Currently, only self-gated or ultra-fast sequences allow an adequate temporal resolution to resolve different cardiac phases during lung perfusion. First studies show the benefit of this additional information. Nevertheless such techniques are not widely available. Therefore, in this study a post processing method is assessed, which can increase the temporal resolution by sorting images according to their cardiac phase using a piecewise cosine fit. The feasibility is demonstrated in 6 healthy volunteers and two patients with chronic thromboembolic hypertension (CTEPH). The easy implementation and possibility of retrospective evaluation of existing Fourier Decomposition acquisitions are the advantages of this method.