Erratum

Quantification of Human Opiate Receptor Concentration and Affinity Using High and Low Specific Activity [ 11 C]Diprenorphine and Positron Emission Tomography Bernard Sadzot, Julie C. Price, Helen S. Mayberg, Kenneth H. Douglass, Robert F. Dannals, John R. Lever, Hayden T. Ravert, Alan A. Wilson, Henry N. Wagner, Jr., Marc A. Feldman, and J. James Frost [originally published in Journal of Cerebral Blood Flow and Metabolism 1991;11(2):204–219] Due to errors in the PET calibration factors, the published values of some of the parameter estimates are inaccurate. The correct values of Bmax and KD are 1.4 times and 0.4 times the published value, respectively. The correct values of Kl and Ktfk2 are 3.2 times the published value. Accordingly, the values of konf2 and f2 are 0.7 and 0.3 times the published value, respectively. The values of k2′ k3′ and k4 are correct. These quantitative errors in the parameter estimates do not affect the overall strategy for the application of tracer kinetic modeling nor the identification of the optimal fitting strategy. The authors regret these errors.