Toward Model-Based Reconstruction in Scanned Baggage Security Applications
While traditional direct reconstruction algorithms such as filtered back projection depend on the analytic inversion of sinogram data, model-based reconstruction methods are based on the iterative optimization of a statistical model of both the acquired data and the unknown image.
Model-based reconstruction offers many important potential advantages over traditional methods of direct reconstruction for the security screening of checked baggage. It has the potential to reduce metal artifacts, improve resolution, reduce artifacts such as cupping that can systematically distort CT number estimates, incorporate tighter integration of reconstruction and segmentation, and support reconstruction from scanners with a small number of projections. All these enhancements have the potential to improve the Pd/Pfa tradeoff for CT security screening systems.
The objective of this research is to investigate and quantify the value of model-based reconstruction for baggage security screening. To do this, our first goal is to implement a general model-based reconstruction algorithm for use on multi-slice helical scan CT scanners and to test and evaluate this algorithm on scans of luggage provided by the ALERT Center. In addition, we will have an ongoing goal of identifying and investigating opportunities for adapting and improving the model-based reconstruction technology for use in security applications. In particular, we will study the use of advanced forward and prior models for reducing metal artifacts, improving segmentation accuracy, and improving CT number estimation.
This structure means that model-based reconstruction algorithms can incorporate both specific details of geometry or physics for the scanner and a statistical characterization of the objects' reconstruction.F3-A5 Project Overview: ALERT Year 4 Annual Report
Charles A. Bouman
Faculty and Staff Currently Involved in Project
Notre Dame University
Students Currently Involved in Project
- Pengchong Jin
- Eri Haneda