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Updated: May 31, 2026
Functional Transcranial Doppler Ultrasound for Monitoring Cerebral Blood Flow
Published on: March 15, 2021
Sickle cell disease: reference values and interhemispheric differences of nonimaging transcranial Doppler blood flow
M Arkuszewski1, J Krejza, R Chen
1Department of Radiology, Division of Neuroradiology, University of Pennsylvania, Philadelphia, 19104, USA.
Insights
This study establishes reference values for transcranial Doppler (TCD) blood flow parameters in children with sickle cell anemia (SCD). These reference intervals aid in identifying children at high risk for stroke due to intracranial arterial stenosis.
Area of Science:
- Pediatric Neurology
- Vascular Ultrasound
- Hematology
Background:
- Transcranial Doppler (TCD) screening identifies children with sickle cell disease (SCD) at high risk of stroke.
- Elevated mean flow velocities in major brain arteries correlate with increased stroke risk.
Purpose of the Study:
- Establish reference values for interhemispheric differences and ratios of blood flow Doppler parameters.
- Focus on the internal carotid artery (tICA), middle cerebral artery (MCA), and anterior cerebral artery (ACA) in children with SCD using conventional TCD.
Main Methods:
- Established reference limits using a cohort of 56 neurologically intact children without intracranial stenosis.
- Utilized tolerance intervals to define reference limits for blood flow parameters.
- Included children with conventional TCD velocities <170 cm/s.
Main Results:
- Significantly higher average peak systolic velocities were observed in the right hemisphere for MCA and ACA.
- Provided reference limits for left-to-right differences and velocity ratios for MCA, ACA, and tICA.
- Found inverse relationships between flow velocities and age, hematocrit (Hct), or hemoglobin (Hgb).
Conclusions:
- The study offers essential reference intervals for TCD flow velocities and their interhemispheric variations.
- These reference values can assist in detecting intracranial arterial stenosis in children with SCD during sonographic screening for stroke prevention.
Background And Purpose:
TCD screening is widely used to identify children with SCD at high risk of stroke. Those with high mean flow velocities in major brain arteries have increased risk of stroke. Thus, our aim was to establish reference values of interhemispheric differences and ratios of blood flow Doppler parameters in the tICA, MCA, and ACA as determined by conventional TCD in children with sickle cell anemia.
Materials And Methods:
Reference limits of blood flow parameters were established on the basis of a consecutive cohort of 56 children (mean age, 100 ± 40 months; range, 29-180 months; 30 females) free of neurologic deficits and intracranial stenosis detectable by MRA, with blood flow velocities <170 cm/s by conventional TCD. Reference limits were estimated by using tolerance intervals, within which are included with a probability of .90 of all possible data values from 95% of a population.
Results:
Average peak systolic velocities were significantly higher in the right hemisphere in the MCA and ACA (185 ± 28 cm/s versus 179 ± 27 and 152 ± 30 cm/s versus 143 ± 34 cm/s respectively). Reference limits for left-to-right differences in the mean flow velocities were the following: -43 to 33 cm/s for the MCA; -49 to 38 cm/s for the ACA, and -38 to 34 cm/s for the tICA, respectively. Respective reference limits for left-to-right velocity ratios were the following: 0.72 to 1.25 cm/s for the MCA; 0.62 to 1.39 cm/s for the ACA, and 0.69 to 1.27 cm/s for the tICA. Flow velocities in major arteries were inversely related to age and Hct or Hgb.
Conclusions:
The study provides reference intervals of TCD flow velocities and their interhemispheric differences and ratios that may be helpful in identification of intracranial arterial stenosis in children with SCD undergoing sonographic screening for stroke prevention.
