A BPF reconstruction algorithm for CBCT with a half-size flat panel detector

Flat-panel detectors (FPDs) have emerged as the next generation digital X-ray technology. They are more sensitive, faster and cheaper than film. Nowadays, FPDs are widely used in industrial radiography and medical imaging. We design an experimental dental cone-beam CT (CBCT) system using a small size FPD off-center placed. The field of view (FOV) of detector can cover only half of the scanned object in every scan angle. Typical FDK reconstruction algorithm is not available in this system because of transversely truncated projections. A 3D BPF-type reconstruction algorithm using a modified finite Hilbert transform method is researched for this kind of CBCT system with off-center half-size FPD. This reconstruction method is validated by simulation study and practical experiments with an anthropomorphic tooth phantom. We compare the reconstruction results with the other methods. The preliminary experiment results prove its feasibility in reconstruction of CBCT with transversely truncated projections.