Experimental Evaluation of Spectral-Temporal-Double-Coincidence-Enhanced Preclinical SPECT Imaging of Low-Dose Therapeutic Radionuclides

We proposed the spectral-temporal double coincidence (STDC) technique to enhance SPECT imaging of therapeutic radionuclides emitting cascade photons, such as Lu-177, Ac-225, and In-111. The preliminary simulation study explored the potential that STDC could reject >99.9% of down-scattering contamination with a high timing resolution system. To experimentally evaluate the technique, a prototype STDC-SPECT system was constructed using 3D CZT detectors. The reconstructed images of a line-source demonstrated the dramatic enhancement of the image quality with STDC-SPECT compared to conventional SPECT data acquisition. These results have demonstrated the potential of STDC-enhanced SPECT imaging for low-dose therapeutic radionuclides in small animals.