Fig. 12
Comparison between linear and volumetric measurements of small renal mass (SRM) growth over a 6-month period. Upper- and bottom-left: axial contrast-enhanced CT showing a renal mass with MTD 3.9 cm at the beginning of AS and 5.3 cm in the next study 6 months later with a linear GR of 1.4 mm between the two studies corresponding to a linear GR of 3.8 cm/year (arrows). Volumetric representation of the renal mass in an axial plane (thick arrows) (upper- and bottom-middle) and coronal plane (arrowheads) (upper- and bottom-right). The software showed an initial volume of 21 cc and a final volume of 53 cc. The increase in volume was 32 cc, indicating that the mass had doubled in volume over a 6-month period representing a rapid growth, although there are no established volume values to define progression