The extraction of 3D dimensional measurements based on a limited number of 2D X-ray radiographs of a part would offer a significant speed up of quality control procedures in industry. However, there are challenges with respect to both measurements and uncertainties. This work addresses these questions by creating an estimated numerical model of the imaged part, on which dimensional measurements can be made. The numerical model is chosen as a parametric deformation model that encodes the expected variability of the part shape resulting from the manufacturing process. The parameters and uncertainties of the deformation model are estimated by the registration of the computed projections of the model and the observed radiographs. The proposed approach is applied to the NDE of turbine blades manufactured by investment casting, and in particular to the measurement of their wall thickness, which is a critical element. The deformable model consists in partitioning the inner ceramic core into multiple subparts, which may undergo a rigid body motion with respect to the master die. Wall thickness measurements are determined from the estimation of these rigid body motions. To assess the reliability of the proposed procedure, a repeatability study is performed, as well as a direct comparison with ground truth measurements from a reconstructed tomogram. Both of them show that such measurements are reliable and efficient. Furthermore, residual differences between captured and computed projections reveal localized shape deviations from the CAD model, meaning that despite localized model errors, the approach is operable.