While the two procedures are similar in helping arterial and vessel blockages, they are different in what they do. An angiogram is finding the source of the problem, and an angioplasty is repairing and restoring the problem. Summary. 1. Angiograms are the medical recording and analysis of a potential blood vessel which is not working properly. Angioplasty is the process of unblocking a clogged or blocked blood vessel or artery. 2.