Quantitative imaging of myocardial infarct in rats with high resolution pinhole SPECT

Int J Cardiovasc Imaging. Jun-Aug 2006;22(3-4):429-34. doi: 10.1007/s10554-005-9046-7. Epub 2006 Mar 4.

Abstract

Small animal imaging of cardiovascular disease using single photon emission tomography (SPECT) can be used to provide quantitative measurements of myocardial infarct. The purpose of this study was to demonstrate the accuracy of pinhole SPECT imaging with [99mTc]sestamibi for estimation of infarct size in a rat model of coronary artery disease. Nine rats had their left anterior descending artery ligated to induce a region of myocardial infarct. These animals were injected with 37 MBq [99mTc]sestamibi, and, 1 h later, scanned on a pinhole SPECT system for 30 min. The defect size measured with SPECT, which was dependent on a threshold applied to the short axis circumferential profiles, was compared against the gold standard triphenyltetrazolium chloride (TTC) staining. The size of the perfusion deficit measured using [99mTc]sestamibi SPECT compared very favorably with the TTC staining result, for threshold values in the range 50-70%. The optimum threshold was approximately 70%, giving an excellent correlation (R2=0.89, p<0.001). Estimation of infarct size by [99mTc] sestamibi SPECT yielded an excellent agreement with TTC staining. In conclusion, measurement of myocardial infarct with SPECT can be used to study the rat heart in vivo, and provides a quantitative measure of myocardial viability.

Publication types

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

MeSH terms

  • Animals
  • Coronary Artery Disease / complications
  • Coronary Artery Disease / diagnostic imaging*
  • Coronary Artery Disease / pathology
  • Disease Models, Animal
  • Image Interpretation, Computer-Assisted
  • Indicators and Reagents
  • Male
  • Myocardial Infarction / diagnostic imaging*
  • Myocardial Infarction / etiology
  • Myocardial Infarction / pathology
  • Myocardium / pathology
  • Radiopharmaceuticals
  • Rats
  • Rats, Sprague-Dawley
  • Reproducibility of Results
  • Technetium Tc 99m Sestamibi
  • Tetrazolium Salts
  • Tomography, Emission-Computed, Single-Photon* / methods

Substances

  • Indicators and Reagents
  • Radiopharmaceuticals
  • Tetrazolium Salts
  • triphenyltetrazolium
  • Technetium Tc 99m Sestamibi