This paper presents a technique to estimate and model patient-specific pulsatility of cerebral aneurysms over one/ncardiac cycle, using 3D rotational X-ray angiography (3DRA) acquisitions. Aneurysm pulsation is modeled as a time varying/n-spline tensor field representing the deformation applied to a reference volume image, thus producing the instantaneous/nmorphology at each time point in the cardiac cycle. The estimated deformation is obtained by matching multiple simulated projections of the deforming volume to their corresponding original projections. A weighting scheme is introduced to account for the relevance of each original projection for the selected time point. The wide coverage of the projections, together with the weighting scheme, ensures motion consistency in all directions. The technique has been tested on digital and physical phantoms that are realistic and clinically relevant in terms of geometry, pulsation and imaging conditions. Results from digital phantom/nexperiments demonstrate that the proposed technique is able to recover subvoxel pulsation with an error lower than 10% of the maximum pulsation in most cases. The experiments with the physical phantom allowed demonstrating the feasibility of pulsation estimation as well as identifying different pulsation regions under clinical conditions.

This work was supported in part by Philips Healthcare, Best, The Netherlands, in part by/nthe CENIT-CDTEAM grant funded by the Spanish Ministry Of Science and Innovation (MICINN-CDTI), and partially generated in the framework of the/n@neurIST Integrated Project, which is co-financed by the European Commission (IST-027703).