You've had your carotid ultrasound and the report has arrived. It's dense with abbreviations, velocity measurements, and clinical terminology that wasn't covered in any class you took. This guide walks through what the key values actually mean — so you can have a more informed conversation with your physician.
By BlackPoint's registered sonographer
Medically reviewed by Dr. Glenn Gandelman, MD, MPH, FACC, FASE — Board-Certified Cardiologist
February 2025
✓Registered cardiac & vascular sonographer
✓ASE Member — Echo Standards
✓Read in an IAC-accredited lab
✓Board-Certified Cardiologist Review
Your carotid ultrasound report arrives via encrypted email within 24 to 48 hours of your appointment. It contains measurements, clinical terminology, and conclusions that can be confusing without context. This guide explains what each section means in plain language so you can read your own report with confidence before discussing it with your physician.
The Basic Structure of a Carotid Report
A standard carotid duplex report covers four main areas: vessel anatomy, plaque characterization, stenosis quantification, and diastolic velocity assessment. Each carotid artery, right and left, is evaluated separately. The report describes the common carotid artery, the internal carotid artery, and the external carotid artery on each side.
Intima-Media Thickness (IMT): What Your Number Means
IMT measures the thickness of the innermost two layers of the carotid artery wall in millimeters. Normal IMT for most adults is below 0.9 mm. Values above 1.0 mm indicate significant wall thickening consistent with early atherosclerosis. IMT above 1.5 mm or focal thickening meeting specific criteria is classified as a plaque.
Your IMT is typically compared to age- and sex-matched reference ranges. A finding of IMT in the 75th percentile for your age means your arterial walls are thicker than 75 percent of people your age. This is clinically meaningful because it suggests accelerated arterial aging and an above-average atherosclerotic burden.
An elevated IMT does not mean a stroke is imminent. It means your arteries have accumulated more structural change than expected for your age, which is important information for risk stratification and treatment decisions. Your physician uses it alongside other risk factors.
Plaque: What the Report Describes
When the report identifies plaque, it describes several characteristics. Location refers to which artery and at what anatomical landmark. Size refers to the dimensions of the plaque in millimeters. Echogenicity describes how the plaque appears on ultrasound: hyperechoic plaques are calcified and generally more stable, while hypoechoic or heterogeneous plaques may be softer and carry higher rupture risk. Surface characterization notes whether the plaque surface appears smooth or irregular.
The presence of plaque is not an emergency finding in the absence of significant stenosis. Many people have small stable carotid plaques that are monitored over time without intervention. The report tells your physician what is there, how it looks, and how to follow it.
Stenosis: Understanding the Percentage
If the report notes a stenosis, it is expressed as a percentage reduction in the arterial lumen. The commonly used classification is: less than 50 percent is mild stenosis, 50 to 69 percent is moderate, 70 to 99 percent is severe, and 100 percent is complete occlusion. Under the Society for Vascular Surgery's 2022 clinical practice guidelines, carotid endarterectomy is recommended as first-line treatment for low-risk surgical patients with symptoms and 50 to 99 percent stenosis, and for patients without symptoms and 70 to 99 percent stenosis. Whether any procedure is appropriate is a decision for your physician.
Haven't had a carotid ultrasound yet? BlackPoint Diagnostics performs carotid ultrasound at our Falmouth imaging center, or at your home or workplace. No referral required; a board-certified cardiologist reviews every study within 24–48 hours. $397 in Falmouth, $597 on-site.
Already had a carotid ultrasound elsewhere? A repeat study gives your physician a second set of measurements to compare with the first: plaque, IMT and flow velocities, measured the same way. $397 in Falmouth, $597 on-site.
Peak Systolic Velocity (PSV) and End Diastolic Velocity (EDV)
These are flow velocity measurements taken with Doppler ultrasound. Velocity increases when an artery is narrowed, similar to how water moves faster through a narrow nozzle. An internal carotid PSV above 125 cm/s suggests at least 50 percent stenosis. Above 230 cm/s typically indicates severe stenosis. These numbers allow the radiologist or cardiologist to quantify stenosis even when imaging alone is inconclusive.
The Impression and Recommendations Section
This is the most important part of your report. The reviewing cardiologist summarizes all findings into a clinical assessment and recommends a follow-up interval. Common recommendations include repeat imaging in one to two years for stable mild findings, referral to vascular surgery for severe stenosis, and correlation with symptoms if any are present. If no action is recommended and the report is negative or mildly abnormal, that is genuinely reassuring information.
BlackPoint reports are written by Dr. Glenn Gandelman, MD, MPH, FACC, FASE, with a patient-readable summary as well as the technical findings. If you have questions about your report after receiving it, you are welcome to call us at (207) 409-7797.
Frequently Asked Questions
What is the basic structure of a carotid ultrasound report?
A standard carotid duplex report covers four main areas: vessel anatomy, plaque characterization, stenosis quantification, and diastolic velocity assessment. Each carotid artery, right and left, is evaluated separately covering the common carotid, internal carotid, and external carotid arteries on each side.
What does intima-media thickness (IMT) mean on a carotid report?
IMT measures the thickness of the innermost two layers of the carotid artery wall in millimeters. Normal IMT is below 0.9 mm. Values above 1.0 mm indicate significant wall thickening consistent with early atherosclerosis. IMT above 1.5 mm or focal thickening meeting specific criteria is classified as plaque.
What does the stenosis percentage mean in a carotid report?
Stenosis is expressed as percentage reduction in arterial lumen. Less than 50 percent is mild, 50-69 percent is moderate, 70-99 percent is severe, and 100 percent is complete occlusion. Under the Society for Vascular Surgery's 2022 guidelines, endarterectomy is recommended as first-line treatment for low-risk surgical patients with symptoms and 50 to 99 percent stenosis, and for patients without symptoms and 70 to 99 percent stenosis.
What are peak systolic velocity and end diastolic velocity?
These are flow velocity measurements taken with Doppler ultrasound. Velocity increases when an artery is narrowed, similar to water moving faster through a narrow nozzle. An internal carotid PSV above 125 cm/s suggests at least 50 percent stenosis. Above 230 cm/s typically indicates severe stenosis.
What does the impression and recommendations section of a carotid report contain?
The reviewing cardiologist summarizes all findings into a clinical assessment and recommends follow-up. Common recommendations include repeat imaging in one to two years for stable mild findings, referral to vascular surgery for severe stenosis, and correlation with symptoms if present.
If you are in Southern Maine, bring your prior report. We measure plaque, IMT and flow velocities the same way, so the two studies compare directly. $397 in Falmouth, $597 on-site, read by a board-certified cardiologist, results in 24–48 hours, no referral needed.
