Elastic surface contour detection for the measurement of ejection fractionin myocardial perfusion SPET

The aim of this study was to investigate the use of an automated three-dime nsional myocardial contour detection method using elastic surfaces for the assessment of left ventricular ejection fraction (EF) from electrocardiogra phically (ECG) triggered myocardial perfusion single-photon emission tomogr aphy (SPET). The validity of this method was studied on the basis of both p hantom measurements and patient studies. Phantom measurements were performe d using an elastic phantom of the left ventricle simulating a beating heart , with a simulated EF ranging from 10% to 78%. The data from 27 patients wh o had undergone both EGG-triggered myocardial perfusion SPET and planar gat ed radionuclide ventriculography (RNV) were used to compare the EF derived from the SPET data with the automated contour detection method and the EF d erived from the RNV data with standard analysis software. EF values as meas ured by RNV ranged from 11% to 68%. The overall accuracy of the automated c ontour detection method proved to be very high. In the phantom study the de viation of the measured EF from the reference values was less than 4% for a ll of the simulated EFs. The studies on the patient data yielded a correlat ion coefficient (Pearson) greater than 0.94 as compared with planar RNV. In tra- and inter-observer reproducibility was high, with correlation coeffici ents exceeding 0.97. It is concluded that the proposed method allows accura te, reproducible and fast measurement of the left ventricular EF on the bas is of myocardial perfusion SPET.