A dual modality of cone beam CT and electrical impedance tomography for lung imaging

Electrical impedance tomography (EIT) is a new and emerging tomographic imaging system, which is able to provide high temporal resolution with low spatial resolution. In past few years, the EIT has been extensively studied for lung monitoring. Cone beam CT (CBCT) is an imaging system used in radiation therapy unit. The CBCT suffers from motion artefacts, making treatment planning inaccurate. This problem is very severe in lung cancer therapy. In this study a dual modality of EIT-CBCT has been proposed. Feasibility of such a dual system has been investigated using preliminary simulated phantom data. The motion information is extracted from the EIT images and has been used to compensate for the motion in CBCT through our recently developed iterative image reconstruction for CBCT. The results show that blurring artefacts around a tumour can be reduced for the motion compensated images using this dual modality combination. The dual EIT-CBCT imaging benefits from complementary high spatial resolution of CBCT and high temporal EIT resolution.