Spatio-temporal Constrained Adaptive Sinogram Restoration for Low-dose Dynamic Cerebral Perfusion CT Imaging

Dynamic cerebral perfusion computed tomography (PCT) imaging shows its potential in acute stroke diagnosis by visualizing and quantifying hemodynamic information of cerebral tissue and vessels. However, high radiation dose imposed on patients during dynamic PCT scanning has aroused growing concerns. To address this issue, we proposed a spatio-temporal constrained adaptive sinogram restoration (ST-ASR) method to improve the quality of dynamic cerebral perfusion CT imaging with low-dose protocol. The proposed ST-ASR method explores the spatio-temporal correlation in dynamic cerebral PCT projections to develop a new spatio-temporal prior model for sinogram restoration, and conducts an adaptive sinogram weighting according to the noise variance of sinogram data. Experimental results with clinical patient data demonstrate that the proposed ST-ASR method can achieve noticeable improvements over existing adaptive sinogram restoration method in terms of noise reduction and quantitative evaluations for low-dose dynamic cerebral PCT imaging.