[Evaluation of cerebro-vascular diseases with persistent carotid-basilar anastomosis].

Five cases of cerebro-vascular diseases with carotid-basilar anastomosis were evaluated. Case 1: a 73-year-old female was diagnosed as having subarachnoid hemorrhage due to a ruptured aneurysm of the right internal carotid artery-posterior communicating artery bifurcation and demonstrated that a left proatlantal intersegmental artery. Case 2: a 38-year-old female showed intraventricle hemorrhage due to arteriovenous malformation and showed left primitive hypoglossal artery. Case 3: 73-year-old female was diagnosed as having subarachnoid hemorrhage due to a ruptured basilar top aneurysm and demonstrated that a right primitive hypoglossal artery. Case 4: a 29-year-old male with unruptured aneurysm of the left internal carotid artery-posterior communicating artery bifurcation, and right trigeminal artery was detected incidentally by magnetic resonance angiography (MRA). Furthermore, right proatlantal intersegmental artery was detected by conventional angiography. Case 5: a 76-year-old male was diagnosed as having subarachnoid hemorrhage due to a ruptured aneurysm of the anterior communicating artery. MRA showed the aneurysm and a primitive trigeminal artery. No clinical symptom related with carotid-basilar anastomosis was detected. Magnetic resonance angiography (MRA) was useful for diagnosis of asymptomatic carotid-basilar anastomosis. Especially, axial view of MRA by time of flight method detected two cases of a primitive trigeminal artery. And coronal view of MRA by phase contrast method is useful for diagnosis of primitive proatlantal intersegmental artery. More asymptomatic persistent carotid-basilar anastomosis may be detected by MRA.