Fig. 1

Schematic representation of the x-ray emission and absorption spectra related to the use of ICM during a CT session. a Relative emission x-ray spectrum of a typical 120 kVp CT scan. The arrow indicates the 33.2 keV component of the spectrum that would correspond to the K-edge of iodine. Iodine b and water c mass energy coefficients μ_en/ρ expressed in cm².g^− 1 as a function of energy. d Relative energy absorption of iodine in water (normalised ratio between the relative iodine and water mass energy absorption coefficients μ_en/ρ) as a function of energy. e Product of the relative emission intensity of a typical 120 kVp CT x-ray tube and the relative absorption of x-ray by ICM