Time-resolved computed tomography or 4D-CT

3D CT allows any objects to be captured, including all external and internal structures, completely, contract-free, and in a non-destructive manner. The static 3D CT data record of the test object generated here has been expanded with information about time and motion by means of processes developed at Fraunhofer EZRT. This allows dynamic processes inside objects to be visualized and analyzed.

Principle of time-resolved computer tomography

Classic 2D or 3D computer tomography (CT) provides information about the geometries of structures hidden inside the test object when it is in a static condition. If the test object is subjected to a dynamic change, however, such as motion due to physical or chemical processes, measurements need to be taken of all conditions that are relevant for the acquisition of knowledge. To this end, the recording speed must be faster than the speed of the process being observed. In conventional CT, this is only occasionally the case.

Time-resolved computer tomography, or 4D CT for short, allows us to record, analyze, and visualize the effects of time and other physical factors.

System description

Fraunhofer EZRT is developing different recording and reconstruction procedures for processes that change over time.

There are different recording concepts: On the one hand, there is the classic CT sampling method, where the object is turned 360 degrees during the recording. On the other hand, there are also non-tamper method such as tomosynthesis for layered mapping of flat objects or the gantry variant where the imaging system rotates around the object. This recording process does not involve any influencing of the process by the CT, allowing observation of motion-sensitive processes to take place in situ.

Fields of application

  • Analysis of interaction of components subject to extreme outside influences such as load tests in quality control.
  • Creation and disintegration processes of foams (e.g. protein foams in food production)
  • Material transport processes in chemical reactor vessels at temperatures of over 2000 degrees Celsius
  • Flow kinematics in granulate in chemistry and biology

Advantages and customer value

  • New insight into developement of process over time
  • Non-contact measurements
  • Measurement of motion-sensitive processes in situ