Ok, they don't think it's an aneurysm, but there is a definite bulge. CT scan on Tuesday to look closer.
There ya go. Ectasia (a widening, but less than an aneurysm), or maybe just a simple bulge (like your tummy ). Tests can yield true, or false information. All tests have their limitations, as do their interpretations. CT should yield definitive information in this setting.
By the way, have they discovered why your neck's red?