Protocol - Stroke Risk in Children with Sickle Cell Disease - TCDi
Imaging Transcranial Doppler (TCDi) ultrasonography is an imaging technique that measures the blood flow velocity in large intracranial arteries. This TCDi protocol covers how to identify relevant intracranial landmarks and how to record and score TCDi results.
Results from Imaging Transcranial Doppler (TCDi) ultrasound should be interpreted by a medical doctor with expertise in TCDi in sickle cell disease (SCD). Additionally, the TCD results should be compared with published guidelines to determine if the subject should be receiving prophylactic red cell transfusion or require more frequent TCD or other monitoring.
The Working Group does not recommend angle correction of TCDi blood-flow velocities. Cut-points for blood flow velocities are currently based on uncorrected velocities, and new parameters need to be established for angle-corrected velocities. Instead of angle correction, investigators should optimize the velocities with various maneuvers to get the best angle by transducer position.
The Working Group notes that blood-flow velocities indicative of stroke risk can be obtained by either Transcranial Doppler (TCD) ultrasound or Imaging Transcranial Doppler (TCDi) ultrasonography. The choice of TCD or TCDi depends on the expertise and equipment available to investigators.
Imaging Transcranial Doppler Ultrasonography
Identifying Intracranial Landmarks and Major Cerebral Arteries
Krejza et al. (2000) provide standard parameters for the visualization of the anterior, middle, and posterior cerebral arteries through the temporal acoustic window in the thin temporal region of the skull.
Recording Imaging Transcranial Doppler Ultrasonography Results
Examiners should record the highest time-averaged mean blood-flow velocity using a 3-millimeter sample volume placed at the point of highest velocity as determined by color aliasing artifacts in the following arteries:
- middle cerebral artery,
- distal internal carotid artery,
- anterior and posterior cerebral arteries, and
- basilar artery.
Angle-corrected mean velocities can be obtained by automatic or manual tracing of the Doppler waveform. Uncorrected flow velocities are calculated for each artery as the product of angle-corrected velocities and the cosine of the recorded angle of insonation based on the Doppler equation.
Scoring of Uncorrected Flow Velocities
Normal: blood velocities less than 165 centimeters per second in all arteries.
Conditional: blood velocities greater than 165 centimeters per second but less than 200 centimeters per second in all arteries.
Abnormal: blood velocity of 200 centimeters per second or greater in either the internal carotid artery or the middle cerebral artery.
Personnel and Training Required
Imaging Transcranial Doppler (TCDi) ultrasonography should be administered by trained ultrasonographers and interpreted by clinicians (e.g., radiologists, neurologists, hematologists) with expertise in TCDi in children with sickle cell disease (SCD).
2 megahertz Doppler ultrasonogram with a 1.8 to 3.6 megahertz transducer.
|Specialized requirements for biospecimen collection||No|
|Average time of greater than 15 minutes in an unaffected individual||Yes|
Mode of Administration
Clinical examination and physical measurement
Toddler, Child, Adolescent
Children and adolescents aged 2 years and older with hemoglobin SS or beta-zero thalassemia disease and without a history of clinical stroke.
Transcranial Doppler (TCD) ultrasound is a valid and reliable method that has been shown in clinical trials to select children for prophylactic blood transfusion. In contrast to traditional TCD, imaging TCD allows direct visualization of the arteries under examination.
|caDSR Common Data Elements (CDE)||Stroke Imaging Doppler Ultrasound Assessment Score||4924359||CDE Browser|
|Human Phenotype Ontology||Sickle Cell Anemia||ORPHA:232||HPO|
|Human Phenotype Ontology||Anemia||OMIM:603903||HPO|
Process and Review
Protocol Name from Source
Identifying Intracranial Landmarks and Major Cerebral Arteries
Krejza, J., Mariak, Z., Melhem, E. R., & Bert, R. J. (2000). A guide to the identification of major cerebral arteries with Transcranial Color Doppler Sonography. American Journal of Roentgenology, 174, 1297-1303.
