Study of Phantom Images with Silicone Rubber on Single Photon Emission Computed Tomography (SPECT)

Silicon rubber has been used as a protective material to shield sensitive organs of patients located near the skin surface during CT scan examinations. However, the quality of the resulting images has not been thoroughly investigated. This study was to evaluate the resulting image quality of a new synthetic thyroid shield based on silicon rubber (SR)-lead (Pb) composites thyroid shields in single photon emission computed tomography (SPECT) examination of the neck phantom. The synthetic SR-Pb thyroid shield had a Pb percentage from 0 to 5 wt% and a thickness of 0.6 cm. Scanning on the neck phantom was performed with and without the SR-Pb. The thyroid shields were placed directly on the neck surface. Image quality was characterized by spatial resolution on the areas of anterior, posterior and lateral of the neck phantom. Detailed evaluation of the image quality was employed by image subtraction. The SR-Pb shield produced only a very small artefact, increasing spatial resolution in the posterior area by only 9%. The SR-Pb shield is suitable in the daily clinical setting for thyroid in SPECT examinations while maintaining image quality.