Selective intra-arterial dual-energy CT angiography (s-CTA) in lower extremity arterial occlusive disease

In patients with peripheral arterial occlusive disease, renal impairment is a common contraindication to iodine and gadolinium contrast media, which limits the utility of conventional computed tomography angiography (CTA) and magnetic resonance angiography (MRA). It is proposed that selective intra-arterial dual-energy CT-angiography (s-CTA), that is CTA with intra-arterial injection of an ultra-low dose iodine contrast media, is a feasible, safe and accurate alternative imaging method to conventional non-invasive contrast enhanced vascular imaging in this patient group. The aim of this study was to report a preliminary experience of s-CTA in patients with critical limb ischemia and renal insufficiency with respect to safety, feasibility, and diagnostic accuracy.

Ten non-consecutive patients with ischemic foot ulcers underwent s-CTA of one leg. Procedure related complications were recorded and imaging results were compared with conventional digital subtraction angiography (DSA).

A median 17 mL (range 10-19 mL) contrast media (400 mg I/mL) was used. The median baseline plasma creatinine was 163 μmol/L (range 105-569) pre s-CTA versus 153 μmol/L (range 105-562) post s-CTA (p = .24). There was no puncture site complication. Among the patients selected for intervention (n = 6 with 30 arterial segments) the s-CTA findings correlated well with the DSA findings; the diagnostic sensitivity was 100%, the specificity 89%, and the accuracy 93%.

In this pilot study, a novel imaging method (s-CTA) is presented that provides high-quality arterial phase images with ultra-low dose iodine contrast media useful also for patients unsuitable for conventional contrast enhanced imaging methods because of renal insufficiency.