Transcranial Doppler

What is Transcranial Doppler Ultrasound?

Transcranial Doppler ultrasound (abbreviated TCD) is a diagnostic procedure used to examine the blood vessels inside the brain. This procedure uses high-frequency ultrasound waves to visualize and analyze blood flow through the brain’s arteries and arterioles.

How does transcranial doppler differ from regular ultrasound?

Transcranial Doppler ultrasound (TCD) and regular ultrasound (ultrasonography) are two different methods of ultrasound imaging that are used for different purposes and on different parts of the body. Here are the key differences between these two diagnostic methods:

Where and why TCD is applied?

Transcranial Doppler ultrasound (TCD) is applied to the patient’s head and neck to study blood flow through the blood vessels inside the brain, as well as the neck blood vessels that supply blood to the brain. This method is often used to evaluate cerebrovascular conditions, such as strokes and vasospasms.

Regular ultrasound (ultrasonography) can be applied to different parts of the body, including the abdomen, pelvis, heart, breasts and other organs. This method is used to visualize structures inside the body, such as organs, tissues and blood vessels, to diagnose various medical conditions.

The working principles:
TCD uses the principle of the Doppler effect to monitor blood flow through blood vessels. It measures changes in the frequency of ultrasound waves reflected by moving red blood cells.

A regular ultrasound uses ultrasound waves to create images of the body’s internal structures. Images are formed based on the reflection of ultrasound waves from different tissues and organs in the body.

Primary use:

TCD is used to evaluate the cerebrovascular system and can identify problems such as narrowing or closing of blood vessels in the brain.
Regular ultrasounds are used for a variety of purposes, including monitoring pregnancy, diagnosing gastrointestinal problems, evaluating the heart and blood vessels, detecting tumors, and many other diagnostic purposes.


TCD requires placing ultrasound sensors on the patient’s head or neck to gain access to the brain’s blood vessels.
Regular ultrasound usually requires placing a sensor directly on the patient’s skin over the area to be examined.

What conditions and diseases can be diagnosed by transcranial Doppler ultrasound?

Transcranial Doppler ultrasound (TCD) can be used to diagnose and monitor various conditions and diseases related to blood flow in the brain. Here are a few conditions and diseases that can be diagnosed or evaluated using TCD:


TCD is often used to assess blood flow in the brain of patients who have had a stroke or are at risk of stroke. This technique can help identify narrowing of blood vessels (stenosis) or blood clots that can cause a stroke.


TCD is used to monitor vasospasms, the narrowing of blood vessels in the brain that can occur after subarachnoid hemorrhage from an aneurysm. Monitoring vasospasm helps plan appropriate treatment to prevent potential complications.

Arteriovenous malformations (AVMs)

TCD can be used to assess blood flow through arteriovenous malformations, which are abnormal connections between arteries and veins in the brain. This technique helps assess the risk of bleeding from an AVM.

TIA (transient ischemic attack):

TCD is used to assess blood flow in patients who have had a transient ischemic attack, which is a temporary disruption of blood flow to the brain that can be a precursor to a stroke.

Vertebral artery syndrome (VAD)

TCD can be used to assess blood flow through the vertebral arteries that supply the brain. VAD can cause symptoms such as dizziness, headache, and vision changes.

Migraine with aura

TCD can be used to examine blood flow during migraine with aura to better understand how changes in blood flow can cause symptoms of this type of migraine.

Vascular disorders of the brain

TCD can be useful in the evaluation of various vascular disorders of the brain, including moyamoya disease and vascular dysplasia.

Diagnosis of brain tumors

TCD is sometimes used to assess blood flow near brain tumors, which can help distinguish benign from malignant tumors.
It is important to note that TCD, although a useful tool for evaluating the cerebrovascular system, can only be one part of the diagnostic process. In some cases, other diagnostic tests and scans, such as a CT (computed tomography) scan or MRI (magnetic resonance imaging) of the brain, may be needed to confirm the diagnosis and plan treatment.

