VECTor: a preclinical imaging system for simultaneous submillimeter SPECT and PET

J Nucl Med. 2013 Feb;54(2):306-12. doi: 10.2967/jnumed.112.109538. Epub 2012 Oct 17.


Today, PET and SPECT tracers cannot be imaged simultaneously at high resolutions but require 2 separate imaging systems. This paper introduces a Versatile Emission Computed Tomography system (VECTor) for radionuclides that enables simultaneous submillimeter imaging of single-photon and positron-emitting radiolabeled molecules.

Methods: γ-photons produced both by electron-positron annihilation and by single-photon emitters are projected onto the same detectors by means of a novel cylindric high-energy collimator containing 162 narrow pinholes that are grouped in clusters. This collimator is placed in an existing SPECT system (U-SPECT-II) with 3 large-field-of-view γ-detectors. From the acquired projections, PET and SPECT images are obtained using statistical image reconstruction that corrects for energy-dependent system blurring.

Results: For PET tracers, the tomographic resolution obtained with a Jaszczak hot rod phantom was less than 0.8 mm, and 0.5-mm resolution images of SPECT tracers were acquired simultaneously. SPECT images were barely degraded by the simultaneous presence of a PET tracer, even when the activity concentration of the PET tracer exceeded that of the SPECT tracer by up to a factor of 2.5. Furthermore, we simultaneously acquired fully registered 3- and 4-dimensional multiple functional images from living mice that, in the past, could be obtained only sequentially.

Conclusion: High-resolution complementary information about tissue function contained in SPECT and PET tracer distributions can now be obtained simultaneously using a fully integrated imaging device. These combined unique capabilities pave the way for new perspectives in imaging the biologic systems of rodents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calibration
  • Computer Simulation
  • Computers
  • Equipment Design
  • Image Enhancement / methods*
  • Image Processing, Computer-Assisted / methods*
  • Mice
  • Mice, Inbred C57BL
  • Phantoms, Imaging
  • Photons
  • Positron-Emission Tomography / methods*
  • Scattering, Radiation
  • Sensitivity and Specificity
  • Software
  • Tomography, Emission-Computed, Single-Photon / methods*