Comparison of two optimizing algorithms for cerebral blood flow analysis using the intravenous 133Xe wash-out method

The analysis of cerebral blood flow data using intravenous injection and inhalation of 133Xe requires a correction for the arterial recirculation. With a multi-exponential transfer function a problem exists in estimating the non-linear parameters. In this paper conventional two-compartmental blood flow indices from the intravenous 133Xe clearance method are calculated using Marquardt and variable metric optimizing algorithms. Close agreement was found between these two methods in that they yield similar values for the cerebral transfer function.