Rodent brain imaging with SPECT/CT

Med Phys. 2007 Apr;34(4):1217-20. doi: 10.1118/1.2710950.

Abstract

We evaluated methods of imaging rat models of stroke in vivo using a single photon emission computed tomography (SPECT) system dedicated to small animal imaging (X-SPECT, Gamma Medica-Ideas, Northridge, CA). An animal model of ischemic stroke was developed for in vivo SPECT/CT imaging using the middle cerebral artery occlusion (MCAO) technique. The presence of cerebral ischemia was verified in ex vivo studies using triphenyltetrazolium chloride (TTC) staining. In vivo radionuclide imaging of cerebral blood flow was performed in rats following MCAO using dynamic planar imaging of 99mTc-exametazime with parallel hole collimation. This was followed immediately by in vivo radionuclide imaging of cerebral blood flow with 99mTc-exametazime in the same animals using 1-mm pinhole SPECT. Correlated computed tomography imaging was performed to localize radiopharmaceutical uptake. The animals were allowed to recover and ex vivo autoradiography was performed with separate administration of 99mTc-exametazime. Time activity curve of 99mTc-exametazime showed that the radiopharmaceutical uptake could be maintained for over 9 min. The activity would be expected to be relatively stable for a much longer period, although the data were only obtained for 9 min. TTC staining revealed sizable infarcts by visual observation of inexistence of TTC stain in infracted tissues of MCAO rat brains. In vivo SPECT imaging showed cerebral blood flow deficit in the MCAO model, and the in vivo imaging result was confirmed with ex vivo autoradiography. We have demonstrated a capability of imaging regions of cerebral blood flow deficit in MCAO rat brains in vivo using a pinhole SPECT dedicated to small animal imaging.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / diagnostic imaging*
  • Disease Models, Animal
  • Equipment Design
  • Equipment Failure Analysis
  • Image Enhancement / instrumentation*
  • Image Enhancement / methods
  • Rats
  • Rats, Sprague-Dawley
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Stroke / diagnosis*
  • Stroke / veterinary
  • Subtraction Technique / instrumentation*
  • Subtraction Technique / veterinary
  • Tomography, Emission-Computed, Single-Photon / instrumentation*
  • Tomography, Emission-Computed, Single-Photon / methods
  • Tomography, Emission-Computed, Single-Photon / veterinary
  • Tomography, X-Ray Computed / instrumentation*
  • Tomography, X-Ray Computed / methods
  • Tomography, X-Ray Computed / veterinary