Developing a dual energy X-ray absorptiometry (DEXA) system using SrI2:Eu2+ coupled to silicon photomultiplier (SiPM)

Abstract

This paper presents the evaluation of an alternative solution for detectors of dual energy x-ray absorptiometry systems. Bone mineral density (BMD) evaluation tools are crucial to the proper diagnosis of osteoporosis. The commercially available DEXA systems utilize CZT as the detector of the small dose of ionizing radiation passing through the area of interest. Our paper presents a novel Strontium Iodide doped with Europium (SrI2:Eu2+) scintillator crystal coupled to a Silicon Photomultiplier (SiPM) array as a less expensive alternative to CZT detector. Dual energy (60 keV and 122 keV) exposure was used for BMD measurements of a bone phantoms containing CaHPO4 to mimic bone and resin to mimic soft tissue. Calibration curves was determined for both BMD and for thickness measurements, validated by “unknown” phantoms. Both calibration curves lead to decreased errors compared to commercially available systems.