Transcranial Doppler ultrasound

Transcranial Doppler ultrasonography; TCD ultrasonography; TCD; Transcranial Doppler study

Transcranial doppler ultrasound (TCD) is a diagnostic test. It measures blood flow to and within the brain.

How the Test is Performed

TCD uses sound waves to create images of the blood flow inside the brain.

This is how the test is performed:

You lie on your back on a padded table with your head and neck on a pillow. Your neck is stretched slightly. Or you may sit on a chair.
The technician applies a water-based gel on your temples and eyelids, under your jaw, and at the base of your neck. The gel helps the sound waves get into your tissues.
A wand, called a transducer, is moved over the area being tested. The wand sends out sound waves. The sound waves go through your body and bounce off the area being studied (in this case, your brain and blood vessels).
A computer looks at the pattern that the sound waves create when they bounce back. It creates a picture from the sound waves. The Doppler creates a "whooshing" sound, which is the sound of your blood moving through the arteries and veins.
The test can take 30 minutes to 1 hour to complete.

How to Prepare for the Test

No special preparation is needed for this test. You do not need to change into a medical gown.

Remember to:

Remove contact lenses before the test if you wear them.
Keep your eyes closed when gel is applied to your eyelids so you don't get it in your eyes.

How the Test will Feel

The gel may feel cold on your skin. You may feel some pressure as the transducer is moved around your head and neck. The pressure should not cause any pain. You may also hear a "whooshing" sound. This is normal.

Why the Test is Performed

The test is done to detect conditions that affect blood flow to the brain:

Narrowing or blockage of the arteries in the brain
Stroke or transient ischemic attack (TIA)
Stroke
A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack. " If blood flow is cut off for longer th...
Image

Read Article Now Book Mark Article
Transient ischemic attack
A transient ischemic attack (TIA) occurs when blood flow to a part of the brain stops for a brief time. A person will have stroke-like symptoms for ...
Image

Read Article Now Book Mark Article
Bleeding in the space between the brain and the tissues that cover the brain (subarachnoid hemorrhage)
Subarachnoid hemorrhage
Subarachnoid hemorrhage is bleeding in the area between the brain and the thin tissues that cover the brain. This area is called the subarachnoid sp...

Read Article Now Book Mark Article
Ballooning of a blood vessel in the brain (cerebral aneurysm)
Cerebral aneurysm
An aneurysm is a weak area in the wall of a blood vessel that causes the blood vessel to bulge or balloon out. When an aneurysm occurs in a blood ve...
Image

Read Article Now Book Mark Article
Change in pressure inside the skull (intracranial pressure)
Sickle cell anemia, to assess stroke risk
Sickle cell anemia
Sickle cell disease is a disorder passed down through families. The red blood cells that are normally shaped like a disk take on a sickle or crescen...
Image

Read Article Now Book Mark Article

Normal Results

A normal report shows normal blood flow to the brain. There is no narrowing or blockage in the blood vessels leading to and within the brain.

What Abnormal Results Mean

An abnormal result means an artery may be narrowed or something is changing the blood flow in the arteries of the brain.

Risks

There are no risks with having this procedure.

Open References

References

Defresne A, Bonhomme V. Multimodal monitoring. In: Prabhakar H, ed. Essentials of Neuroanesthesia. Cambridge, MA: Elsevier Academic Press; 2017:chap 9.

Ellis JA, Yocum GT, Ornstein E, Joshi S. Cerebral and spinal cord blood flow. In: Cottrell JE, Patel P, eds. Cottrell and Patel's Neuroanesthesia. 6th ed. Philadelphia, PA: Elsevier; 2017:chap 2.

Matta B, Czosnyka M. Transcranial doppler ultrasonography in anesthesia and neurosurgery. In: Cotrell JE, Patel P, eds. Cottrell and Patel's Neuroanesthesia. 6th ed. Philadelphia, PA: Elsevier; 2017:chap 7.

Newell DW, Monteith SJ, Alexandrov AV. Diagnostic and therapeutic neurosonology. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 410.

Sharma D, Prabhakar H. Transcranial Doppler ultrasonography. In: Prabhakar H, ed. Neuromonitoring Techniques. Cambridge, MA: Elsevier Academic Press; 2018:chap 5.

