In the LAO caudal/spider view, which feature is commonly evaluated?

• A. LAD and Cfx bifurcation
• B. Distal LM
• C. Origin of obtuse marginals
• D. Proximal LM

Answer: (A)

The spider view (LAO with caudal tilt) is particularly used to visualize the left coronary system in a way that separates the left main into its two primary branches. This projection makes the bifurcation of the left main into the left anterior descending (LAD) and the left circumflex (Cfx) arteries fall into a single plane with minimal overlap, so you can clearly assess the bifurcation point, the takeoff angles, and any plaque at that junction. That focus on the left main bifurcation is why LAD and Cfx bifurcation is the feature most commonly evaluated in this view. Other structures, like distal or proximal segments or origins of side branches, can be seen as well but aren’t the primary emphasis of this projection.