Real-time 3D cone beam reconstruction

• Published in: IEEE Symposium Conference Record Nuclear Science 2004 Vol. 6; pp. 3648 - 3652 Vol. 6
• Main Authors: Stsepankou, D., Kommesser, K., Hesser, J., Manner, R.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2004
• Subjects: Bandwidth; Degradation; Field programmable gate arrays; Graphics; Hardware; Image reconstruction; Iterative methods; Parallel processing; Reconstruction algorithms; Subspace constraints
• ISBN: 9780780387003; 0780387007
• ISSN: 1082-3654; 2577-0829
• DOI: 10.1109/NSSMIC.2004.1466673

The paper presents a comparison of filtered back-projection and iterative approaches (modified SIRT and OSEM) where backprojection is performed on FPGA hardware and forward projection is realized by a graphics card. The FPGA-architecture allows scaling parallel processing of the backprojection with a constant memory bandwidth and it performs its task about a factor of 6 faster than conventional graphics card architectures (using a Xilinx Virtex II 6000 compared to a floating-point implementation on a graphics hardware). For the forward projection a graphics card (with NVIDIA GeForce FX 5900) is used. The system reconstructs a volume of 256/sup 3/ voxels and 60 projections (5122) within 6 seconds for each backprojection step and 12.5 s for the forward projection. As assumed filtered backprojection is the fastest method but shows most artifacts. SIRT and OSEM generate results with suppressed artifacts and require between 4 (SIRT) and 3 (OSEM) minutes for reconstruction. The limited precision of on the FPGA does not lead to any degradation in the reconstructed image quality.