A New Approach to Reduce CT Scan Time and Cost

Additive Manufacturing processing adds flexibility to the US manufacturing base, allowing rapid production, optimized designs, and sustainment solutions. This evolving technology also requires a new flexible inspection technique. Nondestructive evaluation (NDE) with computed tomography (CT) is an attractive inspection option; however, time and cost restrictions have limited the feasibility of CT as a full-scale inspection solution.

EWI recently developed an advanced methodology that produces high-quality reconstructions using a fraction of the scan images required by traditional algorithms. Depending on part geometry, proof-of-concept work has achieved a 3x-10x scan-time savings and demonstrated the potential to greatly reduce the cost of inspection and qualification with CT. Reduced scan time is achieved by integrating prior knowledge in the reconstruction process. Because the methodology is software-based and is executed during computation time, this inspection technique is hardware agnostic and has the potential to be implemented in any existing setup.

The faster-CT methodology has its basis in the iterative reconstruction techniques developed by Gordon, Bender, and Herman. The main advantage of this technique over the FDK algorithm is the ability to integrate information about the scanned part into the algorithm at any point prior to or during reconstruction. By incorporating known details about the part before manufacture, we can maintain similar reconstruction quality to traditional methodologies while reducing the number of scan images. Furthermore, iterative techniques allow access to information on a pixel-by-pixel or voxel-by-voxel basis during reconstruction. This level of detail will contribute to the development of advanced metrics for determining the accuracy of and confidence in the reconstruction.