Figure 4. Preablation baseline contrast-enhanced multisection CT scan (four sections, 2-mm collimation, 1-mm reconstruction interval) obtained in a 60-year-old woman shows the confluence of the left PVs. Volume-rendered posterior view shows a single ostium on the left side (*) and three distinct ostia on the right. LI = left inferior, LS = left superior, RI = right inferior, RM = right middle, RS = right superior.