Angiographic evaluation of restenosis at 6 months was performed using either 16 slice CTA or conventional intra-arterial DSA. CTAs were performed on a "Somatom Sensation 16" 16-row, multi-slice CT scanner (Siemens Medical Systems, Erlangen, Germany). The accuracy and specificity of multi-slice CT with automated reconstruction has been reported to be comparable to intra-arterial DSA17-20. All patients with a suspected restenosis (>50%) by CTA underwent a conventional DSA with confirmation of the diagnosis. We performed DSA rather than CTA as the initial imaging procedure in patients with a planned ipsilateral or contralateral (re)intervention at the 6-month follow-up visit.