The technique using changing masks for visualizing changes in contrast media is Time interval difference imaging, distinguishing it from other fluoroscopy methods.
The digital fluoroscopic imaging technique that utilizes changing masks to provide information on changes in contrast media content within a structure is called Time interval difference imaging. This technique is particularly useful in visualizing dynamic processes within the body, such as blood flow or the function of organs, by comparing images taken at different times.
It contrasts with other imaging techniques, like mask mode fluoroscopy, where a static image is used as a reference; K-edge fluoroscopy, which is based on the energy-dependent absorption of X-rays; and synchronized fluoroscopy, which coordinates image acquisition with a particular phase of patient motion or a physiological process.