title: Normal ranges and test-retest reproducibility of flow and velocity parameters in intracranial arteries measured with phase-contrast magnetic resonance imaging.
abstract: BACKGROUND
  The purpose of the present study was to investigate normal ranges and test-retest reproducibility of phase-contrast MRI (PC-MRI)-measured flow and velocity parameters in intracranial arteries.
  
  
  METHODS
  Highest flow (HF), lowest flow (LF), peak systolic velocity (PSV), and end diastolic velocity (EDV) were measured at two dates in the anterior (ACA), middle (MCA), and posterior (PCA) cerebral arteries of 30 healthy volunteers using two-dimensional PC-MRI at 3 T. Least detectable difference (LDD) was calculated.
  
  
  RESULTS
  In the left ACA, HF was (mean (range, LDD)) 126 ml/min (36-312, 59 %), LF 61 ml/min (0-156, 101 %), PSV 64 cm/s (32-141, 67 %), and EDV 35 cm/s (18-55, 42 %); in the right ACA, HF was 154 ml/min (42-246, 49 %), LF 77 ml/min (0-156, 131 %), PSV 75 cm/s (26-161, 82 %), and EDV 39 cm/s (7-59, 67 %). In the left MCA, HF was 235 ml/min (126-372, 35 %), LF 116 ml/min (42-186, 48 %), PSV 90 cm/s (55-183, 39 %), and EDV 46 cm/s (20-66, 28 %); in the right MCA, HF was 238 ml/min (162-342, 44 %), LF 120 ml/min (72-216, 48 %), PSV 88 cm/s (55-141, 35 %), and EDV 45 cm/s (26-67, 23 %). In the left PCA, HF was 108 ml/min (42-168, 54 %), LF 53 ml/min (18-108, 64 %), PSV 50 cm/s (24-77, 63 %), and EDV 28 cm/s (14-40, 45 %); in the right PCA, HF was 98 ml/min (30-162, 49 %), LF 49 ml/min (12-84, 55 %), PSV 47 cm/s (27-88, 59 %), and EDV 27 cm/s (16-41, 45 %).
  
  
  CONCLUSIONS
  PC-MRI-measured flow and velocity parameters in the main intracranial arteries have large normal ranges. Reproducibility is highest in MCA.
authors.affiliation: Department of Radiology, Uppsala University, Uppsala University Hospital, 751 85, Uppsala, Sweden. mariacdev@hotmail.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Correia de Verdier
authors.affiliation: Department of Radiology, Uppsala University, Uppsala University Hospital, 751 85, Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Wikström
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D002533:Cerebral Angiography / Q000379:methods; D002536:Cerebral Arteries / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods / Q000592:standards; D018810:Magnetic Resonance Angiography / Q000379:methods / Q000592:standards*; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Blood flow velocity; Cerebral arteries; Hemodynamics; Magnetic resonance imaging; Phase-contrast MRI