Figure 7.

Transformation pairs in the opposite direction (e.g. non-aligned CT→MR and MR → non-aligned CT) were composed together and a single baseline CT was transformed under this composition. Given perfect inverse consistency, the original image should be recovered. The mean square error (MSE) was calculated between the original and transformed CT for the direct and synthetic CT bridged registrations, and in both directions. The boxplot bars show 5–95% range. A paired T-test was performed to evaluate significant difference.