FIGURE 4.

(a) In the presence of motion, Cartesian sampling generates ghosting artifacts, while radial sampling generates blurring. When imaging is performed in the axial plane, radial sampling is more robust to motion. (b) Radial sampling has higher incoherent undersampling behavior compared to Cartesian sampling. Undersampling a 2D Cartesian trajectory is typically performed along the phase‐encoding dimension only, and this leads to aliasing artifacts that spread along the phase encoding dimension. Undersampling a radial trajectory effectively enable acceleration along two spatial dimensions, which generates artifacts that spread along varying directions.