MAGNETIC-RESONANCE ANGIOGRAPHY AND DUPLEX IMAGING - NONINVASIVE TESTSFOR SELECTING SYMPTOMATIC CAROTID ENDARTERECTOMY CANDIDATES

Background. This report describes our experience with the use of duple x imaging and magnetic resonance angiography (MRA) in the diagnosis an d management of 70 patients with symptomatic carotid artery disease. P rospective evaluation of our first 30 patients showed that duplex imag ing and MRA accurately correlated with conventional cerebral arteriogr ams (XRA) in patients with symptoms with greater than 70% ipsilateral carotid artery stenoses. In MRA versus XRA accuracy was 94%, sensitivi ty 100%, and specificity 93%. With duplex scanning versus XRA accuracy was 88%, sensitivity 93%, and specificity 93%. Methods. We are now pe rforming carotid endarterectomy on patients with symptoms without preo perative XRA when there is exact correlation between duplex imaging an d MRA. Patients must have focal hemispheric symptoms, ipsilateral dupl ex peak systolic velocity greater than 2 m/sec, and high-quality MRA i maging of the carotid vessels. Results. We have prospectively entered 40 patients for preoperative evaluation with duplex imaging and MRA. H igh-quality MRA and duplex studies were obtained in 35 patients (88%). XRA was required in the remaining five patients (12%) because of disc repancies between duplex scanning and MRA. Endarterectomy was performe d without morbidity or death. Combined use of duplex scanning and MRA eliminated XRA in 35 cases and created a net savings of more than $125 ,000. Conclusions. Our experience suggests that preoperative XRA may n ot be necessary when duplex imaging and MRA confirm the presence of se vere extracranial disease.