Comparison of radiation dose and cancer risk between conventional polychromatic imaging and gemstone spectral imaging in computed tomography (CT) examination: a phantom study

Abstract

This study aims to measure the radiation doses and estimate the associated lifetime attributable risks (LARs) of cancer incidence resulted from gemstone spectral imaging (GSI) and conventional polychromatic imaging (CPI) in computed tomography (CT) examinations. Organ doses were measured using an adult phantom and thermoluminescent dosimeters. Four scans, including head CT, thorax CT, abdomen CT and pelvis CT, were performed on the phantom. LARs of cancer incidence were estimated for Chinese population and US population. The effective doses of thorax CT was the highest. With CPI, it was 7.94 mSv for females, and 7.74 mSv for males. With GSI, it was 6.81 mSv for females, and 7.69 mSv for males. With GSI, the corresponding LARs for males and females aged 20-70 years were less than 0.062% and 0.154%, respectively. With CPI, these values were less than 0.074% and less than 0.171%, respectively. The LARs decreased in both US population and Chinese population when exposed age increased, with thorax scan causing the highest risk. GSI does not increased radiation exposure or cancer risk compared to CPI. These findings may allow the application of GSI in patients referred for CT.