Method for estimating radiation dose received by a tissue of interest during an imaging scan comprising: i, obtaining image data of a body region including the tissue of interest, ii. sub-dividing the image data into axial slices, comprising tissue axial slices and non-tissue axial slices, iii. determining a net amount of radiation dose emitted or received by each axial slice by combining scan parameters of each axial slice with pre-calculated amounts of radiation dose, iiii summing the net amounts of radiation dose of all the tissue axial slices to obtain a tissue dose.