OPTIMAL SCAN FOR TIME-VARYING TOMOGRAPHY .2. EFFICIENT DESIGN AND EXPERIMENTAL VALIDATION

In a previous paper, we presented a theoretical analysis of tomographi c reconstruction of objects with spatially localized temporal variatio n, such as a thorax cross section with a beating heart, That analysis showed that by using an optimally scrambled angular sampling order, th e scan rate required to avoid motion artifacts in the reconstructed im ages can be lowered as much as four times while preserving image quali ty, In this paper, we present a simple design procedure for the optimu m choice of angular sampling pattern, which depends only on pre-specif ied geometric and spectral parameters and the desired spatial resoluti on, The resulting patterns have a simple congruential structure, Recon struction is accomplished by interpolation to standard time-invariant scan format, followed by conventional reconstruction, The interpolatio n only requires linear shift-invariant separable filtering, at a negli gible computational cost, Simulation results demonstrate the technique and validate the analysis for both bandlimited and approximately band limited objects.