Radial acquisition along with Polar Fourier Transform (PFT) reconstruction allows to retrospectively choose the image pixel-size. We experimentally investigated how this selected pixel-size was related to spatial resolution in fMRI studies. The functional contrast to noise ratio (CNR) was considered as a measure to assess whether the improvement in apparent spatial resolution is real or just resulted from interpolation. In an fMRI study on 9 subjects, SSFP raw data was reconstructed by PFT technique with four pixel areas. Results showed that the CNR improvement stopped at the boundaries of reduced-FOV, where the spacing in azimuthal and radial directions are equal.