What to expect before transcranial doppler?

Preparation for transcranial Doppler ultrasound (TCD) is usually not complicated, but there are some steps that the patient should take before the examination itself. Here are some of the typical steps to prepare for TCD:

  • Tell the healthcare provider about your conditions and medications: Before the exam, tell the healthcare provider about any medical conditions you have, as well as any medications you are taking. This includes any drug allergies.
  • Remove jewelry and metal objects: Before entering the examination room, you may need to remove jewelry, glasses, and other metal objects, as metal can interfere with the ultrasound.
  • Clothing: The clothing you wear during the examination should be comfortable and allow easy access to the head and neck, as the ultrasound sensor will be placed in those areas.
  • Avoid caffeine and tobacco: It is recommended to avoid caffeine and tobacco consumption at least a few hours before the examination, as these factors can affect blood flow.
  • Questions about contrast media: In some cases, TCD can be performed with contrast media, but this will be explained to you in advance and the doctor will inform you of all the necessary information.

What to expect during transcranial doppler?

  • During a transcranial Doppler ultrasound (TCD), expect the following steps and procedures:
    Patient preparation: Before the examination begins, the medical staff will instruct you on how to prepare. This includes the removal of jewelry and other metal objects, as well as notification of any dietary restrictions and caffeine or tobacco intake, depending on specific requirements.
  • Positioning on the examination table: After preparation, you will lie on the examination table. You usually lie on your back or lean slightly backwards.
  • Attaching the sensor: The ultrasound technician or doctor will attach the sensor to your head or neck, usually at the temple. A sensor is a device that emits and receives ultrasonic waves.
  • Ultrasound gel: At the place where the sensor is placed, an ultrasound gel is applied. The gel helps in better transmission of ultrasound waves between the sensor and the skin, which allows a better picture of the blood flow.
  • Blood flow monitoring: The technician will begin the exam and use a sensor to monitor blood flow through the blood vessels inside the brain. During the examination, you may hear sounds corresponding to blood flow.
  • Data recording: During the examination, data on blood flow rate and other relevant parameters are recorded and can be visualized on the monitor.
  • Completion of the examination: After the necessary data has been collected, the technician will remove the sensor and gel from your skin.

How long does it take to have TCD?

The duration of the TCD procedure usually lasts about 30-60 minutes, and may vary depending on the purpose of the examination and the complexity of the situation.

What equipment is used for transcranial Doppler ultrasound?

Transcranial Doppler ultrasound (TCD) uses specific equipment that allows doctors and technicians to view blood flow in the brain’s arteries and arterioles. Here are the basic components of the equipment used for TCD:

  • Ultrasound machine: The central part of the equipment is the ultrasound machine or device. This device generates ultrasound waves and receives reflections of those waves to create images and sounds of blood flow. The device allows setting the frequency and penetration depth of ultrasonic waves.
  • Ultrasonic sensors (transducers): Sensors are devices that emit and receive ultrasonic waves. For TCD, sensors specially designed to access blood vessels in the brain are used. Sensors are usually placed on the temple or other areas of the head and neck to provide access to the cerebral arteries.
  • Ultrasound gel: Gel is applied to the skin before the sensor is placed. This gel helps improve the conductivity of ultrasound waves and ensures better contact between the sensor and the skin. It also helps reduce air bubbles between the sensor and the skin, which could affect image quality.
  • Monitor: All blood flow information is displayed on the monitor. The monitor usually displays color images and numerical values related to the blood flow rate.
  • Computer and software: Information collected during a TCD examination can be processed and analyzed using a computer and special software. This allows doctors to get accurate blood flow data and to make diagnoses or assess the condition of the blood vessels.

What are the steps after the transcranial Doppler ultrasound procedure?

TCD is usually a painless and non-invasive procedure. After the examination, you can return to your daily activities without special restrictions. It’s important to work with your healthcare team and follow their guidelines to get the most out of your exam and understand potential diagnoses or treatment recommendations.

