Transcranial Doppler
transcranial Doppler · TCD ultrasound · brain blood flow ultrasound · TCD
The doctor uses ultrasound through the skull to see how blood flows in the brain's vessels. It is safe and painless.
For dizziness, after a stroke, with narrowed neck arteries, frequent headaches, or some blood disorders.
⏱ Duration: usually 20 to 40 minutes; the report is ready right away
Be sure to tell your doctor
How to prepare
- Prep. Usually none. You can eat and drink.
- Morning. Better to skip extra coffee, energy drinks, and smoking. They affect blood flow.
- Hair. No hair products or styling. Gel goes on the temple and the back of the head.
What to bring
- Your referral
- Past vessel ultrasounds
- A list of your medicines
- A comb or tissues
How it goes
- You lie on your back
- Gel is put on your temple
- The doctor presses the probe to your temple and finds the vessels
- Then the back of the head is checked. You are asked to tilt your head forward
- Sometimes you are asked to hold your breath or breathe fast
What you'll feel
- Light pressure on the temple and the back of the head
- Breathing fast can make you a little dizzy. It passes
Afterwards
- You can go back to your usual day right away
- The report is usually ready right away
- Go over the results with a neurologist
Common questions
Can ultrasound go through the skull?
Yes, through thin spots: the temple, the back of the head, and the eye socket. In some people the bone is thicker, and the view is not as clear.
Is it dangerous for the brain?
No. Ultrasound uses no radiation and does no harm.