Sensitivities of CBF to the appearance time error. Results of the simulation study demonstrating the effects of different appearance time of the arterial input function on the cerebral blood flow (lines) and on the calculated mean (plots) and SD (error bars) of CBF from the noisy TAC. The assumed CBF value was 0.5 ml/min/g. Positive and negative values of errors in delay time indicate earlier and later appearance, respectively. Results are plotted for the autoradiography (ARG), the basis function methods with fixing partition coefficient (BFMF), the basis function methods without fixing partition coefficient (BFMP), and ATB correction (BFMAT).