Source of Support: None, Conflict of Interest: None
Computed tomography contributes a significant fraction to population exposures. In the present study, organ doses and effective doses, normalised to the air kerma along the axis of the phantom are estimated using Monte Carlo method. A computer code MCNP (Version 3.1) and a mathematical phantom developed for this purpose are used in this study. A source sub-routine is prepared to treat the rotation of the x-ray source and restrict the beam to slice thickness. This paper presents normalised organ doses and effective doses, in head and spine CT examinations for an average Indian adult.