title: Vascularity of the neonatal femoral head: in vivo demonstration with power Doppler US.
abstract: OBJECTIVE
  To detect the intrinsic blood supply of the unossified neonatal femoral head in vivo by using power Doppler ultrasound (US) and to ascertain whether a reduction in blood flow could be demonstrated with hip abduction.
  
  
  METHODS
  One hip of 13 neonates was examined with power Doppler sonography. After vessels within the femoral head were identified, the thigh was slowly abducted and the angle at which flow became undetectable was recorded. Spectral Doppler tracings were obtained in all subjects.
  
  
  RESULTS
  Intrinsic blood flow of the femoral head was demonstrated in all subjects. Flow became undetectable during hip abduction in 11 of 13 neonates and reappeared during adduction. The angle at which flow became undetectable varied from 60 degrees to 85 degrees. Spectral Doppler signals demonstrated a mixed arterial and venous trace.
  
  
  CONCLUSIONS
  Power Doppler US provides a simple real-time assessment of the femoral head blood supply. This may prove helpful in identifying neonates at risk of avascular necrosis, a complication of treatment of hip dysplasia with abduction hip restraints.
authors.affiliation: Department of Radiology, University of Cambridge, England.
authors.forename: P W
authors.initials: PW
authors.lastname: Bearcroft
authors.forename: L H
authors.initials: LH
authors.lastname: Berman
authors.forename: A H
authors.initials: AH
authors.lastname: Robinson
authors.forename: G J
authors.initials: GJ
authors.lastname: Butler
mesh_terms: D005270:Femur Head / Q000098:blood supply* / Q000000981:diagnostic imaging*; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging / Q000209:etiology; D006618:Hip Dislocation, Congenital / Q000628:therapy; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007103:Immobilization / Q000009:adverse effects; D007231:Infant, Newborn; D009068:Movement; D012039:Regional Blood Flow; D012307:Risk Factors; D018608:Ultrasonography, Doppler