title: [Effect of drug-induced vasodilatation of basal brain arteries with nitroglycerin on blood flow velocity and volume flow in the middle cerebral artery].
abstract: OBJECTIVE
  The Müller-Casty flow index (FI) is recommended for use in transcranial Doppler sonography (TCD) to measure relative changes in volume flow. We examined the ability of the FI to assess the volume flow during diameter changes of basal cerebral arteries.
  
  
  METHODS
  Nitroglycerin (NTG) was used to induce dilation of basal cerebral arteries without affecting cerebral blood flow. Transverse and sagittal sections of the middle cerebral artery (MCA) were obtained by magnetic resonance imaging (MRI) and blood flow velocities in the MCA were measured by TCD. The FI was calculated by multiplying Doppler shift frequency and signal power.
  
  
  RESULTS
  NTG induced an increase of MCA-diameter in MRI. The mean FI remained approximately constant (-2.6 +/- 6%), while the mean blood flow velocity dropped significantly (-15 +/- 6%).
  
  
  CONCLUSIONS
  The FI can be used to estimate volume flow in basal cerebral arteries even in case of diameter change.
authors.affiliation: Neurologische Kliniken der Charité, Berlin.
authors.forename: L
authors.initials: L
authors.lastname: Niehaus
authors.forename: S
authors.initials: S
authors.lastname: Gottschalk
authors.forename: U
authors.initials: U
authors.lastname: Weber
mesh_terms: D000286:Administration, Sublingual; D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D001810:Blood Volume / Q000187:drug effects; D001921:Brain / Q000098:blood supply*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000187:drug effects; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology*; D019291:Skull Base / Q000098:blood supply; D017585:Ultrasonography, Doppler, Transcranial / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin
vernacular_title: Einfluss medikamentöser Dilatation basaler Hirnarterien mittels Nitroglyzerin auf Strömungsgeschwindigkeit und Volumenfluss in der A. cerebri media.