Endarterectomy - illustration
Endarterectomy is a surgical procedure removing plaque material from the lining of an artery.
Endarterectomy
illustration
Cerebral aneurysm - illustration
Weakness, numbness, or other loss of nerve function may indicate that an aneurysm may be causing pressure on adjacent brain tissue. Symptoms such as a severe headache, nausea, vomiting, vision changes or other neurological changes can indicate the aneurysm has ruptured and is bleeding into the brain. A ruptured intracranial aneurysm causes intracranial bleeding and is considered very dangerous.
Cerebral aneurysm
illustration
Transient Ischemic attack (TIA) - illustration
A transient ischemic attack (TIA) is caused by a temporary state of reduced blood flow in a portion of the brain. This is most frequently caused by tiny blood clots that temporarily occlude a portion of the brain. A primary blood supply to the brain is through two arteries in the neck (the carotid arteries) that branch off within the brain to multiple arteries that supply specific areas of the brain. During a TIA, the temporary disturbance of blood supply to an area of the brain results in a sudden, brief decrease in brain function.
Transient Ischemic attack (TIA)
illustration
Atherosclerosis of internal carotid artery - illustration
The build-up of plaque in the internal carotid artery may lead to narrowing and irregularity of the artery's lumen, preventing proper blood flow to the brain. More commonly, as the narrowing worsens, pieces of plaque in the internal carotid artery can break free, travel to the brain and block blood vessels that supply blood to the brain. This leads to stroke, with possible paralysis or other deficits.
Atherosclerosis of internal carotid artery
illustration

Endarterectomy - illustration
Endarterectomy is a surgical procedure removing plaque material from the lining of an artery.
Endarterectomy
illustration
Cerebral aneurysm - illustration
Weakness, numbness, or other loss of nerve function may indicate that an aneurysm may be causing pressure on adjacent brain tissue. Symptoms such as a severe headache, nausea, vomiting, vision changes or other neurological changes can indicate the aneurysm has ruptured and is bleeding into the brain. A ruptured intracranial aneurysm causes intracranial bleeding and is considered very dangerous.
Cerebral aneurysm
illustration
Transient Ischemic attack (TIA) - illustration
A transient ischemic attack (TIA) is caused by a temporary state of reduced blood flow in a portion of the brain. This is most frequently caused by tiny blood clots that temporarily occlude a portion of the brain. A primary blood supply to the brain is through two arteries in the neck (the carotid arteries) that branch off within the brain to multiple arteries that supply specific areas of the brain. During a TIA, the temporary disturbance of blood supply to an area of the brain results in a sudden, brief decrease in brain function.
Transient Ischemic attack (TIA)
illustration
Atherosclerosis of internal carotid artery - illustration
The build-up of plaque in the internal carotid artery may lead to narrowing and irregularity of the artery's lumen, preventing proper blood flow to the brain. More commonly, as the narrowing worsens, pieces of plaque in the internal carotid artery can break free, travel to the brain and block blood vessels that supply blood to the brain. This leads to stroke, with possible paralysis or other deficits.
Atherosclerosis of internal carotid artery
illustration

A Closer Look

Self Care

Tests for Transcranial Doppler ultrasound

Transcranial Doppler ultrasound

Review Date: 4/29/2023

Reviewed By: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School of Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Health Library

Transcranial Doppler ultrasound

How the Test is Performed

How to Prepare for the Test

How the Test will Feel

Why the Test is Performed

Stroke

Transient ischemic attack

Subarachnoid hemorrhage

Cerebral aneurysm

Sickle cell anemia

Normal Results

What Abnormal Results Mean

Risks

References

Endarterectomy - illustration

Endarterectomy

Cerebral aneurysm - illustration

Cerebral aneurysm

Transient Ischemic attack (TIA) - illustration

Transient Ischemic attack (TIA)

Atherosclerosis of internal carotid artery - illustration

Atherosclerosis of internal carotid artery

Endarterectomy - illustration

Endarterectomy

Cerebral aneurysm - illustration

Cerebral aneurysm

Transient Ischemic attack (TIA) - illustration

Transient Ischemic attack (TIA)

Atherosclerosis of internal carotid artery - illustration

Atherosclerosis of internal carotid artery

A Closer Look

Self Care

Tests for Transcranial Doppler ultrasound

Related Information