Multi detector (64+) CT angiography of the lower limb in symptomatic peripheral arterial disease - preliminary assessment of accuracy and inter-observer agreement in an Australian tertiary care setting

Multidetector computed tomography angiography (CTA) is a reliable, widely available technology now commonly used in the initial evaluation of peripheral arterial disease (PAD). Meta-analyses comparing mainly 2-, 4-, and 16-detector multidetector CTA with the gold standard, digital subtraction angiography (DSA), have shown it to be highly accurate in patients with symptomatic lower extremity PAD [1,2]. CTA has a number of advantages over DSA including minimal invasiveness, shorter examination times, smaller volumes of contrast material used and a lower rate of complications. However, limitations of CTA include its susceptibility to 'blooming artifacts' when vessel wall calcifications are present, and potentially decreased accuracy in detecting and quantifying in-stent restenosis due to metallic or beam hardening artefact [3,4]. The purpose of this study was to evaluate the accuracy and inter-observer agreement of current generation (64+ detector) multidetector CTA for detection of haemodynamically significant stenosis in patients with symptomatic PAD in a tertiary care setting using digital subtraction angiography DSA as the reference standard.