Which artery is characteristically associated with a high-resistance waveform?

Which artery is characteristically associated with a high-resistance waveform?

• A. ECA
• B. ICA
• C. Vertebral artery
• D. CCA

Answer: (A)

High-resistance waveforms appear when the downstream vascular beds have higher impedance, producing a sharp, prominent systolic peak with little diastolic flow. The external carotid artery fits this pattern because it supplies the face and scalp, where the downstream vascular beds present higher resistance. That makes its Doppler signal tend to be high-resistance. In contrast, the internal carotid artery feeds the brain, a low-resistance circuit, so its waveform shows substantial diastolic flow and a more continuous profile. The vertebral artery and other cerebral feeders similarly display low-resistance patterns due to their downstream demand for steady brain perfusion. The external carotid artery’s characteristic high-resistance waveform is the hallmark you’d expect to see in this context.

High-resistance waveforms appear when the downstream vascular beds have higher impedance, producing a sharp, prominent systolic peak with little diastolic flow. The external carotid artery fits this pattern because it supplies the face and scalp, where the downstream vascular beds present higher resistance. That makes its Doppler signal tend to be high-resistance. In contrast, the internal carotid artery feeds the brain, a low-resistance circuit, so its waveform shows substantial diastolic flow and a more continuous profile. The vertebral artery and other cerebral feeders similarly display low-resistance patterns due to their downstream demand for steady brain perfusion. The external carotid artery’s characteristic high-resistance waveform is the hallmark you’d expect to see in this context.