4D CT or time-resolved CT images dynamic processes in full 3D, where "time" is considered the 4th dimension. These processes can be imaged in steps, with no movement during a scan and in this case we speak of "time-lapse imaging". When processes happen fast, so-called "real-time imaging" is applied. This requires fast, continuous scanning of the sample, a task for which the SkyScan 1275 is an ideal system. The development of micro-CT technology made these 4D imaging methods possible in laboratory machines, and is now finding its way in the geoscience community where movement of fluids and crystallization of solids in pore spaces are the driving forces in e.g. oil and gas recovery or weathering of natural stone.
Time lapse CT of these processes is performed by scanning a slow process at intermediary steps, e.g. every day or after each cycle of a certain treatment. In time-lapse CT, image quality is often more important than acquisition speed, so this can be done on mostmicro-CT systems.
Real-time imaging of dynamic processes requires short acquisition times, as samples are not stable during a scan. Making the scan time as short as possible minimizes the movement of the sample and the phases inside it during acquisition, reducing movement artefacts during reconstruction. Real-time imaging focusses mostly on imaging speed and less on image quality. The SkyScan 1275 can perform scans in 1 - 3 minutes, while keeping enough image quality for quantitative analysis of processes.
