title: Imaging of the intracranial vertebrobasilar system using color-coded ultrasound.
abstract: BACKGROUND
  Anatomic variety and difficult accessibility of the vertebrobasilar arteries pose considerable problems to conventional ultrasound. We evaluated the diagnostic potential of transcranial color-coded sonography in the distal part of this system.
  
  
  METHODS
  We insonated the intracranial section of the vertebrobasilar arteries through the foramen magnum window in 24 healthy individuals using a Doppler color flow imaging system in connection with a 2.5-MHz sector transducer. Magnetic resonance images in special inclination planes were performed and compared with the color-coded duplex images in five cases.
  
  
  RESULTS
  The B-mode image of the craniocervical junction and the intracranial parenchymal structures in addition to the color-coded blood flow allowed an unambiguous identification of the vertebrobasilar arteries (vertebral artery, 96%; basilar artery, 79%; and posterior inferior cerebellar artery, 50%). Blood flow velocities were measured considering the insonation angles: vertebral arteries, 50/24 cm/sec (30 degrees); basilar artery, 59/28 cm/sec (4 degrees); and posterior inferior cerebellar artery, 56/30 cm/sec (20 degrees) [peak systolic/end diastolic blood flow velocity (mean angle correction)].
  
  
  CONCLUSIONS
  Transcranial color-coded sonography enables accurate identification and differentiation of the intracranial vertebrobasilar arteries and improves accuracy of Doppler measurements. It may prove useful for evaluation of tortuosity and for hemodynamic studies in this vascular territory.
authors.affiliation: Department of Neurology, Justus-Liebig Universität Giessen, FRG.
authors.forename: M
authors.initials: M
authors.lastname: Kaps
authors.forename: G
authors.initials: G
authors.lastname: Seidel
authors.forename: T
authors.initials: T
authors.lastname: Bauer
authors.forename: B
authors.initials: B
authors.lastname: Behrmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001488:Basilar Artery / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D001783:Blood Flow Velocity; D002648:Child; D003116:Color; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012016:Reference Values; D012886:Skull; D014463:Ultrasonography / Q000379:methods*; D014711:Vertebral Artery / Q000033:anatomy & histology / Q000000981:diagnostic imaging*