RT Journal Article SR Electronic T1 A Modified FORTRAN Program for the Calculation of Modulation Transfer Function JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1238 OP 1240 VO 18 IS 12 A1 Ralph Neff A1 Dick Hoops A1 Guy Simmons YR 1977 UL http://jnm.snmjournals.org/content/18/12/1238.abstract AB