How and when will you get the transcranial doppler results?

The time and method of obtaining transcranial Doppler ultrasound (TCD) results depends on many factors, including the specific practice or hospital where the examination was performed, the urgency of the diagnosis, and your medical condition.

After you complete a TCD scan, the results will not usually be available immediately. The time it takes to analyze the results can vary, but in most cases you can expect to wait from a few hours to a few days. After the results are available, the next step is to schedule a consultation with your doctor or radiologist. At this consultation, the doctor will provide you with information about the results of the TCD examination and explain their meaning in the context of your medical condition.

Talking to the doctor: The most common step after a TCD scan is to talk to the doctor or radiologist who performed the test or will analyze the results. The doctor will provide you with information about the test results and explain their meaning in the context of your medical condition.

Diagnosis and interpretation of the results: Based on the results of the TCD examination, the doctor will try to diagnose or evaluate the condition of your brain blood vessels. Depending on the type of examination and the reason for which it was performed, the results can be used to diagnose strokes, vascular disorders, vasospasms and other cerebrovascular conditions.

Treatment or follow-up planning: Based on the diagnosis and the results of the TCD examination, the doctor will decide on the appropriate treatment or follow-up plan. In some cases, this may include additional tests or procedures, a change in medication, physical therapy, or other therapeutic interventions.

Patient information: Your doctor will provide you with information about your health, treatment options, and prognosis. It’s important to ask questions and talk to your doctor to better understand your condition and what to expect in the future.
Condition monitoring: In some cases, TCD is used to monitor changes in blood flow over time. This may be particularly important for patients who are susceptible to cerebrovascular problems, such as those who have suffered strokes or are at risk of vasospasm.

Additional Tests or Treatments: Based on the results of the TCD examination, additional diagnostic tests or therapeutic procedures may need to be performed to better understand or treat your medical condition.

Understanding Transcranial Doppler Results

Understanding the results of transcranial Doppler ultrasound (TCD) can be complex, as it depends on the specific parameters and findings recorded during the examination. Here are some key aspects to consider when interpreting the results of a TCD review:

Blood flow rate

One of the basic parameters measured during a TCD examination is the blood flow rate through the cerebral arteries and arterioles. This data is usually displayed as numbers, such as centimeters per second (cm/s) or meters per second (m/s). The speed of blood flow may indicate normal flow, narrowing (stenosis) of the blood vessels, or accelerated flow which may be a sign of a problem.

Direction of blood flow:

TCD can also detect the direction of blood flow. Normally, blood moves forward through the arteries to the brain. Changes in flow direction may indicate vasospasm, thrombosis, or other cerebrovascular problems.
Asymmetry in flow: The doctor will analyze the symmetry of blood flow between the left and right sides of the brain.

Asymmetry may indicate a narrowing or other problem in one of the cerebral arteries.
Middle cerebral artery (MCA) time: TCD can also measure the time it takes blood to travel through the middle cerebral arteries (MCA). This is often used to assess blood flow in the deeper parts of the brain.
Pulsatility: Pulsatility refers to changes in blood flow rate during the cardiac cycle. Its presence or absence can provide information about the state of the blood vessels and the heart.

Blood Flow Sounds

During a TCD scan, the doctor may listen for blood flow sounds. Abnormal sounds, such as murmurs or turbulence, may indicate problems with blood flow.

Comparison with reference values: It is important to remember that the results of a TCD examination are often compared with reference values and normal ranges of blood flow velocities for certain cerebral arteries. Deviations from normal values may indicate potential problems.

Clinical context

The final interpretation of TCD results is usually done in the context of your symptoms, medical history, and other available information. TCD is a diagnostic tool, but its results must be combined with the overall clinical picture.

Why is the transcranial doppler test considered safe?

