Fig. 10.
Effect of increased dispersion of input function on parameter estimates for noisy pseudodata. A: narrowest and broadest of 13 lagged normal density functions used as vascular inputs (left ordinate) and their corresponding noise-free residue solutions (right ordinate). Peak of narrowest input is truncated. B: estimates of flow (left ordinate) and VSV (right ordinate) obtained by fitting noisy pseudodata with use of corresponding inputs, dispersion of which is shown on abscissa, relative to dispersion of microvascular system, which was constant. Values are means ± SD of fits of 10 independent realizations of each set of noisy pseudodata. Horizontal lines, true values of flow and volume. Increased input dispersion caused increased variability in parameter estimates, particularly flow, but did not cause any systematic error. RDinput, relative dispersion of vascular input; RDsystem, relative dispersion of microvascular system for impulse input.