RT Journal Article SR Electronic T1 A Contrast Efficiency Function for Quantitatively Measuring the Spatial-Resolution Characteristics of Scanning Systems JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 53 OP 60 VO 11 IS 2 A1 Rollo, F. D. A1 Schulz, A. G. YR 1970 UL http://jnm.snmjournals.org/content/11/2/53.abstract AB