This paper discusses first results of bubbles moving through a fluidized bed imaged with an X-ray Tomographic Scanner. The scanner is made of 3 medical X-ray sources equipped with 30 CdWO4 detectors each. The fluidized bed has a diameter of 23 cm and is filled with Geldart B powder. The scanner measures the attenuation in a thin slice perpendicular to the column axis at a sampling frequency of 2500 Hz. The data collected during 2 s are reconstructed using the SART algorithm with a one-step-late correction. The reconstructions show the distribution of the bubbles in the 2-dimensional cross-section. By stacking these images. a 3-dimensional view of the bubbles in the column is represented. (c) 2009 Elsevier B.V. All rights reserved.