Biomedical Engineering Reference
In-Depth Information
FIGURE 15.9
The method by which the absorption coefficient values for each picture element are obtained.
in Figure 15.9, the first block absorbs a fraction A
l
of the incident photons, the second a fraction A
2
,
and so on, so that the
th block absorbs a fraction A
n
. The total fraction “A” absorbed through all
the blocks is the product of all the fractions, while the logarithm of this total absorption fraction
is defined as the measured absorption. Consider Figure 15.9 once again. The set of absorption
measurements for an object that comprises only four blocks would be as follows:
n
Continued
