Carotid Artery Blockage Test Methods

The carotid arteries are two large vessels in the neck that supply blood to the brain. When blockages occur in these arteries, the decreased blood flow can starve the brain of vital oxygen and lead to stroke or death. Early detection of carotid artery disease is extremely important, and a number of testing methods are used for this purpose.

Initial Examination

• According to the National Heart Lung and Blood Institute, your doctor will begin diagnosing potential carotid artery blockages by taking your medical history. Among other things, he will ask you questions that will reveal specific signs of potential problems such as a mini-stroke or undiagnosed stroke. He will then listen to your carotid arteries with a stethoscope to detect reduced blood flow caused by artery blockage. If blockage is present, turbulent blood flow will produce a distinctive rushing sound known as a bruit.

Testing Methods

• Based on the findings of these preliminary examinations, your doctor may order any one of several tests designed to confirm the presence of carotid artery blockage.

  In a carotid duplex ultrasound, a trained ultrasound technician will place a specialized probe against your neck. This probe will send high-frequency sound waves through your neck that reflect off your blood vessels and create an image that can be viewed on an external monitor. Using this image, your doctor can observe the rate of blood flow in your carotid arteries and detect any restrictions. In most situations, this procedure is sufficient to detect any problems. However, if the results of an ultrasound exam are unclear, further testing can be done.

  In an angiography, your doctor will place a catheter into your neck arteries, then use that catheter to inject a special contrast dye. When areas injected with this dye are viewed on an X-ray, they reveal a clear picture of blood flow and artery restrictions. Be aware that this procedure carries minor risks of stroke caused by particles of contrast dye blocking oxygen to the brain.

  In a magnetic resonance angiography, technicians will use a combination of magnetic fields and radio waves to form images of your carotid arteries. To enhance the readability of these images, your doctor may also inject a form of contrast dye called gadolinium.

  Computed tomography (CT) scans are used to record two- and three-dimensional images of your brain and your carotid arteries. These images can reveal poor blood flow in your brain, as well as blockages in your neck. In some cases, your doctor may combine a CT scan with a contrast dye angiography to provide a clearer view of your arteries on the recorded images. This procedure is called computed tomography angiography (CTA).

  To indirectly check for signs of carotid artery blockage, your doctor may use another technique called oculoplethysmography. In this procedure, he will measure pulses in the arteries located at the back of your eyes to gain insight into your carotid function.

  Further treatment of your condition will depend on the results of carotid artery testing. Consult your doctor for more details.