Statistical parametric maps of 18F-FDG PET and 3-D autoradiography in the rat brain: a cross-validation study

  • Elena Prieto
  • María Collantes
  • Mercedes Delgado
  • Carlos Juri
  • Luis García-García
  • Francisco Molinet
  • María E. Fernández-Valle
  • Miguel A. Pozo
  • Belén Gago
  • Josep M. Martí-Climent
  • José A. Obeso
  • Iván Peñuelas
Original Article



Although specific positron emission tomography (PET) scanners have been developed for small animals, spatial resolution remains one of the most critical technical limitations, particularly in the evaluation of the rodent brain. The purpose of the present study was to examine the reliability of voxel-based statistical analysis (Statistical Parametric Mapping, SPM) applied to 18F-fluorodeoxyglucose (FDG) PET images of the rat brain, acquired on a small animal PET not specifically designed for rodents. The gold standard for the validation of the PET results was the autoradiography of the same animals acquired under the same physiological conditions, reconstructed as a 3-D volume and analysed using SPM.


Eleven rats were studied under two different conditions: conscious or under inhalatory anaesthesia during 18F-FDG uptake. All animals were studied in vivo under both conditions in a dedicated small animal Philips MOSAIC PET scanner and magnetic resonance images were obtained for subsequent spatial processing. Then, rats were randomly assigned to a conscious or anaesthetized group for postmortem autoradiography, and slices from each animal were aligned and stacked to create a 3-D autoradiographic volume. Finally, differences in 18F-FDG uptake between conscious and anaesthetized states were assessed from PET and autoradiography data by SPM analysis and results were compared.


SPM results of PET and 3-D autoradiography are in good agreement and led to the detection of consistent cortical differences between the conscious and anaesthetized groups, particularly in the bilateral somatosensory cortices. However, SPM analysis of 3-D autoradiography also highlighted differences in the thalamus that were not detected with PET.


This study demonstrates that any difference detected with SPM analysis of MOSAIC PET images of rat brain is detected also by the gold standard autoradiographic technique, confirming that this methodology provides reliable results, although partial volume effects might make it difficult to detect slight differences in small regions.


Rat brain Positron emission tomography Three-dimensional autoradiography SPM 


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Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Elena Prieto
    • 1
  • María Collantes
    • 2
  • Mercedes Delgado
    • 3
  • Carlos Juri
    • 4
    • 5
    • 6
    • 7
  • Luis García-García
    • 3
  • Francisco Molinet
    • 2
  • María E. Fernández-Valle
    • 8
  • Miguel A. Pozo
    • 3
  • Belén Gago
    • 4
    • 6
  • Josep M. Martí-Climent
    • 1
  • José A. Obeso
    • 4
    • 5
    • 6
  • Iván Peñuelas
    • 1
    • 2
  1. 1.Nuclear Medicine DepartmentClínica Universidad de NavarraPamplonaSpain
  2. 2.Small Animal Imaging Research UnitCenter for Applied Medical Research (CIMA) and Clínica Universidad de NavarraPamplonaSpain
  3. 3.Brain Mapping UnitUniversidad Complutense de MadridMadridSpain
  4. 4.Movement Disorders Group, Neurosciences DivisionCenter for Applied Medical Research (CIMA)PamplonaSpain
  5. 5.Department of Neurology and NeurosurgeryClínica Universidad de NavarraPamplonaSpain
  6. 6.Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)PamplonaSpain
  7. 7.Department of NeurologyPontificia Universidad Católica de ChileSantiagoChile
  8. 8.MRI Research CenterUniversidad Complutense de MadridMadridSpain

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