  We report on the measurements performed using a 22Na source on a detector
element for an MRI-compatible TOF-PET endorectal prostate probe, with
Depth-Of-Interaction sensitivity. It is made from a LYSO scintillator crystal,
wrapped with Lumirror, readout at both ends by means of Silicon
Photomultipliers. With a detailed description of the data analysis procedure we
show that our results point to a 400 ps coincidence resolving time and, at the
same time, to a Depth-Of-Interaction resolution of 1 mm. These appealing
features, along with the tiny 1.5 mm x 1.5 mm x 10 mm crystal size, are quite
promising in view of the realization of a prototype probe.
