Figure 8b. Partial volume averaging effect. (a) Right anterior oblique catheter angiogram of the left coronary artery shows no stenosis. (b, c) MPR images depict no significant stenosis but do show a small calcification, which appears larger than it proved to be in reality. (d) Virtual endoscopic image of the coronary arteries reveals a calcified deposit at the LAD artery (arrow) without luminal stenosis.