Objective: To prove the feasibility of 3D reconstructions of the diaphragm during respiratory cycle, using EPI sequences. Materials and Methods: EPI acquisition, 270 ms/image, on a healthy subject breathing spontaneously and at 0.1Hz. Continuously recorded respiratory signal allowed for retrospective synchronization with respiratory phases for reconstruction of successive diaphragm surfaces using a specifically designed software. Displacements, area and volume changes of the diaphragm were quantified. Results: Our measurements were comparable with literature data. Reconstructed surfaces allowed in vivo diaphragm dynamics evaluation, in terms of displacements, area and volume variations. Conclusion: EPI has adequate spatial and temporal resolution for studying diaphragm dynamics during natural breathing.