Experimental test of double-layer method for industrial spect

In industrial-type single-photon-emission computed tomography (SPECT) systems, the use of relatively large detectors and collimators for effective detection of highenergy gammas significantly limits imaging performance, primarily because of insufficient measurement points. In the present study, a simple but very effective image-quality improvement method, the double-layer method, was tested. In this method, two layers of identical SPECT systems are employed in order to increase the number of measurement points and, thereby, improve the image quality. For experimentation, the two identical detector layers were arranged for 30 deg of rotation with respect to each other. The results showed that the double-layer method indeed significantly improves the image quality of the industrial SPECT system, substantially reducing errors in source size and location for both low-energy (^99mTc) and high-energy (^113mIn) gamma sources.