Investigation of the physical aspects of beta imaging probes using scintillating fibers and visible light photon counters

The authors are developing a hand held imaging probe intended for intraoperative use. This probe is to be used after the bulk of tumor has been removed. It will locate residual malignant tissue labeled by a pre-operative injection of a tumor seeking radiopharmaceutical. The device presented here is a prototype system that consists of a 4×8 array of 925 μm diameter plastic scintillating fibers. The imaging array is coupled to visible light photon counters via 2 meters of optical fiber. The authors have obtained an intrinsic spatial resolution of 1.0 mm with a highly collimated beta source, and a 2.0 mm resolution with a 1 mm, uncollimated source. Standard deviations of the relative gain and sensitivity over the 32 imaging elements were found to be 9.6% and 11.7% of the mean, respectively