A useful method of evaluating observer consistency anil accuracy in radio. nuclidc picture image interpretation is presented. The results of this study indicate that ROC curves reflect a useful statistical evaluation of observer responses. A test scries is presented which indicates that transmission of radionuclide picture images over a Picturephone does not degrade the diagnostic quality of the images nor lead to incorrect interpretation. Our study utilized a transmission system different from that used by other workers, who have reported results in conflict with the present findings.