Conjoint use of coded-aperture collimators and MLEM algorithm: Towards large blood vessels reconstruction at 511 KEV

In this paper, we propose a novel approach to improve the trade-off between the spatial resolution and the sensitivity of existing nuclear imaging systems in emission tomography for 511 keV-photons. Although emission tomography suffers from the low amount of emitted photons in the object, partial transparency of collimators and low sensitivity of detectors, we are able to reconstruct radioactive spatial distribution from projections obtained through a specifically designed coded-aperture collimator, with a MLEM-algorithm. We address both the selection of the collimator and the reconstruction approach. Very promising experiments towards 3D-vessels reconstruction demonstrate the potentials of our approach.