title: Results from transcranial Doppler examination on children and adolescents with sickle cell disease and correlation between the time-averaged maximum mean velocity and hematological characteristics: a cross-sectional analytical study.
abstract: OBJECTIVE
  Transcranial Doppler (TCD) detects stroke risk among children with sickle cell anemia (SCA). Our aim was to evaluate TCD findings in patients with different sickle cell disease (SCD) genotypes and correlate the time-averaged maximum mean (TAMM) velocity with hematological characteristics.
  
  
  METHODS
  Cross-sectional analytical study in the Pediatric Hematology sector, Universidade Federal de São Paulo.
  
  
  METHODS
  85 SCD patients of both sexes, aged 2-18 years, were evaluated, divided into: group I (62 patients with SCA/Sß(0) thalassemia); and group II (23 patients with SC hemoglobinopathy/Sß(+) thalassemia). TCD was performed and reviewed by a single investigator using Doppler ultrasonography with a 2 MHz transducer, in accordance with the Stroke Prevention Trial in Sickle Cell Anemia (STOP) protocol. The hematological parameters evaluated were: hematocrit, hemoglobin, reticulocytes, leukocytes, platelets and fetal hemoglobin. Univariate analysis was performed and Pearson's coefficient was calculated for hematological parameters and TAMM velocities (P < 0.05).
  
  
  RESULTS
  TAMM velocities were 137 ± 28 and 103 ± 19 cm/s in groups I and II, respectively, and correlated negatively with hematocrit and hemoglobin in group I. There was one abnormal result (1.6%) and five conditional results (8.1%) in group I. All results were normal in group II. Middle cerebral arteries were the only vessels affected.
  
  
  CONCLUSIONS
  There was a low prevalence of abnormal Doppler results in patients with sickle-cell disease. Time-average maximum mean velocity was significantly different between the genotypes and correlated with hematological characteristics.
authors.affiliation: Department of Pediatrics, Universidade Federal de São Paulo, Brazil. mhoka@ig.com.br
authors.forename: Mary
authors.initials: M
authors.lastname: Hokazono
authors.forename: Gisele Sampaio
authors.initials: GS
authors.lastname: Silva
authors.forename: Edina Mariko Koga
authors.initials: EM
authors.lastname: Silva
authors.forename: Josefina Aparecida Pellegrini
authors.initials: JA
authors.lastname: Braga
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006400:Hematocrit; D006450:Hemoglobin SC Disease / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D018570:Risk Assessment; D020521:Stroke / Q000517:prevention & control; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods; D017086:beta-Thalassemia / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology