CFD is a valuable tool for understanding the flow and pressure drop in packed beds. However, determining the geometry can be complex. One possible method is to use a non-invasive imaging method such as MRI, however, problems occur in processing complex geometries when using traditional commercial meshing software. This work focuses on the use of image based meshing software originally developed for the field of computational biomechanics, to create geometries from 3d MRI scans of packed beds for use with computational dynamics. For this work we focus on disordered packed beds of cylinders at low aspect ratios and Reynolds numbers of Re = 1431-5074 (based on particle diameter and superficial velocity). We compare CFD studies with experimental data performed on the actual scanned beds and compare these with the correlation proposed by Eisfeld and Schnitzlein (2001). Computational data is shown to correlate well with experimental and theoretical results. (C) 2011 Elsevier Ltd. All rights reserved.