Comparison of intra-arterial digital subtrction angiography, magnetic resonance angiography and duplex ultrasonography for measuring carotid artery stenosis. - Modaresi,K.B.; Cox,T.CS.; Summers,P.E.; Jarosz,J.M.; Verma,H.; Taylor,P.R.; Padayachhe,T.S. (Br J Surg, 1999)