title: PET-based geometrical calibration of a pinhole SPECT add-on for an animal PET scanner.
abstract: We developed SPECT imaging capability on an animal PET scanner to provide a cost effective option for animal SPECT imaging. The SPECT add-on sub-system was enabled by mechanically integrating a multiple-pinhole collimator in the PET detector ring. This study introduces a method to calibrate the geometrical parameters of the SPECT add-on using the PET imaging capability of the scanner. The proposed PET imaging-based calibration method consists of two steps: (1) paint the pinhole apertures of the collimator with a positron emitting radioactive solution; and (2) image the collimator inside the scanner in PET mode. The geometrical parameters of the multi-pinhole SPECT add-on can then be derived directly from a set of PET images by simple linear calculation and used in defining the SPECT system. The method was compared to our implementation of a SPECT calibration approach with model-based fitting of SPECT projection data. The procedure for carrying out the PET imaging-based calibration method is simpler and faster than that of our implementation of the SPECT model-based calibration method. Since it does not require model fitting, the uniqueness of the calibration result is warranted. Better quality SPECT images were reconstructed using the PET-derived calibration parameters rather than our implementation of the SPECT model-based calibration parameters. We conclude that the proposed PET imaging-based calibration method provides a highly effective means for enabling SPECT imaging on a PET scanner.
authors: Department of Nuclear Medicine, State University of New York at Buffalo, Buffalo, NY, USA.
authors: Xiao
authors: X
authors: Deng
authors: Jean-François
authors: JF
authors: Beaudoin
authors: Jules
authors: J
authors: Cadorette
authors: Charles
authors: C
authors: Naaman
authors: Roger
authors: R
authors: Lecomte
authors: Rutao
authors: R
authors: Yao
mesh_terms: D000818:Animals; D002138:Calibration; D005260:Female; D051379:Mice; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000295:instrumentation*; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation*