Techniques to alleviate the effects of view aliasing artifacts in computed tomography

Abstract

Due to practical limitations in data acquisition, 3-D computed tomography systems must attempt to provide rapid reconstructions of acceptable quality from a limited number of views. The use of convolution backprojection (CBP) for image reconstruction from an inadequate number of projections, results in view aliasing artifacts. In this paper we investigate different post-processing methods of alleviating the effects of view aliasing artifacts. Two distinct methods and their variants are considered. The first, termed the intermediate view reprojection (IVR) method, involves estimating a set of intermediate views by reprojection, followed by a reconstruction using the augmented set of views. The second, termed the error-correction (EC) method, incorporates a correction on the initial reconstruction based on the projection-domain error. Suitable modifications and variants of the above methods are indicated. Of the methods discussed, the IVR method is simple, tends to reduce the effects of artifacts with less susceptibility to secondary effects, and is applicable to region-of-interest reconstructions.

3D soft tissue imaging with a mobile C-arm

“…Artificial interpolated images between adjacent projection images reduce the resulting streaks [13].…”

A Method for Sinogram Interpolation for Reducing X-ray Dose

“…이 경우 영 상 재구성을 위한 충분한 view가 확보되지 않기 때 문에 방사형 직선형태의 왜곡이 발생한다 [1] . 이를 Reprojecrion : IVR) [5] . Goshtasby등이 제안한 논문 [6] 에서는 연속된 슬라이 스를 보간하여 물체의 체적 데이터를 얻는 이용하 였으나 본 논문에서는 sinogram에 적용하여 각 픽 셀간의 매칭을 수행하는데 적용하였다.…”

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“…A Feldkamp-type algorithm was customized to deal with the special acquisition geometry of RA in a very fast and flexible way [7], [8]. In addition, the algorithm may take advantage of the relative long distance between the C-arm isocenter and the focal spot of the X-ray tube to speed up the whole computation [9].…”