Measurement of Carotid Stenosis Using Duplex Ultrasonography with a Microconvex Array Transducer: A Validation with Cerebral Angiography

BackgroundWe aimed to evaluate the validity of duplex ultrasonography (DUS) using a microconvex array transducer (MAT) with enhanced flow imaging (EFI) for visualization of the distal, internal carotid artery (ICA) and the accurate assessment of ICA stenosis.MethodsPatients who underwent both DUS and digital subtraction angiography (DSA) were registered for this study. DUS was performed by using a linear array transducer (LAT) and an MAT with EFI. The visibility of the ICA was compared between the 2 transducers. ICA stenosis was evaluated by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method on DUS, and the peak systolic flow velocity (PSV) was evaluated by using an MAT. These results were compared with DSA.ResultsIn 238 internal carotid arteries, the average length of visualized ICA was longer for DUS using an MAT than an LAT (38.7 ± 11.7 mm versus 25.8 ± 9.8 mm, P < .0001). In 68 stenotic, internal carotid arteries, the degree of ICA stenosis detected by the NASCET method on DUS was correlated to that on DSA (P < .0001, r = .969, and adjusted r2 = .938). PSV also correlated to NASCET method on DSA (P < .0001, r = .804, and adjusted r2 = .640).ConclusionsDUS using an MAT with EFI technology could reveal more extended distal views of the ICA and was strongly correlated with NASCET method on DSA.