Evaluation of image lag in a flat‐panel, detector‐equipped cardiovascular X‐ray machine using a newly developed dynamic phantom

We developed a dynamic phantom for use in routine checks. This phantom can be used to physically evaluate image lag that occurs in dynamic images. It has a unique measurement method. ROIs on the target are chosen, and, with the position of ROIs fixed on the image, changes in pixel value are detected physically when the target passes through the ROIs over time and perceived as image lag. Thus, it was possible to physically detect different intensities of image lag lasting less than one second while maintaining the same intensity trends. The checking technique we propose with the dynamic phantom that we developed could be effective for routine checking of fluoroscopy X‐ray machines, and could become an established method. PACS number: 87.59.C‐, 87.59.Dj