Basic study of one-shot dual energy subtraction sialography: Evaluation method of optimal conditions

摘要

The author produced a bone-iodine step (BI-step) phantom and performed a basic experiment using it in one-shot dual energy subtraction sialography by computed radiography (CR). There are many parameters of energy subtraction such as the tube voltage, filter, Imaging Plate (IP), grid, contrast medium, and image processing. In this study, the author evaluated the influence of tube voltage (50 ∼100 kVp), copper (Cu) and tin (Sn) filters, and the iodinated contrast medium on the resultant image. The conditions of optimal subtraction were theoretically determined, and the separation between bone and iodine reached a maximum at a tube voltage of 50kVp with a Cu-filter of 0.8 mm in this investigation. The correctness of these conditions were confirmed on actual subtraction images. These results appear to be applicable to digital subtraction sialography following a further combination with the other parameter