Local lung tissue expansion analysis based on inverse consistent image registration

This thesis work describes a technique to estimate local lung tissue expansion using non-rigid inverse consistent image registration on multiple respiratory-gated CT images of lung acquired at different inflation levels. The information of local lung tissue expansion is revealed by the Jacobian of transformation, intensity-based specific volume change, and strain resulted from the registration displacement field. Comparisons between the registration-derived regional lung expansion estimates and xenon CT-derived regional ventilation measure on six sheep at supine position were made to validate the estimates based on registration and find the suitable inflation level change to characterize the lung expansion using this technique.