RESULTS OF A CLINICAL RECEIVER OPERATING CHARACTERISTIC STUDY COMPARING FILTERED BACKPROJECTION AND MAXIMUM-LIKELIHOOD ESTIMATOR IMAGES IN FDG PET STUDIES

The results of a receiver operator characteristic (ROC) study comparin g maximum likelihood estimator (MLE) reconstructions of human FDG PET brain scan data to filtered backprojection reconstructions of the same data are reported. The purpose of the study was to determine whether MLE reconstructions would result in higher detectability of small foca l lesions introduced artificially into otherwise normal scan data. One physician assisted in defining the location and intensity of the lesi ons and five physicians read the final images. Data from 90 datasets w ere used for the study. Of those, 42 were left in their original ''nor mal'' condition and 48 were modified by added lesions. All datasets we re reconstructed by the two methods and submitted to the five physicia ns for evaluation. The results show an increase in the area under the ROC curve from approximately 0.65 for filtered backprojection to appro ximately 0.71 for the maximum likelihood reconstructions for four of t he five observers with good statistical significance.