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Paper No. 14-25

Download 14-25

A Kueh, WS Kendall & TE Nichols

Modelling the Penumbra in Computed Tomography

Abstract: The aim of this paper is to quantify the blurring in the image which is caused by the X-ray source not being a point source. We do this by studying the penumbra, which is the blurring specifically at the edges of the object image. If the source were a point, there would be sharp
discontinuity at the boundary of the image. However, the data shows that this boundary instead exhibits almost linear decay, indicating that the source is not sharp. Indeed, the steepness of the slope should give an insight into the spot geometry, which is the area from which the X-rays
originate.