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
normalNormal saline flush anatomy. For example, in many people instead of two
anteriorAnterior cruciate ligament (acl) injury
Anterior knee pain
Anterior vaginal wall repair cerebral arteries, there are one. In some cases, arteries that are normally present as a fetus persist as an
extraExtra strength mylanta calci tabs
Extra strength pain relief artery. Sometimes it can be difficult to pick up on an MR
angiogramArteriogram
Cerebral angiography
Cholecystitis, cholangiogram
Coronary angiography
Gallstones, cholangiogram
Hemangioma - angiogram
Lymphangiogram
Percutaneous transhepatic cholangiogram
Renal arteriography.
Alternatively, a 'missing' artery could be one that is
blockedBlocked tear duct 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!