Where is the aneurysm in this picture? I'm a curious person, I've never had any medical training, but I wish to know some more about aneurysms. _Aneurysms_ are basically weakened spots in the elastic artery wall. This can eventually result in a blood-filled balloon bulging from the artery wall due to the high blood pressure in these vessels. Aneurysms can rupture and this can lead to brain damage when it occurs in the brain. Aneurysms can be detected by injecting contrast material into the bloodstream and making an X-ray (called an _angiogram_ ). Now I was reading a wikipedia article about **aneurysms** where I saw the following picture of an angiogram where reportedly an aneurysm should be visble: !aneurysm Now, as I said, I know nothing about biology so I would really appreciate it if someone could download the picture and reupload it with the aneurysm circled. Is it the really dark spot or the big soft spot to the right? Thanks!

Your image comes from the wiki page Aneurysm. The figure legend on the wiki page identifies it as:

> Angiography of an aneurysm in a cerebral artery

I am not an MD so I chose to first dig up a similar appearing cerebral angiography with the aneurysm identified (dark protruding spot indicated by the arrow):

!aneurysmSource: WestJEM, UC Irvine

Taking into account the normal vasculature as seen on this graph from UC Irvine, and given the similarity between the identified aneurysm in this angiopgraph and your wiki angiograph, I tentatively have identified the red-encircled structure in your original image as an aneurysm:

!wiki + identification