A preliminary study of an image synthesis method to simulate the change in the incident X-ray spectrum by using thickness information

The objective of this research is to suggest an image synthesis method to simulate the change in the incident X-ray spectrum, based on knowledge of the tissue thickness. The image of a reference phantom was acquired before acquiring the image of an object under the same condition. With knowledge of the thickness of an input pixel, the mapping region could be limited to a specific thickness region in the reference phantom. Taking advantage of the relation between the reference phantom and the imaging object mapped to a limited region, we could synthesize an image acquired at a different tube current and tube voltage. The noise difference was compensated for by the addition of zero-mean Gaussian noise, and RMSE(root mean-square error) between the synthesized image and the actual image was calculated. The average noise difference between the synthesized image and the actual image was about 4.5% (ranging from 0% to 7.7%). RMSE between those images was calculated to be about 1.4% of the average pixel intensity. The calculated results indicate that the proposed method can provide a synthesized image close to the actual image.