RESUMO
A study was made of change of the spectrum (spectral transformation) of x-ray radiation while passing through the soft tissue. Thirty-two depth spectra computed by the Monte-Carlo method and 16 experimentally measured spectra including 9 depth spectra taken from literature, were analysed. A method of the calculation of an absorbed dose in the red bone marrow with account of spectral transformation was described. It was shown that neglect of this factor caused regular underestimation of the assessment of medullary doses, patients were exposed to, during x-ray procedures. The error can reach 40% for doses at local points of the red bone marrow and 1-7% for mean medullary doses with regard to the type of x-ray procedure and regimen of its performance.
