The pitfalls of duplex scanning in bilateral distal stenosis of the internal carotid artery

The duplex scan is the main tool used to diagnose carotid artery stenosis, and there is agreement that it might be the single preoperative diagnostic test. All limitations of carotid duplex scanning should be taken into consideration during qualification to surgical or endovascular treatment. Awareness of these limitations is especially important when neurological symptoms are typical and duplex examination is negative. The authors describe the pitfalls of the duplex scan examination in a symptomatic patient with bilateral severe distal internal carotid artery stenosis.