A beam of diagnostic X-rays of intensity I0 I_0\,I0 is incident on a layer of soft tissue of thickness ddd. In the absence of a contrast medium, the transmitted intensity through this layer is 0.50 I00.50\,I_00.50I0.
To improve image contrast, a barium-based contrast medium is introduced, which increases the linear attenuation coefficient of this tissue layer by a factor of exactly 3.0.
Assuming the thickness d d\,d remains unchanged, what percentage of the incident intensity I0 I_0\,I0 is transmitted through the tissue when the contrast medium is present?
16.7%16.7\%16.7%
79.4%79.4\%79.4%
12.5%12.5\%12.5%
5.0%5.0\%5.0%
