A Study on Physiological Parameter Estimation Accuracy for Tracer Kinetic Modeling with Posttron Emission Tomography (PET)

Tracer kinetic modeling with Positron Emission Tomography requires measurements of the time-activity curves in both plasma (PTAC) and tissue to estimate physiological parameters. Ideally, this PTAC should be the tracer local capillary plasma time-activity curve (CPTAC). However, due to the inaccessibility of direct measurement of CPTAC, the arterial plasma time-activity curve (APTAC) is usually used to replace CPTAC. The range of physiological parameter estimation errors caused by this replacement is not clear yet. In this paper, CPTAC is derived from the APTAC measurement and a 4-compartment PTAC model [2]. This CPTAC is then used to study the effects of using APTAC to replace CPTAC and APTAC measurement errors on the estimation of the physiological parameter. The results show that using APTAC directly in parameter estimation can cause considerable biases and increase the uncertainty of parameter estimation.