Quantitative flow ratio for the functional assessment of extracranial internal carotid artery stenosis

In asymptomatic patients presenting with significant internal carotid artery (ICA) stenoses undergoing endovascular revascularization, a selective angiography before stenting (CAS) is required. Sometimes, angiographic findings could be discordant from non-invasive assessment and a tool able to evaluate functional relevance of the stenosis could be of value. We sought to evaluate the usefulness of quantitative flow ratio (QFR) as angiography-based tool for functional assessment of ICA stenoses.