Evaluation of intracranial and extracranial carotid steno-occlusive diseases in Taiwan Chinese patients with MR angiography: preliminary experience.

BACKGROUND AND
PURPOSE: We attempted to evaluate the location of vascular lesions in cases of cerebrovascular steno-occlusive diseases in Chinese persons living in Taiwan.
METHODS: With three-dimensional time-of-flight magnetic resonance angiography (MRA) as a screening tool, 108 symptomatic patients with cerebrovascular steno-occlusive diseases were examined. Cardioembolic disease and cerebral hemorrhage cases were excluded. The degrees of stenosis of bilateral cervical carotid arteries and their major intracranial tributaries were recorded. They were categorized as nonsignificant stenosis (0% to 49%), significant stenosis (50% to 99%), and total occlusion.
RESULTS: Our data revealed that 32.4% of the cases were normal in either cervical carotid arteries or their intracranial tributaries. In 24.1% of the cases, significant extracranial carotid stenosis or occlusion was the only finding on MRA. In 25.9% of the cases, only significant intracranial-tributary stenosis was found. In 17.6% of them, significant lesions were found in both extracranial and intracranial carotid artery tributaries.
CONCLUSIONS: A racial difference between Chinese and white patients in location of lesion in cerebrovascular steno-occlusive diseases was confirmed. About one third of symptomatic Chinese patients living in Taiwan showed small-vessel disease. Approximately 24% of patients had only extracranial carotid disease, and about 26% had only intracranial carotid tributary disease. We need a larger series of patients to confirm these findings. However, MRA might be a good screening tool for steno-occlusive cerebrovascular disease, especially in persons of a race with more intracranial carotid disease, such as the Chinese.