Transcranial Doppler Ultrasound

Transcranial doppler ultrasound is an important screening procedure for Children's Hospital of Philadelphia (CHOP) patients with certain types of sickle cell disease or thalassemia.

Important information about TCD:

A transcranial Doppler (TCD) is an ultrasound, similar to ultrasound used during pregnancy, that measures the speed of blood flowing through the blood vessels in the brain. The technician will put gel on your child's temples and rub a wand over the area.

Children with sickle cell disease type SS or Sβ0 thalassemia and who are at increased risk for stroke should have a transcranial Doppler test once a year.

Transcranial Doppler ultrasound:

  • Is noninvasive

  • Is performed in an outpatient setting

  • Lasts about 30 minutes

  • Requires the child to rest flat and remain still

Why is this test important?

If the blood supply to the brain is blocked or decreased, children with sickle cell disease may have a stroke.

What causes a stroke?

In children with SCD-SS or SCD-Sβ0, their sickled cells have a hard time moving through the blood vessels in the brain. If some cells get "stuck" and cannot move, other cells pile up behind and cause a "log jam" that blocks the blood vessels. When oxygen cannot get past the blockage to other parts of the brain, a stroke can happen. Blood vessel narrowing can also cause a similar event.

What are the signs of a stroke?

  • Headache

  • Difficulty speaking or slurred speech

  • Facial droop

  • Poor coordination

  • Extreme sleepiness

  • Difficulty moving arms and legs

Stroke is an emergency. Call your hematology team and bring your child to the hospital immediately.

What do the results mean?

Normal: Repeat the TCD in one year.

Conditional: Repeat the TCD more frequently.

Abnormal: If the test is abnormal the team may:

  1. Repeat the test.

  2. Start blood transfusion therapy.

  3. Get an MRI of the brain.

Patient instructions:

  • Your child cannot eat, drink, sleep or suck on a pacifier during the ultrasound. Make sure your child is well rested and not hungry and consider bringing a comfort item or tablet/phone with favorite videos to distract them.

  • Please arrive 30 minutes before the appointment time.

How often should a child get a transcranial Doppler?

Children ages 2-16 with sickle cell disease type SCD-SS or SCD-Sβ0 should be tested once a year.

Specific recommendations by age:

18 months:

  • Discuss stroke prevention with your child's hematologist.

  • Work with child life specialists and your sickle cell clinical team to schedule an appointment.

24–28 months:

  • Prepare your child for TCD screening before the appointment.

  • Discuss results with your sickle cell hematologist.

2–16 years:

  • Keep track of your annual TCD appointments.

  • Sometimes a TCD must be repeated because of the test results.

How can I schedule or change a transcranial Doppler appointment?

Our scheduling team will help you make or change an appointment.

Please call 215-590-7000.

TCD appointment locations:

CHOP's Buerger Center for Advanced Pediatric Care
Radiology, 2nd Floor
3500 Civic Center Blvd., Philadelphia, PA 19104
Monday to Friday, 7:30a.m.-4:30p.m.

CHOP's Main Building
3rd Floor
3401 Civic Center Blvd., Philadelphia, PA 19104
Monday to Friday, 7:30a.m.-6p.m.

 

Reviewed on June 23, 2023, by Alexandra Kaspin, RN, MSN