The transcranial Doppler (TCD) test is considered a safe diagnostic procedure for several reasons:

  • Non-invasive procedure: TCD is non-invasive, meaning it does not require the use of needles, catheters or invasive interventions. The sensor is simply placed on the patient’s scalp or neck to measure blood flow in the cerebral arteries.
  • No ionizing radiation: Unlike some other diagnostic methods such as CT (computed tomography) or conventional X-rays, TCD does not use ionizing radiation. This means that patients are not exposed to the harmful effects of radiation during the examination.
  • Minimal risk of complications: TCD does not involve any surgical procedures or the use of intravenous contrast agents, which reduces the risk of complications such as allergic reactions to contrast agents or infections.
  • Speed and simplicity: The TCD procedure is usually quick and simple, and patients can usually leave the clinic or hospital immediately after the examination. There is no need for recovery or hospitalization after a TCD examination.
  • Accessibility: TCD is widely available and frequently used in many medical facilities. Its relative affordability and rapid performance make it a useful tool for assessing blood flow in cerebral arteries.
    Although TCD is considered a safe procedure, it is important to emphasize that any medical test or procedure carries some level of risk or discomfort.

Are there any side effects from the transcranial Doppler ultrasound test?

The transcranial Doppler ultrasound (TCD) test is generally considered safe and has very few side effects or complications. Here are some possible side effects, although they are extremely rare:

Skin irritation: The gel used to improve the conduction of ultrasound waves may cause mild skin irritation where the sensor is placed. This is usually temporary and is usually easily resolved by cleaning the skin.

Allergic reactions: Although allergic reactions to ultrasound gel are rare, they can occur in some people. Allergic reactions usually include itching, redness and rash on the skin. If you suspect that you are allergic to the gel, inform your healthcare professional.

Dizziness or nausea: During a TCD examination, patients are usually supine or leaned back, which may cause mild dizziness or nausea in some individuals. This is usually transient and goes away after you return to an upright position.

It is important to note that serious side effects of TCD examinations, such as complications or serious allergic reactions, occur extremely rarely.

The advantages of TCD examinations, such as the ability to assess blood flow in cerebral arteries without the use of ionizing radiation or invasive procedures, usually outweigh possible side effects.

Consulting with your healthcare provider about transcranial doppler (TCD) is an important step in preparing for your exam and understanding what to expect during the diagnostic procedure.

  • Here are some key questions to consider during your consultation with your healthcare team:
    • Why is a TCD examination recommended in your case? What are the indications or symptoms that led to this examination?
  • How to prepare for a TCD examination? Are there any special guidelines regarding the intake of food, drink or medication before the examination?
  • How long does a TCD examination usually take and what happens during the procedure itself? You can ask about how you will be positioned during the examination.
  • Discuss possible side effects or discomfort during the TCD examination and how they can be managed.
  • Is the TCD scan safe? How are the risks minimized and how are potential allergic reactions to the ultrasound gel handled?
  • When can you expect TCD test results and how will these results be interpreted? How will the results be communicated to you and how will you be informed about the diagnosis or treatment plan?
  • Are there alternatives to TCD screening that should be considered? Your doctor may consider other diagnostic procedures that may be useful in your case.

Remember that you have the right to ask any personal questions or express your concerns about the TCD examination. Your healthcare team should be open to answering these questions and providing additional information according to your needs.
If a diagnosis or further treatment is recommended based on the results of the TCD scan, discuss planning your next steps and how you will work with your doctor to manage your medical condition.

Collaboration and communication with your health care team are key to a successful TCD examination and adequate diagnosis or treatment. Do not hesitate to ask questions and ask for additional information so that you are informed and feel safe throughout the process.

TCD is a useful tool for evaluating the cerebrovascular system and assists physicians in making diagnoses and planning appropriate treatment for various neurological diseases and conditions. It is important to work with your healthcare team and follow all of their guidelines to ensure that the TCD scan is performed in the best possible way and provides accurate information about your cerebrovascular system.

Transcranial doppler (TCD) – Price

The price of this kind of procedure is 7400 RSD.