This study presents the 3D characterization of the nodal region of an Arundinaria amabilis bamboo using X-ray micro-computed tomography imaging (µCT). The complex pattern of vascular bundles across the node was identified, and the sample was characterized regarding the relative volumes of parenchyma and sclerenchyma tissues. The results show that the node witnesses the development of radial and tangential vascular bundles, forming a net-like pattern. Some specific nodal structures ("splitting bundles") were also identified: regularly distributed around the culm, they split below the diaphragm between bundles crossing radially into the diaphragm and others deviating to the outer side of the culm. Finally, the volumetric fraction of lignified sclerenchyma tissue reaches a minimum at the location of the node. In addition, the µCT technique was used to build a discretized model of an internodal part of the bamboo sample, thus allowing to recreate the real 3D structure of the composite material and showcasing the potential of µCT imaging for finite element analysis.