Noninvasive estimation of quantitative myocardial blood flow with Tc-99m MIBI by a compartment model analysis in rat.

BACKGROUND

We aimed to investigate the use of dynamic cardiac planar images to estimate myocardial blood flow (MBF) by a compartment model analysis using time-to-peak (TP) map and compared it by the microsphere technique in rat. Positron emission tomography is considered the gold standard method, but is not available everywhere. By contrast, although myocardial perfusion imaging (MPI) with single-photon tracers is more widely available, it may be difficult to obtain adequate region of interest (ROI) settings. We proposed using the TP map to set the ROI, and hypothesized that this method could facilitate the measurement of absolute MBF by MPI in rat.

METHODS

Twenty-one normal rats were studied. Dynamic planar images with Tc-99m MIBI were obtained, and input function and cardiac ROIs were set using the obtained TP map. MBF was estimated by a one-compartment model analysis with the Renkin-Crone model and by the microsphere technique.

RESULTS

The MBFs from these two methods were significantly correlated. A negative proportional bias was observed, but no significant difference was observed between the mean MBFs calculated with each method.

CONCLUSIONS

MBF estimation by a compartment model analysis using TP map could facilitate absolute MBF measurement in rats.