A PROJECTION-BASED METHOD FOR MOTION-COMPENSATED NOISE SUPPRESSION

The diagnostic value of medical images significantly depends on the si gnal-to-noise ratio (SNR). Especially in fluoroscopic tomography, the SNR is limited by the radiation dose (Computer Tomography), or by the suitable acquisition techniques (Magnetic Resonance Imagine).The purpo se of this paper is to introduce a projection-based method for the mot ion-compensated SNR enhancement applied in Radon space. It is based on a projection-based motion estimation with subsequent motion-compensat ed, edge-preserving filtering of the measured projections. The effect of temporal filtering as well as spatial filtering will be presented. In contrast to the recently introduced image-based approach, this meth od allows a very efficient computational implementation, likely to be used in real time imaging. It will be shown that a significant increas e of the SNR can be achieved without introducing additional motion art ifacts or blurring in the reconstructed images. The proposed technique has the potential to be used for SNR enhancement in low-dose fluorosc opy applications in CT as well as for SNR improvements in MR fluorosco py using projection reconstruction based techniques.