In this paper, we propose to investigate and analyze a new method for performing quantified projection and back-projection in emission tomography. This method is based on using non-summative kernels, capacities and asymmetric Choquet integral to obtain imprecise projected values (i.e. intervals instead of usual reconstructed pixel values). Validation studies using numerical and physical single photon computed emission tomography (SPECT) phantoms were used to demonstrate links between the length of these reconstructed intervals and the stochastic noise level in reconstructed slices.