Recording and Scoring Results
Arkuszewski, M., Krejza, J., Chen, R., Kwiatkowski, J. L., Ichord, R., Zimmerman, R., Ohene-Frempong, K., & Melhem, E.R. (2012). Sickle cell disease in children: Accuracy of imaging transcranial Doppler ultrasonography in detection of intracranial arterial stenosis. The Neuroradiology Journal, 25(4), 402-410.
Adams, R. J., Brambilla, D., & Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) Trial Investigators. (2005). Discontinuing prophylactic transfusions used to prevent stroke in sickle cell disease. New England Journal of Medicine 353(26), 2769-2778.
Adams, R. J., McKie, V. C., Brambilla, D., Carl, E., Gallagher, D., Nichols, F. T., Roach, S., Abboud, M., Berman, B., Driscoll, C., Files, B., Hsu, L., Hurlet, A., Miller, S., Olivieri, N., Pegelow, C., Scher, C., Vichinsky, E., Wang, W., Woods, G., Kutlar, A., Wright, E., Hagner, S., Tighe, F., Lewin, J., Cure, J., Zimmerman, R. A., & Waclawiw, M. A. (1998). Stroke prevention trial in sickle cell anemia. Controlled Clinical Trials 19(1), 110-129.
Adams, R.J., McKie, V.C., Hsu, L., Files, B., Vichinsky, E., Pegelow, C., Abboud, M., Gallagher, D., Kutlar, A., Nichols, F.T., Bonds, D.R., & Brambilla, D. (1998). Prevention of a first stroke by transfusions in children with sickle cell anemia and abnormal results on transcranial Doppler ultrasonography. New England Journal of Medicine, 339(1), 5-11.
Jones, A., Granger, S., Brambilla, D., Gallagher, D., Vichinsky, E., Woods, G., Berman, B., Roach, S., Nichols, F., Adams, R. J. (2005). Can peak systolic velocities be used for prediction of stroke in sickle cell anemia? Pediatric Radiology, 35(1), 66-72.
Krejza, J., Chen, R., Romanowicz, G., Kwiatkowski, J.L., Ichord, R., Arkuszewski, M., Zimmerman, R., Ohene-Frempong, K., Desiderio, L., & Melhem, E. R. (2011). Sickle cell disease and transcranial Doppler imaging: Inter-hemispheric differences in blood flow Doppler parameters. Stroke, 42(1), 81-86.
Pavlakis, S. G., Rees, R. C., Huang, X., Brown, R. C., Casella, J. F., Iyer, R. V., Kalpatthi, R., Luden, J., Miller, S. T., Rogers, Z. R., Thornburg, C. D., Wang, W. C. & Adams, R. J. (2010). Transcranial doppler ultrasonography (TCD) in infants with sickle cell anemia: Baseline data from the BABY HUG trial. Pediatric Blood Cancer, 54, 256-259.
Platt, O. S. (2005). Preventing stroke in sickle cell anemia. New England Journal of Medicine, 353(26), 2743-2745.
|Variable Name||Variable ID||Variable Description||dbGaP Mapping|
|PX821002060000||Angle-corrected mean velocities by automatic more||N/A|
|PX821002070000||Angle-corrected mean velocities by manual more||N/A|
|PX821002030000||Highest time-averaged mean blood-flow more||N/A|
|PX821002050000||Highest time-averaged mean blood-flow more||N/A|
|PX821002020000||Highest time-averaged mean blood-flow more||N/A|
|PX821002010000||Highest time-averaged mean blood-flow more||N/A|
|PX821002040000||Highest time-averaged mean blood-flow more||N/A|
Stroke Risk in Children with Sickle Cell Disease
July 30, 2015
A clinical test to measure the blood flow velocities in intracranial arteries. Elevated intracranial arterial blood flow rates are indicative of expanding vessel lesions and a subsequent increased risk of stroke.
This measure is used to stratify stroke risk in children to determine eligibility for prophylactic blood transfusion for stroke prevention.
Stroke, Stroke risk, Blood velocity, Transcranial Doppler ultrasonography, TCD, Imaging Transcranial Doppler ultrasonography, TCDi, Brain, Blood flow, "Neurology, Quality of Life, and Health Services"