Original CT image
+ Region Of Interest (ROI)

7x ROI
before enhancement

7x ROI
after enhancement

7x ROI
after enhancement
with annotation for measurements

(a) Mean Intensity within outlining = 33 ± 12 units;
(b) Area = 188.31 ± 1.52 mm²; and,
(c) Volume (slice-thickness * area) = 564.93 ± 4.56 mm³.

Areas (& volumes) of multiple slices may be used for the oncology treatment monitoring.