Carotid Ultrasound Test
Overview
A carotid ultrasound is a vascular ultrasound that uses sound waves to take images of the carotid arteries. These arteries are located on both sides of the neck and carry oxygen-rich blood from the heart to the brain.
Main Uses
- Checking how blood flows through the carotid arteries.
- Finding out if artery walls are thickened.
- Detecting blood clots.
If an artery becomes blocked or narrowed, stroke risk rises. Medical teams use results from this test to decide on the best steps to lower this risk and protect brain health.
Why Carotid Ultrasound Is Recommended
Doctors use a carotid ultrasound to check for narrowing or blockages in the carotid arteries, which supply blood to the brain. When plaque made up of fat, cholesterol, and calcium narrows these arteries, the risk for stroke increases. Carotid artery disease can develop slowly and may not show symptoms until it becomes serious.
Additional Reasons for Ordering a Carotid Ultrasound
Carotid ultrasound serves several purposes beyond finding blockages. Healthcare professionals may recommend this test in the following situations:
- After Carotid Surgery: The test shows how well the artery works after a procedure called carotid endarterectomy, where a surgeon removes plaque.
- Checking Stent Placement: Doctors use it to confirm that a mesh tube, or stent, placed in a carotid artery sits correctly and functions as intended.
- Spotting Blood Clots: The ultrasound identifies blood clots (hematomas) that might block blood flow.
- Evaluating Structural Changes: It reveals changes in the artery’s walls or shape that affect blood flow.
- Assessing Plaque Features: Doctors can examine the characteristics and thickness of plaque in the artery to assess the risk of heart or artery problems elsewhere, such as coronary artery disease.
- Monitoring During Heart Valve Surgery: Surgeons sometimes use carotid ultrasound during heart valve surgery on the aorta to track blood flow and stroke risk.
- Aiding with 3D Modeling: Technicians create a 3D view of the artery to help make the diagnosis more precise.
| Risk Factor | Why It Matters |
|---|---|
| High Blood Pressure | Can damage arteries over time. |
| Diabetes | Increases risk for artery problems. |
| High Cholesterol | Leads to plaque build-up. |
| Family History | Genetics raise the risk of artery disease. |
| Previous TIA or Stroke | Higher chance of future strokes. |
| Arteriosclerosis | Hardening of arteries narrows vessels. |
| Carotid Bruit | Possible sign of narrowed blood flow. |
Doctors use carotid ultrasound to help prevent strokes and manage risk in people with diabetes, high blood pressure, high cholesterol, and other cardiovascular conditions. The test is painless and does not use radiation, making it a safe choice for many patients.
Possible Concerns
Carotid ultrasound is very safe and does not cause harm. Some people may feel mild pressure during the test, but it is painless. No lasting side effects or risks occur with this procedure.
Getting Ready
Before a carotid ultrasound, people should wear a loose shirt that opens at the collar and remove any necklaces or dangling earrings. Following all healthcare instructions is also important. Good preparation helps the test go smoothly and supports accurate results.
What You Can Expect
How the Test Is Performed
A trained ultrasound technician uses a small device called a transducer. This device sends ultrasonic sound waves through the skin to the tissues and blood vessels in the neck. The echo from these waves bounces back, and the system creates images of the carotid arteries and shows blood flow within them.
Sometimes, a special method called Doppler ultrasound helps show the movement and speed of blood through the arteries. The computer turns the signals into pictures or graphs that let a radiologist or doctor check for any narrowing or blockages. Advanced technology now produces sharper images. This exam usually lasts about 30 minutes.
During the Test
You will lie flat on your back, often with your head turned to the side for better access to the neck. The ultrasound technician applies a layer of warm gel to the neck, directly over the carotid arteries. This gel helps the sound waves travel clearly.
Next, the technician gently presses the transducer against the skin. Throughout the test, you should not feel pain. If you feel any discomfort, the technician can adjust the pressure or positioning.
Findings
In some cases, doctors may order more tests if the ultrasound does not provide enough information about the blockage or blood flow in the carotid arteries. These methods allow doctors to determine the extent of narrowing, check for blockages, and identify other problems that could increase the risk of stroke or brain injury.
Types of Further Tests
| Test | What it Shows | When Used |
|---|---|---|
| CTA | Detailed blood vessel images, blockages | When ultrasound is unclear or for surgical planning. |
| MRI/MRA | Plaque, bleeding, vessel changes, brain tissue | When brain injury or TIA is suspected, for detailed images. |
| Contrast-Enhanced Ultrasound | Vessel stiffness, early blockages | For finding early disease or changes not visible on standard. |
| 3D Ultrasound | 3D view of arteries and plaques | Used with ultrasound for a more complete picture. |
Computed Tomography Angiography (CTA): A CTA scan uses specialized X-ray images to take a closer look at the carotid arteries. Sometimes a contrast dye is injected into a vein, making blood vessels easier to see. This test provides more detail than a regular ultrasound and can help doctors spot the exact location and amount of narrowing or blockages.
Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA): An MRI uses a strong magnet and radio waves to create clear images of organs and soft tissues, including the brain. An MRA also shows blood vessels in detail. These tests help doctors find plaque buildup, bleeding, and other changes linked to stroke or transient ischemic attack. They also reveal whether there are additional brain or coronary artery problems that need treatment.
Contrast-Enhanced Ultrasound: For this scan, doctors inject a safe contrast agent into a vein. The contrast helps them check how stiff the carotid arteries are and can show early hardening of the vessels, which increases the risk of blockages. It also allows doctors to find small changes that may not show up well on a regular ultrasound.
3D Ultrasound: A 3D ultrasound creates three-dimensional pictures of the arteries. This method helps doctors measure how much plaque is present and check for lumps or thick spots that could disturb blood flow. However, it sometimes underestimates how much narrowing there is, so doctors often use it alongside other tools.
