Estimating Specific Patient Organ Dose for Chest CT Examinations with Monte Carlo Method

Purpose: The purpose of this study was to preliminarily estimate patient-specific organ doses in chest CT examinations for Chinese adults, and investigate the effect patient size on doses. Methods: By considering body-size body-build effects taking mid-chest water equivalent diameter (WED) as a indicator, scan images 18 adults were acquired multi-detector generate regional voxel models. For each patient, lungs, heart, breasts (glandular breast tissues both breasts) segmented, other organs semi-automated segmented based their HU values. scanner models simulated by MCNPX 2.4.0 software (Los Alamos National LaboratoryLos Alamos, USA) used calculate lung, breast, heart CTDIvol values normalize doses, exponential estimation model between normalized dose WED investigated. Results: Among patients study, 18.15 ± 2.69 mGy, 18.68 2.87 16.11 3.08 respectively. Larger received higher than smaller ones due tube current used. ratios 1.48 0.22, 1.54 0.20, 1.41 0.13, all three decreased with increase WED, more obviously lung that breasts. Conclusions: output under ATCM is positively related attenuation patients, larger-size receive negatively correlated size. could be estimated using indicated combined WED.