Carotid and Vertebral Duplex Report Template: Measurements and Examples

Carotid and vertebral duplex report framework

A useful report links grayscale plaque and lumen appearance with spectral Doppler findings. Record the highest internal carotid artery (ICA) peak systolic velocity (PSV), the associated end-diastolic velocity (EDV), the common carotid artery (CCA) PSV used in the ratio, and the resulting ICA/CCA PSV ratio for each side. State the criteria used to assign a stenosis category. Do not transfer ultrasound velocity thresholds to CTA/MRA stenosis measurements.

Indication: [Stroke/TIA, bruit, surveillance, or other clinical question]
Comparison: [Date and examination, if available]
Technique: Bilateral extracranial carotid and vertebral artery duplex ultrasound using grayscale, color Doppler, and spectral Doppler. [Technical limitation, if present.]

Right:
CCA: [Plaque, waveform, and PSV/EDV at recorded segments.]
ICA: [Plaque distribution and lumen appearance; proximal/mid/distal PSV and EDV; highest ICA PSV and associated EDV.]
Distal CCA PSV for ratio: [ ] cm/s. ICA/CCA PSV ratio: [ ].
ECA: [PSV/EDV if acquired, patency, and relevant findings.]
Vertebral artery: [PSV where sampled, flow direction, waveform, and patency where visualized.]

Left:
[Same worksheet.]

Impression:
1. [Right ICA category and criteria applied.]
2. [Left ICA category and criteria applied.]
3. [Vertebral flow direction or other relevant finding.]

Velocity worksheet and IAC interpretation

For laboratories following the Intersocietal Accreditation Commission (IAC) modified Society of Radiologists in Ultrasound (SRU) criteria, the November 2023 recommendations combine ICA PSV with plaque estimate and additional parameters. This is a laboratory interpretation framework, not a stand-alone calculator. Use the diagnostic criteria validated by the laboratory and state them when needed.

These values summarize the IAC’s modified criteria and are not a substitute for the laboratory’s current validated protocol. The IAC 2021 angiographic correlation study found that the older SRU PSV threshold of 125 cm/s alone overestimated stenosis; IAC issued updated interpretation recommendations in 2023. Factors such as contralateral occlusion, low cardiac output, tandem disease, tortuosity, and calcific shadowing can alter interpretation.

Systematic review and reporting checklist

• Confirm bilateral coverage and image quality. Note calcification, tortuosity, high bifurcation, short neck, or other reasons a segment is not fully visible.
• Describe plaque location and appearance in each CCA, bulb, and ICA; distinguish plaque estimate from an exact lumen measurement.
• Record proximal, mid, and distal ICA velocities as acquired; identify the highest ICA PSV and its paired EDV.
• Record the distal CCA PSV used in the ICA/CCA ratio. Do not use a different segment silently between sides or studies.
• Describe spectral broadening, post-stenotic turbulence, dampened distal waveforms, and flow direction when present.
• Assess vertebral flow direction and waveform on each side when visualized. The ICA stenosis velocity categories do not classify vertebral artery disease.
• State the criteria or local protocol used and compare with prior studies when technically comparable.

Fictional examples

Normal study

Indication: Transient visual disturbance.
Comparison: None available.
Technique: Bilateral extracranial carotid and vertebral duplex ultrasound using grayscale, color, and spectral Doppler.

Findings:
No significant plaque is identified in either carotid system. The right ICA PSV is 82 cm/s and EDV is 24 cm/s; distal CCA PSV is 94 cm/s, for an ICA/CCA PSV ratio of 0.9. The left ICA PSV is 88 cm/s and EDV is 27 cm/s; distal CCA PSV is 96 cm/s, for a ratio of 0.9. No focal velocity increase or post-stenotic turbulence is seen. Both vertebral arteries demonstrate antegrade flow.

Impression:
No hemodynamically significant internal carotid artery stenosis by the laboratory's IAC-modified criteria. Antegrade vertebral artery flow bilaterally.

Moderate right ICA stenosis

Indication: Carotid bruit.
Comparison: None available.
Technique: Bilateral extracranial carotid and vertebral duplex ultrasound using grayscale, color, and spectral Doppler.

Findings:
Mixed plaque at the right carotid bulb extends into the proximal ICA, with an estimated diameter reduction greater than 50%. Right ICA PSV is 194 cm/s with EDV 58 cm/s. Distal CCA PSV is 91 cm/s; ICA/CCA PSV ratio is 2.1. Mild spectral broadening is present. The left ICA has no significant plaque or focal velocity increase. Vertebral flow is antegrade bilaterally.

Impression:
1. Right proximal ICA stenosis in the 50–69% range by IAC-modified criteria.
2. No hemodynamically significant left ICA stenosis.
3. Antegrade vertebral artery flow bilaterally.

Near occlusion or an inadequate window

If severe grayscale narrowing is present but the ICA PSV is unexpectedly low, do not automatically assign a lower stenosis category. Review color filling, distal waveform, cardiac output, and technical quality; consider near occlusion and state when the category cannot be confidently assigned. If acoustic shadowing prevents assessment, say which segment is obscured and avoid a reassuring percentage estimate.

Keep ultrasound and CTA/MRA methods separate

Carotid duplex categories are based on ultrasound morphology and hemodynamics, interpreted with a laboratory’s validated velocity criteria. NASCET percentage on CTA or MRA is based on lumen measurements and a distal reference segment. Do not convert a PSV into a NASCET percentage or describe the two as interchangeable. See NASCET versus ECST measurement on CTA or MRA for the separate cross-sectional measurement method.

References

1. Intersocietal Accreditation Commission. Updated Recommendations for Carotid Stenosis Interpretation Criteria. November 1, 2023. IAC recommendations (opens in a new tab)
2. American Institute of Ultrasound in Medicine. Practice Parameter for the Performance of an Ultrasound Examination of the Extracranial Cerebrovascular System, 2026 Revision. AIUM parameter (opens in a new tab)
3. Gornik HL, et al. Optimization of duplex velocity criteria for diagnosis of internal carotid artery stenosis: a report of the IAC Vascular Testing Division Carotid Diagnostic Criteria Committee. Vasc Med. 2021;26:515–525. doi:10.1177/1358863X211011253 (opens in a new tab)

This educational worksheet does not establish a patient’s stenosis grade. Check the current local criteria, image quality, clinical context, and comparison studies before signing.