronics, Catania, Italy.
authors.forename: Delfo
authors.initials: D
authors.lastname: Sanfilippo
authors.affiliation: Department of Nuclear Medicine, Medical Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Balkay
mesh_terms: D000465:Algorithms; D000818:Animals; D005462:Fluorine Radioisotopes; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000639:trends*; D051379:Mice; D064847:Multimodal Imaging / Q000379:methods* / Q000639:trends*; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000295:instrumentation* / Q000639:trends*; D051381:Rats; D015203:Reproducibility of Results; D017948:Retinal Rod Photoreceptor Cells / Q000000981:diagnostic imaging; D012979:Sodium Radioisotopes
chemical_list: D005462:Fluorine Radioisotopes; D012979:Sodium Radioisotopes
keywords: MiniPET; instrumentation; molecular imaging; performance evaluation; small-animal PET scanner