Agreement of duplex ultrasonography vs. computed tomography angiography for evaluation of native and in-stent SFA re-stenosis—Findings from a randomized controlled trial

Abstract Background Multidetector CT angiography (CTA) is a non-invasive imaging technique for evaluation of peripheral vascular disease. CTA might be particularly useful for assessment of intermediate- and long-term morphological outcome after endovascular treatment. Validation of CTA vs. the current imaging standard, colour Doppler ultrasonography (CDUS), for quantification of native and in-stent re-stenosis in the superficial femoral artery (SFA) is required. Methods Seventy randomized patients who underwent stent implantation ( n = 47) or balloon angioplasty ( n = 23) underwent 6-month follow-up with CDUS and CTA. CTA was compared with CDUS in both sub-groups of patients in terms of binary re-stenosis (>50% lumen narrowing) and re-occlusion. Agreement between CTA and CDUS was assessed using Kappa ( κ ) statistics with 95% confidence intervals, and correlation coefficients. Results Binary re-stenosis was detected in 16/70 (22.9%) patients by CTA and 17/70 (24.3%) patients by CDUS ( κ = 0.88, 95% CI: 0.80–0.96). Re-stenosis rates after balloon angioplasty were 39.1% (9/23) on CTA and CDUS ( κ = 0.82, 95% CI: 0.66–0.98), and after stent implantation 14.9% (7/47) on CTA and 17.0% (8/47) on CDUS ( κ = 0.92, 95% CI: 0.84–1.00). Re-occlusions were detected in 3/70 (4.3%) patients by both CTA and CDUS ( κ = 0.65; 95% CI 0.54–0.76). Significant correlations ( r = 0.85, p < 0.001) were noted between degree of re-stenosis on CTA and peak velocity ratio on CDUS. The correlation coefficient was higher in patients after balloon angioplasty ( r = 0.94, p < 0.001) than in patients after stent implantation ( r = 0.71, p < 0.001). Conclusion CTA and CDUS show excellent agreement for evaluation of native and in-stent re-stenosis after endovascular treatment of SFA obstructions. CTA is an appropriate non-invasive imaging modality for follow-up after endovascular therapy.