Figure 5a. Left main coronary artery. (a) Axial CT image shows origin of the left main coronary artery (arrow) from the aorta. (b-d) Axial oblique (b) and coronal oblique (c, d) volume-rendered images show bifurcation of the left main coronary artery (black arrow). The LAD artery and diagonal branches (white arrows) and the LCX artery (arrowhead) are also seen. High-attenuation areas in the vessels represent calcifications.