Use of a 4-D cardiac phantom to quantify Karhunen-Loeve images applied to myocardial gated SPECT

Myocardial gated single photon computed tomography (gSPECT) is widely used for quantification of myocardial perfusion and contractile function. Using a modified 4D NCAT phantom, the purpose of this study was to evaluate the diagnostic performance of the Karhunen-Loeve transform (KLT) applied to gSPECT. For this purpose, perfusion was quantified by an index proportional to the size and the intensity of the defect (Pi) and kinetics by an index (Ki) which was the mean endocardial and epicardial wall motion. KLT provides an uncorrelated image series in which only the first two (KL0, KL1) contain the main part of information. It was found that KL0 reflects perfusion and KL1 kinetics