A carotid duplex scan is a non-invasive medical imaging technique used to examine the carotid arteries located in the neck. This procedure combines two ultrasound technologies: traditional B-mode imaging and Doppler ultrasound. B-mode provides visual images of the artery’s structure, while Doppler ultrasound measures the speed and direction of blood flow within these vessels. Together, these methods offer a comprehensive view of the carotid arteries without the need for incisions or radiation.
Why a Carotid Duplex is Performed
Medical professionals recommend a carotid duplex scan to assess the health of the carotid arteries, which supply blood to the brain. It primarily detects carotid artery disease, where fatty deposits (plaque) accumulate on the artery walls. This buildup, called atherosclerosis, can narrow the arteries, impeding blood flow.
The scan assesses stroke risk. It identifies blockages or narrowing from plaque, helping doctors determine the likelihood of a clot causing a stroke. It also evaluates individuals who have experienced a transient ischemic attack (TIA), or “mini-stroke.” A TIA is a temporary interruption of blood flow to the brain, and the scan helps pinpoint underlying carotid artery issues.
For diagnosed patients, the scan monitors carotid artery disease. It tracks plaque progression and treatment effectiveness. It also follows up after surgical interventions like carotid endarterectomy (plaque removal) or carotid artery stenting (artery opening).
The scan can also detect other vascular issues. These include aneurysms (bulges in the artery wall) or dissections (tears in the inner lining). Its detailed imaging allows visualization of these abnormalities.
How a Carotid Duplex is Performed
The carotid duplex exam is a straightforward, comfortable procedure. Patients lie on their back, often with their head slightly tilted, for better neck access. This position ensures clear visibility of the carotid arteries.
Before the scan, a clear, water-based gel is applied to the neck over the carotid arteries. This gel helps the handheld transducer glide smoothly and ensures optimal sound wave transmission. The transducer emits high-frequency sound waves that travel into the body, bouncing off red blood cells and tissues.
The transducer captures these reflected sound waves, sending them to a computer that translates them into real-time images. During the Doppler exam, the technologist activates an audio function, allowing “whooshing” sounds to be heard. These sounds represent blood flow, with changes in pitch and volume indicating variations in speed and potential blockages. The procedure typically takes 30 to 60 minutes.
Understanding Carotid Duplex Results
A radiologist or vascular specialist interprets the images and data, providing a detailed report. B-mode images reveal plaque presence, allowing specialists to observe its size, texture, and location. They also assess vessel wall thickness, as increased thickness can indicate arterial disease.
The Doppler component provides information about blood flow velocity. Blood flow speed can indicate narrowing; faster flow in a segment suggests constriction. This data helps determine the degree of stenosis (arterial narrowing), categorized as mild, moderate, or severe.
Normal results show clear arteries with smooth inner linings and unobstructed blood flow. Abnormal findings include plaque, ranging from small deposits to larger lesions. Significant stenosis, a substantial narrowing impeding blood flow to the brain, is the most concerning abnormal finding.
These results guide medical decisions. Mild plaque may warrant lifestyle modifications and medication to prevent progression. Moderate or severe stenosis may lead to discussions about intensive medical management or surgical options like endarterectomy or stenting to reduce stroke risk.
Preparing for Your Carotid Duplex Exam
Preparation for a carotid duplex exam is straightforward, requiring no extensive special preparations. Patients do not need to fast or follow specific dietary restrictions. Wear comfortable, loose-fitting clothing that allows easy neck access for the sonographer.
Continue all regular medications as prescribed, unless instructed otherwise by your doctor. No medication schedule adjustments are needed for this scan. Remove any necklaces, earrings, or other jewelry around the neck or ears, as these can interfere with the transducer or image clarity. Ask your healthcare provider or imaging staff any questions before or during the exam.