A new method for quantitative analysis of gated SPECT polar scintigraphic maps

We have developed a software, which allows to do non conventional percent quantitative analysis on scintigraphic polar map obtained from conventional processing of gated-SPECT acquisitions. Polar maps are 8 bit images of perfusion, motion, ejection fraction (EF) and thickening, of the heart The software is written in Matlab, analyses the whole polar map and four ROIs corresponding to the theoretical LAD, LCX, RCA territories (perfused by these arteries) and extra-ROIs region. An intensity segmentation is performed. The area corresponding to pixels lower and higher than a varying cut-off are calculated on the whole image and for each ROI. The software calculates an intensity-area histogram, which is the analogous of the Dose-Volume Histogram used in radiation therapy: in this case, the histogram has the meaning of a Perfusion- or a Motion-Volume histogram. Then, the software applies the Lyman-Wolbarst algorithm, to calculate the area equivalent histogram reduction (e.g. the perfused area in the hypothesis that all pixels are perfused at 100%.). The makes a direct comparison between two different polar maps by choice. The comparison between the numerical quantification of motion and perfusion maps, allows the physicians to get a clinical evaluation of the stunned myocardium.