title: Performance characterization of the Inveon preclinical small-animal PET/SPECT/CT system for multimodality imaging.
abstract: OBJECTIVE
  We investigated the performance of the Inveon small-animal PET/SPECT/CT system and compared the imaging capabilities of the SPECT and PET components.
  
  
  METHODS
  For SPECT, the energy resolution, tomographic spatial resolution and system sensitivity were evaluated with a (99m)Tc solution using a single pinhole collimator. For PET, the spatial resolution, absolute sensitivity, scatter fraction and peak noise equivalent count were evaluated. Phantoms and a normal rat were scanned to compare the imaging capabilities of SPECT and PET.
  
  
  RESULTS
  The SPECT spatial resolution was 0.84 mm full-width at half-maximum (FWHM) at a radius of rotation of 25 mm using a 0.5-mm pinhole aperture collimator, while the PET spatial resolution was 1.63 mm FWHM at the centre. The SPECT system sensitivity at a radius of rotation of 25 mm was 35.3 cps/MBq (4 × 10(-3)%) using the 0.5-mm pinhole aperture, while the PET absolute sensitivity was 3.2% for 350-650 keV and 3.432 ns. Accordingly, the volume sensitivity of PET was three orders of magnitude higher than that of SPECT.
  
  
  CONCLUSIONS
  This integrated PET/SPECT/CT system showed high performance with excellent spatial resolution for SPECT and sensitivity for PET. Based on the tracer availability and system performance, SPECT and PET have complementary roles in multimodality small-animal imaging.
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan. magota@huhp.hokudai.ac.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Magota
authors.forename: Naoki
authors.initials: N
authors.lastname: Kubo
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kuge
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Nishijima
authors.forename: Songji
authors.initials: S
authors.lastname: Zhao
authors.forename: Nagara
authors.initials: N
authors.lastname: Tamaki
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods