Karhunen-Loeve transform for analysis of cardiac function in myocardial gated SPECT

摘要

Myocardial gated SPECT (gSPECT) is widely used to evaluate different parameters of cardiac function. Semi-quantitative analysis of the images (a visual analysis of the images with a simple scaling of function) can be performed after image segmentation using 4-or 5-point scale. The purpose of this study was to compare two functional images (KL0 and KL1) obtained by KLT (Karhunen-Loeve transform) and "clinical" images of gSPECT and to test feasibility of semi-quantitative analysis of perfusion and contraction by KLT. 99mTc-gSPECT studies were performed in 105 patients with suspected coronary artery disease. We performed visual and semi-quantitative analysis of gSPECT and KLT images (KLT was applied to images from central slices of 3 axes). Our results showed that KLO images match with myocardial perfusion images; KL1 images combine the data on spatial and temporal evolution of each pixel and regroup pixels by families. We suggest that opposite parts of KL1 images characterize two components of myocardial contraction: wall motion and thickening. These preliminary results showed relations between KLT images and myocardial function: KLO images and myocardial perfusion, KL1 images and cardiac mechanics. These findings prove the potential of KLT for yielding additional useful clinical information.