Cone-beam SPECT with a tilted detector.

In this article we report on the TOMOCONIC project for cerebral SPECT using cone-beam collimators. First, we describe our experimental set-up. The cone-beam collimator improves both spatial resolution and sensitivity. We tilt the detector to center the focal point rotation plane on the region to reconstruct. Then, to minimize cone-beam artefacts, we use the Grangeat algorithm for image reconstruction. We describe here how it can be generated to this tilted acquisition geometry. Finally, we present our first experimental results and a comparison with parallel-beam SPECT. The improvement ratio on transverse spatial resolution is 1.5. We conclude with our first clinical images.