CZT detector for dual-energy x-ray absorptiometry (DEXA)

摘要

A cadmium-zinc-telluride (CZT) detector has been developed for a bone densitometer that uses dual-energy x-ray absorptiometry (DEXA) to determine bone mineral density in vivo. A linear array of 16 discrete CZT detectors is used with a narrow fan-shaped x-ray beam to scan the patient. Each detector is 3 mm thick and 7 mm * 3 mm in area and has simple planar contacts. The x-ray beam has two broad energy lobes with effective energies of ～38 keV and ～65 keV. The energy sensitivity of the CZT detectors allows discrimination between low and high energy x-rays. Using DEXA, the relative difference in these two count rates permits a quantitative measurement of the areal densities of bone mineral and soft tissue. The detectors demonstrate good performance characteristics and stable operation in a clinical environment. This paper discusses the suitability of CZT for use in DEXA applications and describes its successful implementation and performance in this bone densitometer.