title: Intracranial resistive index (RI) values in normal term infants during the first day of life.
abstract: OBJECTIVE
  The purpose of this study was to determine normal resistive index (RI) values for term neonates during the first day of life as part of an ongoing prospective study of RI values in term infants with perinatal asphyxia.
  
  
  METHODS
  Forty normal term neonates underwent cranial sonography and Doppler during the first 24 h after birth. Transfontanelle Doppler was performed of the internal carotid, anterior cerebral, and middle cerebral arteries bilaterally. In addition, transtemporal Doppler was performed of the middle cerebral arteries bilaterally. Mean and median RI values were calculated in all vessels interrogated. The transfontanelle and transtemporal middle cerebral artery measurements were compared using paired t-tests.
  
  
  RESULTS
  The overall mean RI of all interrogated vessels was 0.726 with a standard deviation of 0.057. The mean RI value in the middle cerebral arteries was not significantly different with the two different measurement techniques.
  
  
  CONCLUSIONS
  Normal intracranial RI values for a term infant in the first day of life were calculated for comparison with RI values in term infants with perinatal asphyxia.
authors.affiliation: Arkansas Children's Hospital, Department of Radiology, Little Rock 72202, USA. jjs@george.ach.uams.edu
authors.forename: J W
authors.initials: JW
authors.lastname: Allison
authors.forename: L A
authors.initials: LA
authors.lastname: Faddis
authors.forename: D L
authors.initials: DL
authors.lastname: Kinder
authors.forename: P K
authors.initials: PK
authors.lastname: Roberson
authors.forename: C M
authors.initials: CM
authors.lastname: Glasier
authors.forename: J J
authors.initials: JJ
authors.lastname: Seibert
mesh_terms: D000367:Age Factors; D020771:Anterior Cerebral Artery / Q000502:physiology; D001238:Asphyxia Neonatorum / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000502:physiology*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000502:physiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D008297:Male; D020768:Middle Cerebral Artery / Q000502:physiology; D011446:Prospective Studies; D012016:Reference Values; D018608:Ultrasonography, Doppler; D017585:Ultrasonography, Doppler, Transcranial; D014655:Vascular Resistance