Leptomeningeal Collaterals Strongly Correlate with Reduced Cerebrovascular Reactivity Measured by Acetazolamide-challenged Single-photon Emission Computed Tomography Using a Stereotactic Extraction Estimation Analysis in Patients with Unilateral Internal Carotid Artery Stenosis

Objective To assess the correlation between the angiographic appearance of cerebral collateral pathways or the degree of internal carotid artery stenosis (ICAS) and reduced cerebrovascular reactivity (CVR) estimated by single-photon emission computed tomography (SPECT) image analysis in patients with unilateral ICAS. Methods A retrospective analysis was performed in 42 patients with unilateral ICAS who underwent cerebral angiography and acetazolamide-challenged SPECT of the brain. Cerebral blood flow quantitation was performed using the quantitative SPECT/dual-table autoradiography method. The CVR in the middle cerebral artery (MCA) territory was evaluated using the stereotactic extraction estimation based on the Japanese extracranial-intracranial bypass trial (SEE-JET) program and classified as reduced (