Feasibility study: Low-cost dual energy CT for security inspection

Dual energy CT (DECT) has become a hot topic among security inspection recently for its high detection precision and robust material identification ability. Currently, in one typical realization of DECT, two sets of detectors are needed. However, the high cost of the system become a big limitation for its wide usage. Moreover, in some particular situation, the detective objects detected in security inspection with regular shapes and thicknesses don´t need complete sampling to reconstruct. Therefore, a new idea of system setup, dual energy CT with reduced data system (DECT-RDS), only a few detector bins instead of complete-sample bins of the second high energy set which can greatly reduced the cost, had been created. And then, we proposed a new dual energy CT reconstruction method with reduced data (DECT-RD) requiring much fewer data to reduce the cost of detectors. In this paper, to fully investigate the feasibility of its application in security inspection, we are developing such an experimental imaging system (DECT-RDS). Practical experiments are done by using only 20% detector bins instead of complete-sample bins in each projection. Results give a relative error less than 5% between complete sampling and undersampling. The results demonstrated that detector bins can be greatly reduced in dual energy CT imaging, hence much lower the system cost. We believe this type of system configuration will drive DERT into wide practical applications.