Development of a CCD-based optical computed tomography scanner used in 3D gel dosimetry

This study proposed a CCD-based (charge-coupled device) optical computed tomography scanner (CT-s2) for 3D gel dosimetry. A parallel laser light was generated to pass through the gel sample using a diffuser and collimating lens. A CCD was used to capture projection image of gel sample at each step. An image reconstruction algorithm, filtered-back projection (FBP) technique was used to reconstruct the 3D image. Two better rotational steps are suggested as 1.0 degree and 1.5 degree for considering both of angular resolution and position deviation. The un-irradiated and irradiated BANG gel samples were scanned and reconstructed using FBP technique. Some artifacts were found in reconstructed images. Some discussions for artifacts were conducted and some solutions provided by previous researches to reduce these artifacts will be evaluated in the future work.