PHYSICS · Subjective · Fermi University Physics · Nuclear Physics · Biophysics & Medical Physics · Radiation interactions, detection and dosimetry
Life at Thermal Energy, Ch Images from attenuation and from decay
Problem
Over one year, a patient under follow-up for a past cancer receives two chest radiographs (0.02mSv each), one chest CT (7mSv) and one bone scan (4mSv), the typical effective doses given in this chapter. Natural background radiation is about 2.4mSv per year, and the nominal stochastic risk of a fatal or serious radiation-induced effect is about 0.05 per sievert of effective dose. (a) State the assumptions your estimate needs. (b) Add the effective doses to estimate the patient's total dose from imaging that year. (c) Express this total as a multiple of one year's natural background. (d) Estimate the nominal added risk this year of imaging carries, and express it as "about 1 in N".