MR ANGIOGRAPHIC AND SONOGRAPHIC INDICATIONS FOR ENDARTERECTOMY

PURPOSE: Our objective was to determine whether appropriate criteria c ould be developed for performing an endarterectomy on the basis off so nographic and MR angiographic findings, METHODS: Fifty patients were e xamined prospectively with sonography, MR angiography, and conventiona l angiography. All three imaging studies were performed within 2 weeks of one another, and conventional angiography sewed as the reference s tandard. RESULTS: All 10 carotid occlusions were detected with sonogra phy and MR angiography. Sonography accurately showed flow in two arter ies, and MR angiography showed flow in one of three nearly occluded ar teries with extremely slow now, Multislab three-dimensional time-of-fl ight MR angiographic sequences underestimated the degree of stenosis i n 12 arteries, and in two cases this resulted from high T1 signal with in the atherosclerotic plaque, With conventional angiography as the re ference standard for 70% to 99% stenosis, sonography had a sensitivity of 96%, a specificity of 91%, and a positive predictive value of 90%, while concordant sonographic findings and the presence of a signal vo id on multislab 3-D time-of-flight sequences had a sensitivity of 72%, a specificity of 98%, and a positive predictive value of 97%, CONCLUS ION: Endarterectomy performed on the basis of sonographic findings of 70% to 99% stenosis and of a signal void on multislab 3-D time-of-flig ht MR angiographic sequences is appropriate.