Total variation minimization-based spiral CT reconstruction in a dental panoramic imaging system for cost-effective, low-dose dental X-ray imaging

In the paper, we proposed a pragmatic method capable of implementing a cost-effective, low-dose CT reconstruction directly onto a dental panoramic X-ray imaging system by adopting a spiral source trajectory. In the proposed geometry, a linear-type panoramic imaging sensor is rotated 90° from the orientation for panoramic imaging to imitate fan-beam image acquisition. For image reconstruction, we considered a total variation (TV) minimization-based algorithm that exploited the sparsity of the image gradient and was capable of reconstructing CT images with substantially high image accuracy against the image artifacts from sparse-view data. We implemented the algorithm for the proposed geometry and performed systematic simulation works to demonstrate its feasibility for dental imaging applications. CT images were successfully reconstructed from the proposed geometry, and the reconstruction quality was evaluated quantitatively by using an image similarity metric. We expect the proposed method to be applicable to developing a cost-effective, low-dose, all-in-one dental imaging system.