IMAGING OF CAROTID-ARTERY STENOSIS - CLINICAL EFFICACY AND COST-EFFECTIVENESS

PURPOSE: To determine the most accurate, safe, and cost-effective imag ing protocol for selecting patients for carotid endarterectomy. METHOD S: The actual costs of carotid angiography, ultrasound, and MR angiogr aphy were calculated. The diagnostic accuracy with different confidenc e levels was assessed for carotid ultrasound and MR angiography in 45 patients. The cost-effectiveness and theoretical impact on patient out come of hypothetical screening models were compared. RESULTS: Ultrasou nd before angiography is more effective and considerably cheaper than performing angiography in all patients presenting with transient ische mic attacks ($25 216 versus $48 708 imaging costs per one prevented st roke). When the more costly MR angiography was used to select patients for angiography the slightly higher diagnostic accuracy did not resul t in a greater number of prevented strokes. As the only preoperative s crutiny, the combination of ultrasound and MR angiography would have r esulted in a greater number of prevented strokes than invasive angiogr aphy (27.9 Versus 23.3) but at the expense of unnecessary surgery (6.6 % of all surgeries). CONCLUSIONS: Ultrasound followed by confirmatory angiography is a cost-effective way to image patients suspected of car otid artery stenosis. MR angiography may become cost effective and lea d to a better final patient outcome only when it can reliably replace invasive angiography as the preoperative examination.