Three-Dimensional Radiopharmaceutical-Excited Fluorescence Imaging of Lymph Nodes

Optical imaging techniques have been developed for localizing lymph nodes before surgical resection due to the non-invasion and high sensitivity. However, its attendant penetrability limitations and auto-fluorescence effect have greatly limited the spatial resolution and imaging precision. In this study, a novel technique radiopharmaceutical-excited fluorescence imaging (REFI) was adopted to image lymph nodes, which use gamma-ray and Cerenkov radiation from radioisotopes to excite lanthanide europium oxide (EO) nanophosphors and boost the light intensity. An effective adaptive-steepest-descent-projection onto convex sets (ASD-POCS) reconstruction algorithm and the anatomic structure information were used to three-dimensionally image lymph nodes in mice models. The results indicate that REFI can greatly boost the light intensity and accuracy of threedimensional imaging of lymph node with location deviation less than 1.03 mm.