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Angular weighted hybrid cone-beam CT reconstruction for circular trajectories.

M Grass·T Köhler·R Proksa
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Abstract

Hybrid reconstruction techniques have been introduced for the volume reconstruction of axially truncated cone-beam computed tomography projection data acquired along a circular source-detector trajectory. The introduction of weighted half-scan techniques into this framework is described in this paper. Due to the cone-beam geometry it is not possible to perform the weighting on the projections as is typically done in conventional single-line computed tomography. Hence, in this paper we present an efficient way to incorporate angular weighting functions, depending on the object point position, into the framework of hybrid cone-beam reconstruction. Four different angular weighting functions are introduced and discussed with respect to their cone-beam artefact behaviour and their influence on the signal-to-noise ratio. As a result, the most effective angular weighting function for hybrid circular cone-beam reconstruction is determined by means of a simulation study based on mathematical phantoms and clinical data sets. This distance-weighted angular weighting scheme yields the best results in terms of high image quality, low computational complexity and signal-to-noise variations in the reconstruction volume.

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Computer SimulationHumansImage Processing, Computer-AssistedModels, StatisticalModels, TheoreticalPhantoms, ImagingTomography, X-Ray ComputedJournal Article

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BibTeXRIS

M Grass, T Köhler, R Proksa. 2001. Angular weighted hybrid cone-beam CT reconstruction for circular trajectories.. https://doi.org/10.1088/0031-9155%2F46%2F6%2F301

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