A Shift‐Variant Deconvolution for Aperture Correction of Collimator in Emission CT—Experimental Verification

One of the causes of the image‐quality degradation in emission computed‐tomography (ECT) is the characteristic of the aperture of its detection system. This is due to the geometrical structure of the collimator used for limiting the direction of the emitting ray. This kind of degrading causes a shift‐variant blurring in its reconstructed image. We have proposed a method of compensating the degradation by expanding the measured projection data into their frequency space so that the effect of the aperture is turned into a shift‐invariant blurring in each frequency [4, 5], This paper describes an application of the correction method to actual data obtained by light‐emission CT using visible light. The result confirms the usefulness of the proposed method.