Performance standards in positron emission tomography - Karp, JS; Daube-Witherspoon, ME; Hoffman, EJ; Lewellen, TK; Links, JM; Wong, WH; Hichwa, RD; Casey, ME; Colsher, JG; Hitchens, R; Huehllehner, G; Stoub, EW (J Nucl Med, 1991)