Direct estimation of kinetic parameters from the sinogram with an unknown blood function

Kinetic parameter estimation using PET is an important tool for quantification of the acquired image. Often a known blood function is assumed and the parameters are estimated using reconstructed PET images. However, obtaining blood function using arterial sampling or estimating it from a region in the PET image has certain disadvantages. In this paper, we present a method to estimate the kinetic parameters directly from the sinogram without requiring the knowledge of the blood function. Using the sinogram instead of the reconstructed images is expected to yield statistically efficient estimates, because the physical model of the imaging system and the statistical noise are handled in a single framework. Computer simulations show that the proposed method can obtain accurate estimate of the kinetic parameters