COMPARISON OF MAGNETIC-RESONANCE VOLUME FLOW-RATES, ANGIOGRAPHY, AND CAROTID DOPPLERS - PRELIMINARY-RESULTS

Background and Purpose We compared the results of conventional angiogr aphy, carotid Doppler, and magnetic resonance angiography volume flow rates to determine the clinical utility of volume flow rate assessment of blood flow to the anterior circulation in patients with carotid oc clusive disease. Methods From 11 symptomatic patients, a total of 22 e xtracranial carotid arteries were studied with all three techniques. T he studies were independently read, and regression analysis was used t o compare the measurements. Results Carotid Doppler measurements of th e distal extracranial carotid arteries were proportional to the invers e of the extracranial carotid volume flow rate (r=.53, R(2)=29%, P<.01 ), volume flow rates were proportional to the inverse of measured perc ent stenosis on angiography (r=.84, R(2)=71%, P<.01), and Dopplers wer e proportional to angiography (r=.94, R(2)=90%, P<.01). Symptomatic Do ppler systolic velocity was significantly higher (P<.002), symptomatic measured stenosis was significantly higher (P<.002), and symptomatic volume flow rate was significantly lower (P<.01) than their respective asymptomatic-side values. These preliminary observations, however, ma y well change once a large data set, especially one in which more pati ents with high-grade carotid stenosis are included, is studied. Conclu sions Assessment of carotid volume flow rates by magnetic resonance an giography quantifies flow reduction secondary to atherosclerotic occlu sive disease. The easily obtained flow data add both documentation of arterial flow characteristics related to internal carotid stenosis and information regarding the adequacy of collateral pathways.