Figure 1

The beginning of the PFT procedure is shown on the k-space of the first cardiac frame. After performing the first 1D-FFT of the radial tagged images, the tagging energy is concentrated in two highlighted lines, which are the reminiscent of spectral peaks in the 1-1 SPAMM. Inspired by HARP, only few Fourier-coefficients around one of the highlighted lines can be isolated to form a 2D complex image of the tagging fundamental frequency. This was repeated for the conjugate highlighted line and therefore, the conjugate harmonic phase was reconstructed. Based on the peak-combination HARP, the two images were subtracted to improve the accuracy of the resulting phase map. The harmonic phase images were then unwrapped and used for calculation of the displacement field.