Patient-Specific Dose Estimates in Dynamic Computed Tomography Myocardial Perfusion Examination

Abstract

The study aimed to implement realistic source models of a computed tomography (CT) scanner and Monte Carlo simulations to actual patient data and to calculate patient-specific organ and effective dose estimates for patients undergoing dynamic CT myocardial perfusion examinations. Source models including bowtie filter, tube output and x-ray spectra were determined for a dual-source Siemens Somatom Definition Flash scanner. Twenty CT angiography patient datasets were merged with a scaled International Commission on Radiological Protection (ICRP) 110 voxel phantom. Dose simulations were conducted with ImpactMC software. Effective dose estimates varied from 5.0 to 14.6 mSv for the 80 kV spectrum and from 8.9 to 24.7 mSv for the 100 kV spectrum. Significant differences in organ doses and effective doses between patients emphasise the need to use actual patient data merged with matched anthropomorphic anatomy in the dose simulations to achieve a reasonable level of accuracy in the dose estimation procedure.

The impact of vertical off-centering on image noise and breast dose in chest CT with organ-based tube current modulation: A phantom study

“…bowtie filter, spectra and helical scan exposure geometry), material conversion, and the anthropomorphic phantom model. According to a previous study with similar methodology, the maximum difference between dose measurement and simulation results was found to be around 15% as applied to phantom data with ImpactMC program incorporating bowtie filter and spectra models [49]. Higher uncertainties can be anticipated if simulations are performed for clinical patient data with individual morphology, organ locations and shapes.…”