Studying the lung dose uncertainty during chest CT scans using phantoms with statistical lung volumes and shapes.

In recent years, there has been a growing interest in constructing a series of deformable phantoms, which follow statistical distributions of some anatomical variations, called "statistical phantoms". The main purpose of this study was to develop statistical phantoms by considering the variations of lung volume and shape, to evaluate the lung dose uncertainty for individuals undergoing chest computed tomography. Calculations were performed for 100 statistical lung volume phantoms and 70 statistical lung shape phantoms at tube voltage of 80 and 120 kVp with the use of Monte Carlo MCNP code. Obtained results indicate that dose fluctuations for low tube voltage (80 kVp) are higher than those at 120 kVp. Moreover, it shows that the impact of statistical variations of lung volume on dose discrepancy (5% to 7%) is higher than the impact of statistical lung shape variations (around 2%).