QUANTIFICATION OF EXTRACRANIAL STENOSES O F THE CAROTID-ARTERY - MR-ANGIOGRAPHY AND DOPPLER SONOGRAPHY VS INTRAARTERIAL ANGIOGRAPHY

To assess various non-invasive techniques for quantifying internal car otid artery CA stenosis, per cent luminal diameter reduction on intraa rterial angiograms (IAA) was measured in 63 patients with ICA stenosis or occlusion. These data were compared with independent measurements based on MR-angiography, continuous-wave (cw) Doppler ultrasonography, systolic peak flow velocity and colour Doppler assisted duplex imagin g. Correlations with IAA were equally strong for MR angiography, cw Do ppler and colour Doppler analysis (0.95; 0.92; 0.92). Positive predict ive values for > = 70% ICA stenosis were lower and negative predictive values were higher for cw Doppler (0.85; 0.92) and colour duplex anal ysis (0.81; 0.94) than for MR angiography (0.86; 0.88). Statistical an alysis showed non-linear correlations between percentage of lumen diam eter narrowing and the length of the zone of signal intensity loss (0. 72) and maximum systolic peak flow velocity (0.77). Conclusion: Severa l non-invasive methods do compare with IAA in identifying and quantify ing high-grade ICA stenosis and may suffice for decisions on treatment .