Simultaneous Estimation of input functions: The B-SIME method

Using Positron Emission Tomography for dynamic tracer mapping requires the knowledge of the arterial plasmatic activity concentration (PTAC). The reference method to obtain it is arterial sampling, not applicable in clinical studies because invasive and dangerous. The Simultaneous Estimation (SIME) method aims to estimate simultaneously the PTAC and the organ pharmacokinetic parameters from the time-activity curve of some tissues (three or four), with or without the help of some blood samples. The improvement proposed here, the B-SIME method, uses the results of the SIME on hundreds of sets of three tissues to evaluate the PTAC. Here an application for the ¹⁸F - FDG in human brain is shown; good results for the estimation of the PTAC were obtained, specially when using one late venous blood sample, for simulated and real data.