Figure 3a. Pulsation artifacts. (a, b) Left anterior oblique (a) and anterior (b) MPR images clearly demonstrate a kymographic gap along the RCA with moderate motion artifacts at the mid-RCA. (c) Left anterior oblique thin-slab maximum-intensity-projection (MIP) image is suspicious for mild stenosis at the mid-RCA (arrow). (d) Anterior thin-slab MIP image shows definite motion artifacts (arrows), which appear to create pseudostenosis at the mid-RCA. In theory, MIP obscures a kymographic gap perpendicular to the slab plane, since the appearances of thin-slab MIP images depend on slab thickness and the orientation of the vessel of interest relative to the slab plane.