The calculation of functional images was based on recorded fluoroscopic sequences. The Fourier coefficients of the first harmonic were calculated for each matrix element, and the amplitude and phase values were used for the generation of two synthetic images. The amplitude image demonstrated the maximum change in opacification with high image contrast. Phantom studies showed that a high correlation exists between the inverse phase differences and flow. The clinical application of the Fourier method revealed substantial additional information to conventional angiography in one of ten patients. While the morphological evaluation demonstrated no significant stenosis, the functional images showed a residual stenosis.