DOI- and TOF-capable PET array detector using double-ended light readout
and stripline-based row and column electronic readout
Abstract
We investigate an economic readout for depth-of-interaction (DOI) and
time-of-flight capable PET detector that consists of an N×N array of
crystals whose light outputs at the front- and back-end surfaces are
detected by using silicon photomultipliers (SiPM). The N×N SiPMs at the
front-end (back-end) of the detector are read by a stripline configured
to support discrimination of the row (column) position of the
signal-producing crystal, producing only four outputs for the detector.
To evaluate this design, we built 4×4 and 8×8 detector modules (DM) by
using 3.0×3.0×20 mm3 lutetium-yttrium oxyorthosilicates. The outputs
were sampled at 2 GHz and processed offline. For both DMs, crystal
discrimination was successful. For the 4×4 (8×8) DM, we obtained a
crystal-level energy resolution ranging from 11.3% to 19.3% with an
average of 14.1% (9.5% to 21.6% with an average of 13.9%), an
average DOI resolution of 2.5 mm (3.1 mm), and a best coincidence
resolving time (CRT), measured in coincidence with a single-pixel
reference detector with a 302 ps CRT, of 391 ps (603 ps). The CRT
deteriorated with the (8×8) DM possibly due to intercrystal scattering.