Lorentz Workshop “Quantitative 3D X-Ray Imaging: from Tomographic Images to Metrics”, Jan. 11-15 2016, Lorentz@Oort.


Modern X-ray tomography techniques, combining a mixture of advanced experimental imaging and novel mathematical reconstruction methods, are a topic of intensive study where many advances are currently made. After obtaining the 3D images, the next step forward in addressing scientific questions is constituted by the determination of quantitative parameters describing the phenomenon under investigation. The main goal of this workshop was to initiate a thorough discussion about the extraction of quantitative object features based on 3D X-ray imaging.


The workshop brought together around 50 participants from different communities (computational, engineering, experimental, metrology, biomedical, materials science) involved in X-ray tomography both with synchrotron and conventional sources. For the discussions, three groups were initially formed around the three key topics of

1.       Dimensional metrology

2.       Quantification of dynamic processes

3.       Quantitative X-ray orientation imaging

The discussions in each of the groups developed in very different way. The approach of dimensional metrology aims to define guaranteed system properties for quantitative imaging, such that the full imaging pipeline must be taken into account. As this topic was relatively new to many of the mathematical and experimental imaging participants, much of the discussion focused on becoming familiar with the basic metrological and statistical concepts. The dynamic processes discussion group followed a more hands-on approach, focusing the discussion on how to define useful 4D (3D plus time) phantom objects that can be used for validating reconstruction algorithms and on the challenge of visualization in dynamic tomography. Finally, the X-ray orientation imaging group was relatively small, discussing mainly opportunities to join software efforts in order to benefit as a community from each other’s work.


The workshop featured a substantial number of excellent, high profile speakers who gave a broad series of lectures about all the concepts involved in quantitative tomography. During the workshop, we gradually started to realize that the problems of carrying out quantitative time-resolved X-ray imaging requires a very high degree of standardization, which is difficult to achieve in practice. The key positive result of this workshop is the awareness that has risen in the community of the difficult steps that have to be taken to achieve this goal. As a concrete step, a new software project was started during the workshop to develop an open-source implementation of a 4D phantom object that can be used for standardized, configurable simulations.


Overall, the workshop was received in a very positive way. We expect that in the coming year, several publications will emerge from the collaborations initiated at this Lorentz Workshop. This workshop was partially funded by the EU EXTREMA COST Action, a network grant for advanced tomography.