Missed Diagnosis of Focal Subclavian Artery Stenosis Discovered During Duplex Ultrasound Examination

A 54-year-old woman with fibromuscular dysplasia presented with pain and discoloration of multiple fingers in her left upper extremity due to undiagnosed subclavian artery stenosis, which was presumed to be the source of distal embolization to the ulnar artery. After index computed tomographic angiography (CTA) and follow-up outpatient angiogram results were inconclusive, an arterial duplex examination was performed. A focal flow velocity increase and changes in arterial pulse Doppler waveforms identified a more proximal arterial stenosis that was missed on CTA and digital subtraction angiography.