Its difficult for me to comment on your question without knowing more specific information
Many people have 'missing' vessels on their brain as a variation of the normal anatomy. For example, in many people instead of two anterior cerebral arteries, there are one. In some cases, arteries that are normally present as a fetus persist as an extra artery. Sometimes it can be difficult to pick up on an MR angiogram.
Alternatively, a 'missing' artery could be one that is blocked off, such as in a stroke or a congenital blockage from birth like Moya-Moya disease. This should be apparent on the MRI scan and the clinical situation - I do not have this information so cannot be more specific in your case, sorry!
hello i am not sure if it said which 1 was missing all i know is they told me that there was 1 missing, they told me that there is 1 that is expanding and putting presure on the stroke sensor(whay ever that is).
You have to get the mri report and read it again. You can't have the circle of Willis missing...all the main arteries connect to the circle of Willis. Maybe you have a vertebral artery missing? Get the report out and read it again...if you don't have a copy of the report you can call the MRI place where you had it done and they can fax or send you a copy and you can also request it on a CD disc and view it on your computer or hand it to your neurologist to look over it.
Did it say which vessel is missing?
it is a vessle that is missing.